PhotoModeler http://info.photomodeler.com Software for photogrammetry measurement and mapping from photos. Thu, 22 Jun 2017 20:59:34 +0000 en-US hourly 1 With A Camera and a Laser Reconstruct a Crime Scene http://info.photomodeler.com/blog/with-a-camera-and-laser-reconstruct-a-crime/ Mon, 19 Jun 2017 15:11:16 +0000 http://info.photomodeler.com/?p=3484 ...Read More]]> Unfortunately, this is an all too common story:

The convenience store clerk was alone when a man entered the store. He demanded money and cigarettes. When the clerk refused, the clerk was beaten and then shot, leaving no eyewitnesses to this horrific crime. But there was a ‘witness’ – the store had a single security camera.
The suspect’s face was not clear in the video, but he was imaged walking behind the cash desk and around the store. What next? The forensic specialist needed to extract some key measurements from the security video, such as the suspect’s height, some measurements on his clothing, and where he stood in the store at various times during the incident. How can these measurement be made from a single camera? Simulated Security Footage of Suspect Walking

Photogrammetry is the science of extracting measurements from photographs. Normally photogrammetry is carried out with multiple photographs taken from different positions. Sometimes it is difficult to extract data from single images.

Security cameraPhotoModeler can solve important information about the single camera and the scene at the time of the crime, by using the image captured at the time of the crime, and combining that with 3D data captured after the crime.

In this paper, ‘Extracting Accurate Measurements from Single Surveillance Camera Images’, by Eugene Liscio of ai2-3D Forensics, a detailed method is described using PhotoModeler to ‘marry’ the detail of a 3D laser scan with one still from a security camera, and then exported to 3D Studio Max for further analysis. In the paper Mr. Liscio simulated a scene due to the sensitive nature of the real forensic cases he works with, but the techniques described apply to real cases as well.

PhotoModeler had a recent update (version 2017.0 / Apr 10, 2017) that included a useful new capability that improves accuracy in these projects. Many security and surveillance cameras have wide angle lenses to maximize what they ‘see’. These wide angle lenses have significant lens distortion (straight lines are no longer straight).  To obtain accurate measurements you need to correct for this lens distortion.  PhotoModeler has always had lens distortion correction, but starting in the 2017.0 release, this correction can now be done in a single photo project as well.

The Steps

The paper goes into detail of the steps and process. Here are the rough steps.
Laser Scanner with Security Camera

  1. Grab video from security camera’s storage & get key frames.
  2. Use a laser scanner to produce a detailed 3d point cloud of the store as it exists today.
  3. Extract key 3D points from the laser scan data that match the scene as it was at the time of the crime (that is, if something has moved between the crime date and the date of the scan, don’t use that).
  4. Use PhotoModeler to mark these key ‘control points’ on the imported security footage.
  5. In PhotoModeler solve for the security camera position and internal parameters (including lens distortion).
  6. Lastly, either perform some plane-based measurements in PhotoModeler, or as the paper does, create an idealized version of the security footage and export to 3D Studio Max for matching and further analysis.

 

Another Approach and Example

In addition to the above referenced paper on the use of a laser scanner with a security camera, we published an article previously discussing the extraction of measurements and 3D data from a Dropcam camera used as a security camera in a small shop.

If you have any questions on how to use PhotoModeler in these types of forensic cases please contact us at sales@photomodeler.com.

 

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Subscription Sale Ending Soon & Two New Tips http://info.photomodeler.com/blog/sale-ending-and-new-tips/ Thu, 15 Jun 2017 15:30:47 +0000 http://info.photomodeler.com/?p=3474 ...Read More]]> PhotoModeler Subscriptions Sale Ending July 15th

A reminder that in one month the introductory sale for PhotoModeler Subscriptions ends. Get 25% off the subscription fees forever!

Subscriptions were first introduced in April 2017. Subscriptions are full licenses that auto-renew monthly or yearly. Subscriptions are a lower-cost entry point and help with cash flow management in businesses. Subscriptions are available for all 3 products: Standard, Scanner, and UAS. In addition to providing the license to run PhotoModeler for 1 or 12 months, subscriptions provide all updates and a reasonable amount of tech support.

If you purchase a Monthly or Yearly Subscription on or before July 15th, 2017 you will get 25% off your subscription price. And even better, if you don’t cancel that subscription, the discount remains in effect for all automated renewals forever! †

When purchasing a Subscription product in our store, use coupon code sub_intro_25 on the Cart page and press Apply.

Any price change to subscriptions introduced by Eos in the future may change your fee but if you have not cancelled since the first purchase, the 25% discount will be applied to the new price.

New Tip Videos

If you don’t follow PhotoModeler on Twitter or FaceBook, you may not have seen notice of our latest two tip videos. We have started the publication of tip videos again after a bit of a hiatus. The two new tip videos are:

  1. Showing a photo or point location on Google Maps: A PhotoModeler UAS project that has a defined geographic coordinate system provides a neat way to quickly look up a location in the project on Google Maps.
  2. Using, showing and hiding Reference Helper Lines: Reference helper lines are a great tool during manual referencing of points across photos, but sometimes they get in the way.

As well here is a link to all the tip videos on Youtube, sorted by most recent first.

 

Enjoy!  If you have any questions about the new tips or about the Subscription special please contact us at sales@photomodeler.com.

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PhotoModeler 2017.0.1/2 Releases http://info.photomodeler.com/blog/photomodeler-2017-0-12-releases/ Tue, 30 May 2017 21:17:25 +0000 http://info.photomodeler.com/?p=3365 ...Read More]]> On May 4th, 2017 PhotoModeler version 2017.0.1 was released, and on May 26th, 2017 version 2017.0.2 was released.

These releases provide many small improvements and bug fixes, and a few interesting new features. View the summary list of changes, or the complete list.

The interesting new capabilities in these two releases are:

  • New UAS tutorials. With the introduction of an easier workflow to generate a textured surface model in a SmartMatch project, the UAS Tutorial has been re-recorded. There are now three new UAV/drone focused tutorials: Introduction, Orthophotos, and Ground Control Points. See tutorial list.
  • Planar textures in 3D views. The 3D viewer has a new texturing method option based on the new ortho-mosaic method released in 2017.0. This method is great for 2.5D objects. It is faster and produces higher quality results (better color balance, sharper, and better blending).
  • Planar textures on 3D model export. The new ortho-mosaic capability released in 2017.0.0 is now available when exporting a 3D model using the planar texture option. You get a 3d model with mapped UVs onto a single orthographic texture map. Suitable for 2.5D surfaces. It is faster, produces higher quality results (better color balance, sharper, and better blending), and the texture map file is contiguous.
  • Improved ortho-photo world file. The world file exported optionally with ortho-photos (you use these when importing the ortho-photo or ortho-mosaic into geo-aware software), has improved accuracy for more geographic coordinate systems.

 

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With A Camera Perform Accurate and Detailed Surveying http://info.photomodeler.com/blog/with-a-camera-perform-accurate-and-detailed-surveying/ Mon, 15 May 2017 19:53:41 +0000 http://info.photomodeler.com/?p=3264 ...Read More]]> Surveying is an essential process in mapping, mining, construction, and architecture. This time and labor intensive process involves using a wide range of traditional and modern equipment to obtain measurements. Depending on the nature of the task, the required accuracy, and the challenges involved, a surveyor can use a tape measure/roller, a total station, a level, a laser scanner, or a photogrammetric tool. Most of today’s mapping, cadastral, and mining processes demand high accuracy surveys. Photogrammetry is a cost-effective method that also provides surveyors with accurate measurements. This technique entails generating models and measurements from photographic images. In this article, a few examples of the many uses of photogrammetric-based surveying are described.

Some mapping, mining, cadastral, and construction surveys are challenging and demand special measurement equipment. For instance, rock slope surveys involve taking measurements in terrains where it is difficult to use traditional tools. The photogrammetric technique enables surveyors to obtain accurate measurements in dangerous terrains and difficult to access locations. Unmanned aerial vehicle (UAV) photogrammetry provides reliable measurements that can be used for landslide characterization. Photogrammetric surveying is suitable for a wide range of applications including stock pile measurement, terrain analysis, urban planning, forest management, landfill monitoring, et cetera.

It is not easy to create accurate architectural restorations.  When used in architectural surveying, photogrammetry provides visually realistic and accurate 3D models. This technique is, therefore, an unmatched choice for architectural modelling.

Rock slope surveys using photogrammetry

When a rock slope needs stabilization, a survey of its shape and size can help. Rock slope surveys are required to determine suitable locations for metal stanchions and the amount of mesh required for the entire slope. Using the total station method, this exercise can take days to complete. In some locations, rock slopes can be as high as 100 meters. This makes it difficult for surveyors to take

Figure 2: Catchment area with debris

measurements accurately and safely using total station setups. The photogrammetric method enables surveyors to obtain accurate measurements quickly and without exposing themselves to risks. In this paper published in the American Surveyor, a company that specializes in rock slope surveys uses PhotoModeler, a photogrammetric tool. This technique enables the company to improve accuracy of measurements and save time. After obtaining photographic images, the software automatically detects matching features in overlapping photos. As compared to traditional methods of surveying rock slopes, the photogrammetric method provides more detailed 3D descriptions, in less time, with less risk.

Surveying a landslide using unmanned aerial vehicle photogrammetry

The stability of a landslide can be calculated using numerical method or limit equilibrium method. To obtain accurate calculations, accurate landslide geometric descriptions are required. As compared to traditional methods or conventional photogrammetry, unmanned aerial vehicle (UAV) photogrammetry provides more accurate landslide geometric descriptions. This approach combines both aerial and terrestrial photogrammetry and provides surveyors with reliable measurements. The UAVs can be autonomous, semi-autonomous, or remote controlled. This article on surveying a landslide using aerial vehicle photogrammetry describes how this technique is used to obtain accurate and reliable measurements.

Architectural surveying using photogrammetry

Figure 3: 3D model of a town

Photogrammetry allows creation of 3D architectural models that offer better perspective than ordinary maps or drawings. As compared to traditional methods of architectural surveying, the photogrammetric technique demands less time and effort and can produce interesting results with combined photographic textures. Figure 3 shows a 3D model of a historic town that was created using PhotoModeler. For architectural surveying, it is cheaper to use the photogrammetric technique than traditional surveying methods.

The second part of the American Surveyor article shows an architectural example using the method of photogrammetric survey for a redevelopment.

 

Conclusion

Photogrammetric surveying is a cost-effective method of obtaining accurate measurements from aerial or terrestrial photographic images. This technique is suitable for a broad spectrum of applications including terrain analysis, urban planning, architectural restoration, stability monitoring of structures, stock pile measurement, golf course layout, and so on. Aerial photogrammetric surveying enables surveyors to obtain accurate spatial information in high risk locations where traditional methods cannot be used. When used in difficult to access terrains, this surveying technique enables surveyors to take measurements with less effort. You can find more articles on photogrammetric surveying here.

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Efficient and Accurate Mapping with a DJI Matrice http://info.photomodeler.com/blog/efficient-and-accurate-mapping-with-a-dji-matrice/ Tue, 02 May 2017 23:46:07 +0000 http://info.photomodeler.com/?p=3176 ...Read More]]> The PhotoModeler partner, Klau Geomatics, is now selling their PPK (Post Processed Kinematic) GPS unit for DJI Matrice 100 and 600 UAV drones. This PPK unit, along with PhotoModeler’s PPK integration, provide excellent accuracy in ground surveying with minimal ground control.

To get high accuracy with a drone photo-based survey, one usually needs to place and survey several ground control points spread across the area. Ground control points are either man-made targets (e.g. large cross) that you place on the ground before the flight, or visible natural features, and both surveyed with a high accuracy instrument (total station or RTK GPS). Minimizing or removing the need for ground control points speeds up your survey and reduces cost. This can be achieved by knowing the location of the drone to high precision. This is where the PPK unit comes in.

The Klau Geomatics PPK unit is a high-quality GPS receiver mounted to your UAV drone. Typical UAV systems implement either a standard GPS unit with no corrections – provides only low accuracy position, or a real time kinematic (RTK) solution. RTK requires a stable radio link to receive base station data which is processed on the fly. RTK can be prone to GPS signal blockage and radio link outages with UAV flight dynamics, where signals are obstructed or lost over long distances.

An alternative to RTK is post processed kinematic (PPK), where all data is logged in the UAV and processed with base station data after the flight. There is no data loss or initialization loss as in RTK due to radio link limitations. All collected data is processed with similar algorithms to RTK, run forwards and backwards through the data. This ensures the most robust results possible. PPK offers greater flexibility in operations, longer range from the base, is more reliable, more accurate and easier to use.

DJI Matrice and PPK

Klau Geomatics PPK unit is now available for mounting on a DJI Matrice 100 or 600. An experiment was run with this PPK unit and a DJI Matrice 100 as pictured above.  The camera has 12 megapixels. The project had 89 still photos, flying height of 40m, and 6 ground control points (for use in initial calibration and for verifying measurement accuracy). The ground control points were collected on cross targets with a survey-grade RTK GPS unit.

Here are some of the photographs from the project:

The data was processed through PhotoModeler UAS software (first performing a camera calibration – needed only once per drone UAV), and then as a test with the ground control points as checks.  Here is a summary table of the deltas between the solved camera positions (solved by PhotoModeler UAS) and the PPK GPS positions.

We can see the RMS error on the 89 camera positions was 8.3 cm.

Here is a summary table out of PhotoModeler UAS using a previously calibrated camera and using two of the ground control points to simulate a minimal control situation. The summary shows the deltas between the control points and the positions solved by PhotoModeler – the 4 points used as checks only for comparison, and 2 points used in processing.

We can see the RMS error on the 6 ground control positions was 6.1 cm.

Here are the 6 ground control point deltas individually. The first two in table were carried in the adjustment and the rest are check points alone.

It is great to see such high accuracy with an efficient processing method on a popular DJI drone. If you have any questions on the PPK unit or PhotoModeler please contact either Eos Systems or Klau Geomatics.

 

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With a Camera Measure Shape and Movement in Sails and Flexible Structures http://info.photomodeler.com/blog/with-a-camera-measure-shape-and-movement-in-sails-and-flexible-structures/ Mon, 24 Apr 2017 08:10:43 +0000 http://info.photomodeler.com/?p=2798 ...Read More]]> With A Camera Blog Series

In our second of the series we describe a unique and interesting application of measuring fabrics, sails, and flexible structures – something that is very hard to do with other methods.

 

 


Introduction

Fig. 1 Model of easing sail

Flexible structures, such as sails, fabrics, flexible wings, and solar sails are very hard to measure because they are unstable. For example, the instability of the shape of a sail due to wind and luffing makes it difficult for sail designers and flow analysts to measure flying shapes of yachts and spinnakers in real sailing conditions. In a sail, the light fabric plays a critical role in generating the force that drives it, hence the need to optimize its shape. Similar difficulties exist with flapping wings, and gossamer space structures.

Accurate 3D descriptions of objects in the wind tunnel enable flow analysts to validate numerical predictions. Furthermore, flying shapes provide sailors with critical trimming tips that they can employ during racing competitions. For a long time, researchers have been looking for suitable methods for measuring shape and movement of flexible structures.

Application of Photogrammetry in sail shape acquisition

Spinnaker with targets

Fig. 2 – Spinnaker with targets

Various flying shape measurement techniques have been developed and tested. These measurement techniques include laser-based method, profilometric technique, and photogrammetric measurement. The laser-based technique requires time to scan a sailing object, and this makes it unsuitable for dynamic measurements. The photogrammetric method provides accurate 3D measurements at one instant in time, and this makes it a reliable source of information for validating numerical simulations. The PhotoModeler software provides such tools.

The photogrammetric technique involves generation of 3D descriptions of fluid-structure interactions from high resolution photographs. The fabric of the sailing object is fitted with markers at discrete points as shown in Figure 2. The high resolution images are captured simultaneously from different viewing angles using digital cameras. The photogrammetry algorithm converts 2D coordinates of points in the sailing object’s images into 3D coordinates points, which are then lofted to generate spline curves. A non-uniform rational b-spline surface is produced by lofting the spline curves. A detailed procedure is described in this Spinnaker Modeling Paper. The capture of shape over time and animated rendering shows the 3D model of a real spinnaker as it is trimmed,  as shown in Figure 1 above.

The experiment requires at least three cameras, and each is calibrated before the experiment to ensure accuracy of the obtained measurements. You can find more resources on how you can enhance the accuracy of your photogrammetric measurement system here. The flying shapes obtained from photogrammetric measurements enable flow analysts and sail designers to validate analytical simulations and optimize the performance of flexible structures. This technique allows fast sampling, and it is cost-effective as compared to other techniques used for flexible structural monitoring.

Solar Sails and Space Structures

Fig. 3: Solar Sail – credit NASA

The flexibility and lightness of gossamer structures makes it difficult for researchers to measure their 3D static shapes. Sensors cannot be used because their weight can interfere with the dynamic characteristics and shapes of the ultra-weight structures. The laser-based technique is slow, and it is, therefore, likely to produce inaccurate measurements. Photogrammetry provides NASA and the aerospace industry with a suitable ground test method for measuring gossamer structures under various conditions. The technique allows researchers to measure such structures under stationary, vibrating, and deploying conditions. This article on NASA solar sails describes how a senior research engineer at NASA used photogrammetry to measure 3D static shapes of gossamer structures.

The 3D static shapes obtained from this non-contact measurement technique are used to validate analytical predictions obtained through advanced simulations. Using validated structural models gives NASA and the aerospace industry the confidence that the ultra-lightweight space structures will perform as planned when they are launched to the space. The measurements are also used for fine-tuning the designs of the deployment systems and evaluating their performance under dynamic loads. Measuring the 3D static shape of gossamer structures involves installing targets on the delicate membrane. However, it has been demonstrated that accurate photogrammetric measurements can be obtained by projecting targets on the delicate structure.

Micro-aircraft Flexible Wing Modeling

Fig. 4: Micro-AV Test Setup

Accurate modeling of the wing motion enable researchers to study the dynamics that are involved in flapping flight of micro aircraft. The measurements also enable them to study the effects of changing the shape of a wing during flight. Photogrammetry provides researchers with a suitable testing method for analyzing the performance of flapping wings under different conditions. These measurements are used by researchers for optimizing the designs of flapping wings for micro air vehicles (MAV). In this thesis on MAV, a non-intrusive photogrammetry technique that employs laser dot projection was used to measure the shape of a flapping wing.

Summary

The fluid-structure interaction between a light fabric and a complex flow complicates the process of measuring flying shapes. Photogrammetry provides an accurate technique of developing three-dimension descriptions for validating numerical simulations of objects in real conditions. Sail designers and flow analysts require 3D descriptions to optimize the design of the flexible parts of sailing objects. Photogrammetric measurements are also used by NASA and the aerospace industry for fine-tuning the designs of ultra-lightweight space structures. Additional engineering and scientific measurement scenarios can be found on the PhotoModeler Engineering Applications page.

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PhotoModeler 2017 Release http://info.photomodeler.com/blog/photomodeler-2017-release/ Wed, 12 Apr 2017 18:33:42 +0000 http://info.photomodeler.com/?p=3049 ...Read More]]> On April 12th, 2017 we released the new 2017.0 version. This version has some significant improvements and changes:

Subscription Licensing

As of April 12, 2017 you have the option of buying a monthly or yearly subscription to any of the three PhotoModeler products (Standard, Scanner, UAS). The permanent license remains available for purchase.

Subscriptions are time-limited full licenses that auto-renew. Subscriptions are a lower-cost entry point and help with cash flow management in businesses. Subscriptions are available for monthly or yearly renewal.

In addition to providing the license to run PhotoModeler for 1 or 12 months, subscriptions provide updates and tech support. Subscriptions are purchased in our store.  Ask us about an introductory special.

Revamped Ortho-mosaics

Ortho-photo from tutorial project

An Ortho-mosaic or Ortho-photo is a computed output that shows an orthographic representation of a surface in photographic form. A mosaic takes input from multiple input photos and produces one output photo. In other words, a photo that can be used as a 2D drawing. Ortho-mosaics are especially useful with drone/UAV projects where hundreds of photos are combined into one useful, accurate output photograph.

PhotoModeler’s ortho-photo capability had a significant revamp in 2017.0. It has a superior color balancing system for a more consistent and better looking output; it is more efficient in speed and resources; and it can produce very large, detailed output without running out of memory. Look at our new ortho-photo samples. Includes a 50,000 x 34,0000 (1.7 giga pixels) output!

Automated Low Density Surface Creation

Often when first processing a SmartProject you’d like to quickly see a surface with textures or create an ortho-photo / ortho-mosaic – but you don’t want to have to go through the extra steps of MVS right away. With this new capability a low density surface is created by request with all new SmartProjects. After processing you can then quickly view a textured model or create an ortho-mosaic.  Once you are satisfied with the low density model you can optionally use the MVS tool to create a more detailed high density surface mesh.

Single Photo Calibration Improvement

This is a rather specialized improvement but has often been requested by our customers doing forensic work with surveillance cameras. Surveillance cameras tend to have lenses that are quite wide angle and consequently have large lens distortion. If you are trying to get accurate measurements from a frame of this video (typical in a store robbery scenario) you need to account for lens distortion. PhotoModeler can now perform lens distortion calibration from a single image making this task much easier. It is a neat tool for combining a laser scan of a scene with a historical frame from a surveillance camera.

Updating to the Latest

If you are an existing PhotoModeler customer, and your Maintenance Agreement is active, you can update to the latest version from the software or download online.

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With a Camera Determine Who Caused a Collision http://info.photomodeler.com/blog/with-a-camera-determine-who-caused-a-collision/ Wed, 22 Mar 2017 22:05:23 +0000 http://info.photomodeler.com/?p=2932 ...Read More]]> A New Blog Series

We introduce a new blog series called
With A Camera“. With each blog post in this new series we describe an application of close range photogrammetry – that is, 3D measurement and modeling with a camera.

The articles will describe significant real-world problems and how photogrammetry was able to uniquely solve them. Future topics might include engineering, surveying, architecture, construction, drones, mining, agriculture, forensics, scientific and industrial measurement, and archaeology. In each post, we will summarize the problem, how it was solved, and as well point out resources on the web for further study. The first post of this new ‘With A Camera’ series is the interesting one of measuring accident and collision scenes.


Collisions and Photogrammetry

The process of reconstructing a traffic accident to determine who caused it demands detailed accident scene diagrams and often a determination of key causes, such as speed. Some of the details that are required include positions of the vehicles involved in the accident, skid mark locations, roadway features, and impact locations. It is challenging to create accurate collision scene diagrams and keep road closures to a minimum while ensuring investigator safety. It is even more challenging when creating these diagrams from a limited number of photographs that you did not take! Photogrammetry allows incident investigators and traffic accident reconstructionists to create scaled collision scene diagrams from scene photos they took and as well from unknown photo sources.

To determine vehicle speed at impact, measuring the crush of a vehicle can be important. It is difficult to obtain highly accurate vehicle crush measurements using physical inspection equipment such as tape measures, crush deformation jigs, and measuring poles. These techniques use a “guessed” pre-impact boundary shape/position. In comparison, photogrammetry utilizes known pre-impact and post-impact positions. Studies have shown that photogrammetry provides more accurate results as compared to hands-on physical measurements.

Accident Scene Diagramming Using Photogrammetry

Accident scene aerial view

Collision scenes are documented by two parties. One group are incident investigators usually attached to the police force, and the other are 3rd party reconstructionists. Traffic accident reconstructionists are usually not available at the scene immediately after the accident has occurred. They visit the collision scene when the debris has already been washed away and skid marks cleared. In many cases, they rely on unknown images to create scaled road diagrams. This page on mapping accident scenes describes how PhotoModeler is used to create accident scene diagrams.

To create accident scene diagrams from an unknown photograph, reconstructionists can use new photographs they take during site investigation together with the old photographs taken at the time of the incident by the police or other parties such as bystanders. Although the new photographs lack critical details of the incident that has long been cleared, they share common reference points with the old photographs. These discrete points may include lane lines, light posts, street corners, and other identifiable marks.

To create accurate collision scene diagrams, the characteristics of the camera used to capture the unknown photograph are required. These characteristics are obtained through a process known as inverse camera. This process is used to determine the focal length, position, and orientation of the camera. The process involves identifying control points in the old photographs, determining real world coordinates, and solving a set of equations to obtain the unknown camera characteristics.

After obtaining the unknown characteristics, the next step entails finding the relationship between the old photograph and the surface of the object in 3D space through a process known as photographic rectification. The obtained three-dimensional relationship is used to generate a re-mapping of the surface. PhotoModeler allows accident reconstructionists to perform both inverse camera projection and photographic rectification. This paper on diagramming an accident scene describes how photogrammetry is used to create accurate collision scene diagrams.

 

Determining Speeds Using Photogrammetry

Measurement points on a damaged car

To help determine the speed of collision (which can help with causation), measuring the amount of crush on a vehicle can be helpful, as can measuring skid mark length. There exists a linear relationship between vehicle crush and the equivalent barrier speed. To start with, reconstructionists obtain crush measurements that they use to compute crush energy. The equivalent barrier speed is then computed directly from crush energy. Some of the common techniques of measuring crush include measuring poles, grid, tape measures, and photogrammetry. Except for the photogrammetric method, all the other techniques use “guessed” pre-impact boundary position/shape.

The photogrammetric technique uses known pre-impact boundary position/shape and post-impact boundary shape/position for crush measurement. This process involves creating 3-D models of both cases and then superimposing them to obtain crush measurements. After obtaining the measurements, the vehicle stiffness data is used to compute crush energy. Correlation method is then used to determine pre-impact speed from the crush energy. This paper on determining equivalent barrier speeds describes how PhotoModeler is used in vehicle crush measurement.

Studies have established that both physical inspection and photogrammetric analysis are suitable techniques for measuring vehicle damage. However, according to the findings of the study described in this research paper, photogrammetric analysis provides more accurate results as compared to hands-on measurement techniques.  In addition, the technique is more convenient and inexpensive.

Conclusion

Photogrammetry allows car accident reconstructionists to create accurate scene diagrams from known and unknown photographs. This process involves using photographs provided by the police and 3rd parties, and new photographs that are taken by the reconstruction team during the site investigation. In addition, photogrammetry enables traffic accident reconstruction experts to accurately measure vehicle crush and determine equivalent barrier speeds. Recently, the use of drones and UAVs has picked up in scene diagramming because photogrammetry provides the perfect measurement and diagramming tool from drone photography. In addition, here are more articles on applications of photogrammetry in forensics and car accident reconstruction.

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PhotoModeler 2016.2 Release http://info.photomodeler.com/blog/photomodeler-2016-2-release/ Mon, 28 Nov 2016 18:24:51 +0000 http://info.photomodeler.com/?p=2471 ...Read More]]> PMU TutorialPhotoModeler 2016.2 was released Nov. 28th, 2016.

This release has three significant improvements:

  • PPK – GPS Post Processing Kinematics Support
  • UAV / drone video tutorial with real UAV data
  • Processing speed improvements

For further information on PPK and how to do high accuracy surveys with drones see the PPK blog post.

There is a new a step-by-step tutorial video (with included real world data) that demonstrates creating a UAV/drone project that has GPS camera data and ground control points (GCPs). You can download the data and follow along yourself.  The data will load into the PhotoModeler UAS Demo as well.  The tutorial video can be seen here and the project data (with photos, gcp file, and sample projects) is available in a zip file at the bottom of the tutorials page.

The speed improvements come in the orientation stage of Smart Projects in PhotoModeler Scanner and PhotoModeler UAS.  Projects (esp. ones with a large number of photos) complete much more quickly now.

In addition there were 13 improvements, and 20 fixes.

The update is available on the Support Updates page, or via Check for Updates within the software.

 

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Survey Grade Accuracy with a Drone without Ground Control ! http://info.photomodeler.com/blog/survey-grade-accuracy-with-a-drone-without-ground-control/ Tue, 08 Nov 2016 14:05:43 +0000 http://info.photomodeler.com/?p=2412 ...Read More]]>

Ground Control Point seen from drone camera

To get high accuracy with a drone photo-based survey, one usually needs to place and survey ground control points. Ground control points are either man-made targets (e.g. large cross) that you place on the ground before the flight, or visible natural features, surveyed with a high accuracy instrument (total station or RTK GPS).

To achieve 2 cm to 4 cm ground accuracy from your drone survey over the whole area usually requires 10 or more ground control points. These ground control points (GCPs) require travel over the whole site, take time to place, survey, and optionally remove, and thus are an expensive method. Any way to reduce ground control requirements is money and time in your pocket!

How can you reduce the number of ground control points or remove them completely? You can do that by knowing where you drone was to high accuracy during the flight and for each photograph. Most drones have a built-in GPS (and IMU + barometric altimeter) for navigation but the positional data (esp. in an absolute sense) is not that accurate. A photo-based survey carried out with a modern drone, with its own GPS/ positional data, will be in roughly the correct part of the world and its relative accuracy will be reasonable but its absolute accuracy may be good only to around 5 m to 10 m. On the other hand, if you know where the drone is during photography to high accuracy you can achieve much higher ground survey accuracy.

The way to do that is using a differential method for the drone GPS/GNSS receiver. RTK and PPK (Real Time Kinematics and Post Processed Kinematics) GNSS are the ways to do that. For this application, PPK is often superior because real time position is not required, and PPK requires no radio link so it is more reliable and works over greater distances than RTK. In addition, more processing power can be applied to the PPK position solutions since the processing is done back at the office on your computer and not on a smaller GNSS receiver.

PPK Receiver (white box with black antenna) mounted on drone above camera.

The PhotoModeler UAS product has a new PPK system built in that lets you reduce or remove the requirements for ground control. Imagine the cost and time savings when you are doing accurate surveys using your drone! The PPK system in PhotoModeler UAS uses data from the Klau Geomatics PPK system. This PPK system is made up of a light-weight, high-quality GNSS receiver that attaches to your drone, and a base station (the base can be another unit sold by Klau Geomatics, your own GNSS reference station, or a CORS). When you return from your flight you load the photos from the drone camera, the data from the drone PPK unit, and the data from the base station into PhotoModeler UAS and hit process. The result is a highly accurate ground survey in the form of a point cloud, or optionally a dense mesh, contours, 3D file export, or an orthophoto.

Here are some results from a real-world test with a KG PPK unit and processed with PhotoModeler UAS. The goal of this test was to see how accurate a survey without ground control could be. The camera and system were first calibrated. A new project was started without any ground control and using just the PPK camera position data as external input.  The ground control points were then imported but to be used only as check points. The control points did not affect the adjustment or processing (they were imported after the processing) but instead could be used just to compare the solved 3D locations of those points with the external data as a ‘check’.  The ground control points were marked on the photos so that PhotoModeler UAS could compute their 3D location (using just the previously solved camera positions and camera calibration), and a report was generated.

Here are the results of the check of 9 ground control points:

gcp-fit-table

The RMS error, which is similar to the one sigma precision, shows an error of approx. 2 cm in Northing and Easting and 6 cm in elevation. This is survey grade accuracy using no ground control points in the solution!  The elevation error could probably be improved further using one or two ground control points if that was important (you could even use the drone after landing to do that).  Here is a link to the full PPK PDF Report generated by PhotoModeler UAS for this project.

 

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Time Limited Discount for PhotoModeler UAS http://info.photomodeler.com/blog/time-limited-discount-for-photomodeler-uas/ Wed, 02 Nov 2016 15:38:51 +0000 http://info.photomodeler.com/?p=2395 ...Read More]]> camera-stations-with-colorized-groundWe officially announced PhotoModeler UAS to the world late last week, after a soft-launch a couple of weeks ago. See the press release that was published Oct. 26th, 2016 (also included in full below).

PhotoModeler UAS (PhotoModeler for Unmanned Aerial Systems) is photogrammetry software optimized with new features for drone / UAV users. See the PMU product page.

To celebrate this release, and our exhibiting of PMU at the Commercial UAV Expo Nov. 1st and 2nd in Las Vegas, we are offering a time limited discount for the new product. Between Nov. 1st and Nov. 30th, PhotoModeler UAS (and trade-ups from other PhotoModeler products) will be 35% off. Contact Eos Systems to get the store discount code.†

The PhotoModeler UAS list price is $3495usd, and for this limited time at 35% off, it will be $2275usd.

With this purchase you would receive a perpetual license for PhotoModeler UAS as well as one year of free updates and support. We are continually improving the speed, completeness, correctness and features of PMU, so rest assured if you buy in November the product will only get better over time!

Please contact us today at sales@photomodeler.com for your store discount code.†


The Oct. 26th press release:

Eos Introduces New Photogrammetry Software Optimized for Drone Photography

Eos Systems Inc. has introduced new photogrammetry software optimized specifically for photographs taken with drones or unmanned aerial systems (UAS). The new PhotoModeler UAS 2016 software creates 3D models, measurements, and maps from photographs taken with ordinary cameras built-in or mounted on drones. It includes numerous features for optimized operation with drone photos including post processing kinematics (PPK), volume objects, full geographic coordinate systems support, multispectral image support and control point assist. Eos Systems will be showing the new PhotoModeler UAS product at the Commercial UAV Expo in Las Vegas, Oct. 31 to Nov. 2, 2016 and will offer the new software at $2275, 35% off the normal price, from November 1 to November 30, 2016.

The new version of PhotoModeler is ideally suited for drone photogrammetry applications including surveying, ground contouring, surface model creation, stock pile volume measurement, mining and mine reclamation, environmental analysis, slope analysis, forensic analysis, construction, and agricultural crop analysis. New applications for drone photogrammetry are developed monthly. Eos PhotoModeler was introduced 23 years ago and has become one of the leading photogrammetric software platforms with a wide range of users in fields such as architecture, engineering, surveying, research, manufacturing and forensics.

PhotoModeler UAS 2016 software includes numerous features that provide higher performance in drone photogrammetry. Camera calibration is optimized for high accuracy with UASs and the global positioning system (GPS). Post processed kinematics (PPK) makes it possible to correct a survey with GPS data after the fact for survey grade accuracy. Volume objects provide easy and accurate volume data for stock piles and mining operations. Full geographic coordinate system support enables users to work in their local geographic coordinate system for better compatibility. Support is provided for multispectral images including Normalized Difference Vegetation Index (NDVI) surface models and ortho-mosaics for precision agriculture. An intuitive interface is provided for efficiently marking ground control points.

About Eos Systems
Eos Systems Inc. is the developer of the PhotoModeler software, and has been a leader in versatile close-range photogrammetry solutions for more than 23 years. Our PhotoModeler software is used by thousands of companies world-wide in engineering, architecture, surveying, crime and accident reconstruction, and film or video production, among others. The software is also optimized for users of UAV / drone photography to generate real world measurements and maps. Eos Systems is headquartered in Vancouver, British Columbia, Canada. For more information about Eos Systems, visit www.photomodeler.com.

Eos Systems Press Contact
Matt Klymson
matt@photomodeler.com
1-866-532-6658 / 1-604-732-6658


† The price and discount available on the PhotoModeler store (info.photomodeler.com/store) may not be available or may be a different amount when purchased through a reseller.

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PhotoModeler 2016.1 and PhotoModeler UAS Release http://info.photomodeler.com/blog/photomodeler-2016-1-and-photomodeler-uas-release/ Mon, 26 Sep 2016 21:08:31 +0000 http://info.photomodeler.com/?p=2270 ...Read More]]> Drone in skyThere is a lot of excitement over drones and UAVs these days, and rightly so! UAVs bring new a capability to inspect, document, measure and model objects and larger scenes that is difficult to do from the ground. They literally give you a new perspective! As well, more PhotoModeler customers are taking on 3D measurement, modeling and mapping tasks with drone and UAV photography.

You’ve been asking for improved capabilities and new features to make your work easier in mining, stock pile monitoring, agriculture, accident scene mapping and other similar tasks that are well addressed by photos taken from the air.

We have been working hard in the last year to create some very powerful new capabilities in PhotoModeler for UAV work, and as a result we are releasing a new product called PhotoModeler UAS, or ‘PhotoModeler for Unmanned Aircraft Systems’, today.

New Product Line Up

Our line up has been restructured into these three PhotoModeler products:

  • PhotoModeler Standard
  • PhotoModeler Scanner
  • PhotoModeler UAS

The existing product PhotoModeler Motion is being retired and its capability for tracking 3D objects over time will be rolled into both PhotoModeler Scanner and PhotoModeler UAS.

The release of PhotoModeler UAS and the product line-up reorganization coincides with the new version PhotoModeler 2016.1. There have been numerous updates to all three products with improvements, bug fixes and new features.

PhotoModeler UAS

PhotoModeler UAS is aimed at those using UAV / drone platforms for generating surface models, orthophotos, or volume measurements.

The following lists the features that are included in the new PhotoModeler UAS (PMU):

Powerful UAS-Focused Processing
The process that takes images as inputs and produces accurate 3D and map data as output, has powerful capabilities that make more UAS projects possible. For example, the processing has new capabilities to handle GPS data from your UAV to improve accuracy and speed (e.g. a 230 photo project to mark, match & orient took 1.5 hours, but only 45 mins in PMU).
Volume Objects
Easily model and measure stock piles or other similar terrain shapes, and obtain accurate volumes.
Multi-spectral Image Support
In agriculture and biological fields create and export 3D models or ortho-mosaics with draped multi-spectral image analyses such as NDVI, CIR, G-NDVI, and SAVI.
Geographic Coordinate Systems
Import surveyor data, and export 3D and 2D data in a geographic coordinate system such as UTM, state plane or Latitude/Longitude. Work in a system compatible with your GIS or mapping system.
PDF Report Generation
Generate a nicely formatted summary report of the project in PDF format. Suitable for internal documentation or sending to clients.  Here is a sample pdf report generated by PMU.
Contours (major/minor)
Create, display, overlay and export minor contours with a different look than major contours. A great visualization of height used by map makers.

The PhotoModeler Products page outlines the differences between the three products.

New UAS Videos

There are two preliminary videos showing some of the new PhotoModeler UAS functionality. More to come!

PhotoModeler 2016.1 Changes

In addition to the new PhotoModeler UAS product, PhotoModeler and PhotoModeler Scanner also received a number of improvements and fixes.  One goal of 2016.1 was to improve stability as well.  Some of the significant changes in 2016.1:

  • Locate function:  more easily find 3D imported points and 3D project points on photos before they have been marked using new Locate and Find Projected functions.
  • Photo-texturing improvements:  quality textures are generated only once and have higher resolution (map per mesh now instead map per project).
  • UI speed improvements: for projects with larger number of photos there have been a number of speed improvements in the user interface.
  • Orthophoto quality improvement: orthophotos have a new subpixel method to give higher quality (as seen at higher zooms)
  • Background check for updates: once per day (under user control) PhotoModeler will check for any updates available and inform you – easier to stay up to date with fixes.
  • Auto-calibration improvements (scanner): Camera auto-calibration has been improved and made more stable providing better camera calibrations in more cases.

If you are one that likes detailed lists you might be interested in seeing the complete list of 2016.1 changes to all 3 products.  Start reading this changes page from ‘2016.0.9 – BETA [July 20, 2016]’ and up (2016.0.8 was most recent public release).

Getting the New Product or New Release

If you are a current customer and have an active maintenance subscription, get the update. You can also use Check for Updates within the PhotoModeler software.

If you are new to PhotoModeler and would like to evaluate the new version or new product, download it. You will have 10 days of full capability (load your own photos, export models, etc.).  To purchase PhotoModeler UAS visit the PhotoModeler Order page.

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PhotoModeler At Upcoming Trade Shows http://info.photomodeler.com/blog/photomodeler-at-upcoming-trade-shows/ Tue, 12 Apr 2016 21:53:30 +0000 http://info.photomodeler.com/?p=2012 ...Read More]]> PhotoModeler at WREX and ARC-CSI 2016 conferences

WREXandCSIConfLogosCome join us at the PhotoModeler area at both the WREX 2016 World Reconstruction Exposition, May 2-6 in Orlando, FL (www.wrex2016.com) and the ARC-CSI Crash Conference, May 23-26 in Clark County, NV (www.arccsi.com).

Accident reconstructionists can consult with our experts about best practices for the use of PhotoModeler in collision investigations. Topics include incident scene mapping from UAS/drone, combining photogrammetric data with other survey devices like total station or laser scanner, standalone use of PhotoModeler for scene surveys, using 3rd party photos from unknown cameras, and presenting photogrammetric evidence in court.

 

 

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PhotoModeler 2016.0.6 Release http://info.photomodeler.com/blog/photomodeler-2016-0-6-release/ Tue, 29 Mar 2016 17:15:11 +0000 http://info.photomodeler.com/?p=1990 ...Read More]]>
2016.0

PhotoModeler 2016.0.6 was released Mar. 24th, 2016.

The main reason for this release was to improve stability and fix user-reported crashes and problems. There were 9 crash fixes, 5 fixes to non-crash items and 7 small improvements.

We have found that PhotoModeler 2016’s new crash reporting tool (that sends data to us in the event of a crash) is helping us track down some of the rare and esoteric crashes. It is almost impossible to fix a bug if we can’t reproduce it here and the new crash reporting tool helps us do that. It is not perfect, but we do like how it has helped improve the stability of PhotoModeler for our customers.

One of the crashes that was quite annoying to customers was in the referencing area. This crash could occur during referencing or even when just moving the cursor when in referencing mode.  With a number of reports of this, and some customers kindly sharing their projects, we were able to track it down and fix it in this release.

As well, two improvements of note:

a) If you export large triangulated meshes to .obj, .wrl, .3ds, or .fbx formats you’ll like the speed increase. We’ve seen a large mesh export speed up as much as 50 times!

b) PhotoModeler Scanner allows one to keep multiple dense surface models in a project at once. While this is a powerful feature, it can be confusing at times esp. if your end goal after multiple runs, edits, etc. is just one dense surface model. There is a new dialog that gives you the option to keep only one dense surface model when one is created. You can now work with multiple dense surface models or just one, at your preference.

 

Getting the New Release

If you are a current customer and have an active maintenance subscription, get the update. You can also use Check for Updates within the PhotoModeler software.

If you are new to PhotoModeler and would like to evaluate the new version, download it. You will have 10 days of full capability (load your own photos, export models, etc.). After 10 days it switches to a restricted Demo mode – and extension codes are available from PhotoModeler resellers.

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PhotoModeler 2016.0.5 Release http://info.photomodeler.com/blog/photomodeler-2016-0-5-release/ Tue, 16 Feb 2016 18:20:11 +0000 http://info.photomodeler.com/?p=1865 ...Read More]]>
2016.0

PhotoModeler 2016.0.5 was released Feb. 16th, 2016.

The main reason for this release was to improve stability and fix user reported crashes and problems. There were 10 crash fixes, 4 fixes to non-crash items and 4 small improvements.

 

Getting the New Release

If you are a current customer and have an active maintenance subscription, get the update. You can also use Check for Updates within the PhotoModeler software.

If you are new to PhotoModeler and would like to evaluate the new version, download it. You will have 10 days of full capability (load your own photos, export models, etc.). After 10 days it switches to a restricted Demo mode – and extension codes are available from PhotoModeler resellers.

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PhotoModeler 2016.0 Release http://info.photomodeler.com/blog/photomodeler-2016-0-release/ Wed, 27 Jan 2016 20:56:50 +0000 http://info.photomodeler.com/?p=1686 ...Read More]]>
2016.0

PhotoModeler 2016.0.4 was released Jan. 27th, 2016 after a year of intense development and a couple of months of beta testing.

One of the main focuses of this release is improved results with drone / UAS / UAV projects. The software is much faster processing larger numbers of photographs, handles control points with more flexibility, and reads GPS data from drone image headers.

The improvements will help many different types of large projects in PhotoModeler Scanner (not just drone projects). As well there are numerous other changes that impact all three versions of the software.

The major improvements are:

New Smart Project Robust Orient. The photo orientation algorithm used in Smart Projects has undergone a complete rewrite. The major objective was speed improvements – esp. with projects with large numbers of photos (such as drone/UAS projects). It also has improved camera auto-calibration, and has greater flexibility with control point minimums.

Demo / Eval Changes. The Demo/Evaluation system has been revamped to allow for an initial full-capability evaluation period on download, after which PhotoModeler goes into a restricted Demo state. A Trial/Evaluation code can still also be requested.

GPS Camera Stations. Photos that contain GPS data (common with drone/UAS photos) can be automatically setup with a geo coordinate system and display in the 3d viewer.

Scripting. Script commands can be run from within PhotoModeler and/or by loading a text file. External control with DDE remains.

False color surfaces. Triangulated PointMeshes have two new display styles “Color from height” and “Color from photo overlap”. These ‘false color’ textures provide useful visual feedback.

Auto-assign control/EGE. A new tool automatically assigns control, pinned and multi-point transform points to associated points in the project. Points can be assigned by matching user name or point IDs.

Large Project UI Speed Improvements. Improvements in the speed of various user interface operations – noticable with large Smart Point projects.

User Interface Updates. New tool icons in the modern ‘flat’ style and new realistic Camera symbol in the 3d Viewer.

In addition, there are 126 fixes and improvements.

Getting the New Release

If you are a current customer and have an active maintenance subscription, get the update.

If you are new to PhotoModeler and would like to evaluate the new version, download it. You will have 10 days of full capability (load your own photos, export models, etc.). After 10 days it switches to a restricted Demo mode – and extension codes are available from PhotoModeler resellers.

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Tip 86: Reusing camera positions with replaced images http://info.photomodeler.com/blog/tip-86-reusing-camera-positions-with-replaced-images/ Wed, 30 Sep 2015 16:49:43 +0000 http://info.photomodeler.com/?p=1654 ...Read More]]> When two or more cameras, affixed in un-moving positions, are used in a project, the images taken by these cameras can be replaced in the project without having to re-orient them. Doing this can save time and effort for project setups or camera rigs that are reused repeatedly.rig

This procedure of swapping images on fixed cameras is useful for…

  • setting up repeatable measurement projects using a fixed multi-camera rig as shown at right,
  • doing comparisons between data sets while minimizing variables,
  • measuring movement over time from a set of fixed cameras positions (e.g. security cameras), and
  • creating multiple photo textures where lighting is variable.

These projects can be oriented with SmartMatch, Coded Targets or manually marked and referenced points. The first object of interest would then be modeled, and the results analyzed. Then the photos would be replaced with new ones showing a new object/scene, or with the object/scene in a new state.

To replace the photos, the “Replace photo (retain orientation)” hyperlink on the Photo clickProperties dialog is clicked for each photo and the new image taken by the appropriate camera is selected.

As soon as the photos have been replaced in the project, new points can be marked and referenced (or coded targets detected) on the new photos. The points appear in 3D and can be measured.  As well, the same process can be used to generate photo textures from a new set of photos (with different lighting for example).  The first project can be considered to be a ‘template’ for re-use with different images as needed.

Watch the YouTube video for an overview:

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The New PhotoModeler Ambassador and Grant Programs http://info.photomodeler.com/blog/the-new-photomodeler-ambassador-and-grant-programs-2/ Mon, 21 Sep 2015 19:50:52 +0000 http://info.photomodeler.com/?p=1649 ...Read More]]> Eos Systems is introducing two new community programs: PhotoModeler Ambassadors and PhotoModeler Grants.

PhotoModeler Ambassadors

Sharing IdeasA PhotoModeler Ambassador is a keen member of the PhotoModeler community that regularly uses PhotoModeler and photogrammetric processes in their work, and regularly shares information, using various media, about their experiences with colleagues and the community. Ambassadors receive recognition in a number of ways, including being listed on the PhotoModeler Ambassador web page: www.photomodeler.com/ambassadors.

PhotoModeler Grants

ResearchA PhotoModeler Grant is a discount on PhotoModeler software and maintenance for educational institutions and students (as well as the occasional indie film or game producer). To obtain the grant the student / professor / producer submits a grant application. Eos staff will review these applications on a case-by-case basis and within a week will inform the applicant of the discount amount. The discounts range from 20% to 100% of the software and maintenance purchase price. The Grant program provides the world-renowned PhotoModeler photogrammetry software, which is capable of solving many interesting tasks in academia and research, at a reasonable price and within the tight budgets that researchers, academics, NGOs, and indie film or game producers often find themselves.

View the press release announcing the two new programs.

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Tip 85: Measuring suspect height using a single photo from an unknown camera http://info.photomodeler.com/blog/measuring-suspect-height-using-a-single-photo-from-an-unknown-camera/ Tue, 01 Sep 2015 23:22:53 +0000 http://info.photomodeler.com/?p=1609 ...Read More]]> Surveillance cameras are ubiquitous in public places. Crimes and/or the suspects suspectbwparticipating in them are often captured on one or more of these cameras.

Measuring the height of a suspect in a scene is usually a key piece of evidence in identifying the individual. PhotoModeler can be used to accurately measure the height of a suspect in a single image from an unknown camera.

The example shown in this tip is a simulation of a crime scene where the suspect’s height needs to be measured.

Since the source of the image is unknown, PhotoModeler needs to ‘solve’ the camera’s parameters (e.g. focal length), using some known information about the scene. In PhotoModeler, this is called the “Inverse Camera” feature.

The investigator in this simulation first returned to the scene of the crime and surveyed a few points that had not changed since the day of the crime. He used PhotoModeler to do this using multiple photos from a calibrated camera, where he marked and referenced a few points in the office space to build up a model of the scene.  Any survey tool can be used to generate these points. The surveyed points become the “control points’ imported into the single-photo PhotoModeler project showing the suspects.

The “Manual Modeling” project was started (See “Getting Started” panel in PhotoModeler), the single photo loaded into the project, and the ‘Unknown camera solved by Control Points’ option for the camera was selected. ui

The control points created previously by the investigator were imported into the project, and marked on the photo in the appropriate locations (on features that hadn’t changed) using “Control Point Marking Mode” from the “External Geometry Explorer”.

A surface was modeled on the floor of the scene and “Surface Draw” feetpoints were used to mark the location where the suspect’s feet met the floor, and the location of other relevant items.

Next, “Z axis Offset Points” were added to the surface draw points height(offsets are created in the “Properties” of the selected surface draw points) at the base of the female’s feet. The offset distance property is adjusted until the displayed projected offset point meets the top of the head. Using this technique, her measured height was 63.5 inches (her known height was 63 inches). The steps are repeated for the male in the image (who appears to be slouching somewhat), and the measurement came out to 71 inches (his known height was 72 inches).

This tip is closely based on this Knowledge Base article which outlines this and two other approaches to measuring suspects’ heights.  These approaches can be used to measure the dimensions of any object in a photo – it does not only apply to criminals!

PhotoModeler has been successfully used in a wide variety of investigations and court cases, where the obtained measurement data was a critical component.

See these pages for other examples:

Watch the YouTube video for an overview:

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Tip 84: Preconfigured Layers and Materials in New Projects http://info.photomodeler.com/blog/preconfigured-layers-and-materials-in-new-projects/ Wed, 29 Jul 2015 17:22:55 +0000 http://info.photomodeler.com/?p=1554 ...Read More]]> Do you find yourself adding the same layers and/or materials to each of your new PhotoModeler projects? LayMatOr do you need a way to organize most of your PhotoModeler projects the same way – so that you can more easily separate or group items and display them in isolation? If yes, or if you don’t already know about Materials and Layers and their ‘profiles’ then this tip will be of interest to you.

Layers and Materials can be manually added to a project easily, but pre-configured layers and materials can be added to all new projects, automatically!

First, some background on layers and materials:

  • Layers:  Much like ‘layers’ in other CAD and graphics software packages, PhotoModeler Layers provide a means to separate or group model objects. Layers are used to control visibility of items in photos and the 3D Viewer, and can be used in Export. All projects by default have a ‘Default’ layer. Layers can be manually added to a project using the Layers dialog box, accessed by clicking the Layer tool:layers
  • Materials:  A ‘material’ defines what a model item will look like in the 3D Viewer or when exported. A material can be used to color or shade an item or give it a photo texture. All projects by default have a “Surface Default” material for surfaces and meshes, and a “White” material for other items. Materials can be manually added to a project using the Materials dialog box, accessed by clicking the Materials tool: materials

A set of pre-configured layers and materials can be added to each new project, by defining ‘profiles’ in the PhotoModeler configuration file. The process is fully explained in the Help document (press F1 in PhotoModeler, or use the Help menu, and search for “Material and Layer Profiles”). The Help section also describes how to open and edit the “PhotoModeler.ini” configuration file and add the settings to it, showing an example set of profiles.

The PhotoModeler.ini file is located in a subfolder of the AppData folder, similar to this (replace ‘name’ with your Windows account name):

path

Material and Layer profiles can be added to the bottom of the file.  Sample profiles look like this:


[MaterialsProfile]
NumMaterials=2
Material1=Blue
Material1Type=1
Material1TypeParam=000000255
Material2=SinglePhotoTexture1
Material2Type=2
Material2TypeParam=1

[LayersProfile]
NumLayers=2
Layer1=Hidden
Layer2=FrontSection

Once the project has the required layers and materials, it is simply a matter of selecting the item(s), and assigning the them to the layer or material, using the Layer and Material drop down tools next to their control buttons. AddToLayerTo add an item(s) to the ‘Hidden’ layer, select the item(s) in a photo, 3D Viewer or table, then select the ‘Hidden’ layer on the Layers drop down tool as shown at right.

The visibility of the assigned layer can be set using the Layer visibility controls. The example below shows the Layers control on the Visibility on Photos pane – items assigned to the ‘Hidden’ layer will not be displayed on photos, i.e. their 2D ‘mark’ locations, nor their 3D ‘projections’. LayerVisThere are similar controls on the 3D Viewer Options dialog (or the settings fly-out control at the left edge of viewer), and Export, as shown at right.

To assign the ‘Blue’ material to an item(s), select the item(s) in a photo, 3D Viewer or table, then select the ‘Blue’ material on the AddToMaterialMaterials drop down tool.

Note that once the layer or material has been assigned to an item, the drop down tools will show the item’s layer and material when the item is selected.

Using layers and materials can help organize a PhotoModeler project, especially when it starts getting complex, and is a useful method to visually differentiate items in photos, the 3D Viewer, and with Export.

Also see this related tip.

Watch the YouTube video for an overview on the use of pre-configured material and layer profiles:

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