OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

1

OSAC 2021-S-0037 Standard 

Guide for Forensic 

Photogrammetry

Video/Imaging Technology Analysis Subcommittee

Digital/Multimedia Scientific Area Committee (SAC)

Organization of Scientific Area Committees (OSAC) for Forensic Science
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

2

OSAC Proposed Standard

OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

Prepared by 

Video/Imaging Technology Analysis Subcommittee

Version: 2.0 - OSAC Registry

April 2023

Disclaimer:

This OSAC Proposed Standard was written by the Organization of Scientific Area Committees 

(OSAC) for Forensic Science following a process that includes an open comment period. This 

Proposed Standard will be submitted to a standards developing organization and is subject to 

change. 

There may be references in an OSAC Proposed Standard to other publications under 

development by OSAC. The information in the Proposed Standard, and underlying concepts and 

methodologies, may be used by the forensic-science community before the completion of such 

companion publications.

Any identification of commercial equipment, instruments, or materials in the Proposed Standard 

is not a recommendation or endorsement by the U.S. Government and does not imply that the 

equipment, instruments, or materials are necessarily the best available for the purpose.

To be placed on the OSAC Registry, certain types of standards first must be reviewed by a 

Scientific and Technical Review (STR). The STR process is vital to OSAC’s mission of 

generating and recognizing scientifically sound standards for producing and interpreting forensic 

science results. The STR shall provide critical and knowledgeable reviews of draft standards or 

of proposed revisions of standards previously published by standards developing organizations 

(SDOs) to ensure that the published methods that practitioners employ are scientifically valid, 

and the resulting claims are trustworthy.

The STR will consist of an independent and diverse panel, including subject matter experts, 

human factors scientists, quality assurance personnel, and legal experts, which will be tasked 

with evaluating the proposed standard based on a comprehensive list of science-based criteria.
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

3

For more information about this important process, please visit our website 

at: https://www.nist.gov/topics/organization-scientific-area-committees-forensicscience/scientific-technical-review-panels.
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

4

Designation: 2021-S-0037 

1. Scope 

1.1 This standard provides basic information on conducting photogrammetric examinations as 

a part of forensic analysis. The intended audience is examiners in a laboratory and/or field 

setting. 

1.2 This standard is not intended to be used as a step-by-step practice for conducting a proper 

forensic examination or reaching a result. This document should not be construed as legal advice. 

1.3 This standard cannot replace knowledge, skills, or abilities acquired through education, 

training, and experience, and is to be used in conjunction with professional judgment by 

individuals with such discipline-specific knowledge, skills, and abilities.

1.4 This standard does not purport to address all the safety concerns, if any, associated with its 

use. It is the responsibility of the user of this standard to establish appropriate safety and health 

practices and determine the applicability of regulatory limitations prior to use. 

2. Referenced Documents 

2.1 ASTM Standards: 

2.1.1 E2825 Standard Guide for Forensic Digital Image Processing 

2.2 SWGIT Material: 

2.2.1 SWGIT, Section 13: Best Practices for Maintaining the Integrity of Digital Images and 

Digital Video, updated January 13, 2012 

2.2.2 SWGIT, Section 11: Best Practices for Documenting Image Enhancement, updated 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

5

January 15, 2010 

2.3 SWGDE Material: 

2.3.1 SWGDE Training Guidelines for Video Analysis, Image Analysis, and Photography, 

updated February 8, 2016 

2.3.2 SWGDE Best Practices for the Forensic Use of Photogrammetry, 

updated September 29, 2015 

2.3.3 SWGDE Guidelines for Forensic Image Analysis, updated February 21, 2017 

2.4 Edelman, G., Alberink, I., and Hoogeboom, B., Comparison of the Performance of Two 

Methods for Height Estimation, Journal of Forensic Sciences, Vol 55, No 2, March 2010 

2.5 Hoogeboom, B. and Alberink, I., Measurement When Estimating the Velocity of an 

Allegedly Speeding Vehicle from Images, Journal of Forensic Sciences, Vol 55, No 5, 

September 2010 

2.6 Hoogeboom, B., Alberink, I., and Goos, M., Body Height Measurements in Images, 

Journal of Forensic Sciences, Vol 54, No 6, 2009 

2.7 Criminisi, et al., A New Approach to Obtain Height Measurements from Video, SPIE Vol 

3576, November 1998

3. Terminology 

3.1 Definitions: 

3.1.1 analytical photogrammetry, n-a method of photogrammetry in which solutions are 

obtained by mathematical methods 

3.1.2 reverse projection photogrammetry, n-a method of photogrammetry in which a measuring 

device is recorded within a scene and the resulting image is overlaid on the evidentiary image to 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

6

measure an object 

3.1.3 3D scanning, n-the process of capturing 3-dimensional representation of an object or scene 

with equipment that measures the distance between the scanner and the object to create a point 

cloud of data from the surfaces of the object or scene

3.1.4 photogrammetric analysis, n—process of obtaining dimensional information regarding 

objects and people depicted in an image. E2916

3.1.5 photogrammetry, n—the art, science, and technology of obtaining reliable information 

about physical objects and the environment through the processes of recording, measuring, and 

interpreting photographic images and patterns of electromagnetic radiant energy and other 

phenomena. E2916

4. Summary of Practice 

4.1 The original image or video shall be preserved. Any processing shall only be applied to a 

working copy of the image or video. 

4.2 The practice may include: 

4.2.1 Evaluating the imagery to determine the most suitable photogrammetric method 

4.2.2 Obtaining scene-based reference data 

4.2.3 Applying a photogrammetric process to obtain measurements 

4.2.4 Identifying and reporting sources of uncertainty and apply to the measurements

4.2.5 Reporting findings 

4.3 Steps taken and methods used shall be documented to permit a qualified practitioner to 

understand and be able to recreate the examination performed, as well as to assess and evaluate 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

7

the results reached. 

5. Significance and Use 

5.1 Photogrammetric analysis is a long-standing science that can aid in the exclusion and 

inclusion of items and people in forensic investigations. It can also answer specific questions 

regarding speed, size, location, and distance of objects, areas, etc. in the field of view.

5.2 This guide addresses the following three phases of photogrammetric examination: 

5.2.1 Evidence Preparation 

5.2.2 Methodology 

5.2.3 Interpretation of Results 

6. Evidence Preparation and Assessment 

6.1 Evidence preparation is any process intended to preserve and prepare an image for 

photogrammetric analysis. 

6.1.1 The original imagery shall be protected from any alteration. 

6.1.2 The examination shall be conducted on working copies of the imagery. Preparation of a 

working copy may require digitization or transcoding from other formats. 

6.2 Complete an initial assessment of the imagery

6.2.1 Determine if the submitted imagery is the best available evidence, such as the original 

media, or a bit-for-bit duplicate. If the submitted imagery is not a bit-for-bit duplicate, 

determine if one is available. For additional information on this topic, see SWGDE Guidelines 

for Forensic Image Analysis. 

6.2.2 Determine which subset of the submitted material is suitable for analysis. Suitability for 

analysis may vary by the examination requested. Criteria to be considered include whether: 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

8

6.2.2.1 The entire area, subject, or object to be measured is visible, 

6.2.2.2 The entire area, subject, or object is recorded at a sufficient native resolution to make a 

meaningful measurement, 

6.2.2.3 The angle of capture or camera perspective is conducive to examination, 

6.2.2.4 The position and orientation of the subject or object in the frame is affected by lens 

properties such as distortion. DOF and focal length,

6.2.2.5 The scene contains fixed objects/features which can be used as reference data. 

6.2.3 Determine if all the submitted material, or some subset of the material, is to be subjected 

to analysis. 

6.2.4 Observations, decisions, and opinions made during preparation and assessment shall be 

documented.

6.3 Process the working copy to enhance and/or restore the image content, if necessary. For 

further information, see ASTM E2825 Guidelines for Forensic Digital Image Processing.

7. Methodology 

7.1 Multiple techniques exist for performing photogrammetric analysis including reverse 

projection and analytical photogrammetry. This guide does not limit the use of other available 

methods. 

7.2 The examiner should consider both the evidentiary imagery and details of the scene to 

select the most suitable method for examination. 

7.3 The chosen methodology should be validated and have a scientific basis. 

7.4 Reverse projection photogrammetry -- involves the positioning of a camera to capture an 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

9

image in the same perspective and aspect ratio as the evidentiary imagery and using a 

calibrated measuring device to complete the requested analysis. 

7.4.1 The first step in the process is to assess the scene depicted in the evidentiary image.

7.4.1.1 Determine if the depicted scene is physically accessible.

7.4.1.2 Decide if the significant fixed objects and features in the depicted scene are still present 

at the scene and suitable as reference targets.

7.4.1.3 Determine the recording system that captured the evidentiary image is still in place, 

accessible, and suitable for the examination.

7.4.1.4 If still present, determine whether the original camera has been moved or changed.

7.4.2 The examination process includes the following steps:

7.4.2.1 Decide whether to use the original recording system, if available, or different 

recording equipment to collect new data.

7.4.2.2 Place the measuring device in the correct position and calibrate.

7.4.2.3 Measure from multiple device positions to mitigate measurement uncertainty.

7.5 Analytical photogrammetry – involves applying knowledge of the geometrical properties 

of the imaging process, and known measurements associated with the imagery, to obtain 

unknown measurements.

7.5.1 Perspective-based analysis and direct scaling are two approaches. When using an 

analytical photogrammetry method, the following issues should be considered and 

documented: 

7.5.1.1 Decide whether there are sufficient reference features available within the imagery to 

resolve the geometry of the scene, including three-dimensional axes, horizons and vanishing 

points. 

7.5.1.2 Measure the uncertainty derived from the angle of measurement, and the position of the 

subject. 

7.5.1.3 After performing the chosen methodology and documenting results determine whether 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

10

the data collected during the examination process is of sufficient quality to support further 

analysis. 

8. Interpretation of Results 

8.1 A series of observations and/or measurements recorded using the enacted methodology will 

require the examiner to interpret results. 

8.2 Measured results require interpretation by the examiner based on the identified sources of 

uncertainty (and potential error). Sources of measurement uncertainty may include limitations of 

the: 

8.2.1 Original and controlled capture systems (e.g. camera height and position will influence 

the geometric calculation of the measurement; image resolution will limit the precision of the 

measurement) 

8.2.2 Measuring device (e.g. accuracy of placement will influence the geometric calculation; 

precision of the scale will influence the uncertainty) 

8.2.3 Employed software and hardware (e.g. inherent software limitations will influence the 

precision, such as the calculation of vanishing points and the numerical precision of data types) 

8.2.4 Factors involving the original subject (e.g. posture, contrast, location, movement) For 

example, the individual frame of a subject selected for height analysis will affect results, as 

height will vary over time. The examiner can use the measured height, as well as calculated 

uncertainty, to determine whether a person of interest can be excluded from or included in the 

group of suspects based on the range of estimated height.

8.3 Based on the observations and measurements, a result should be reached. This may or may 

not be in the form of a numerical value. 

8.4 Report results in response to the requested analysis. The basis for, and uncertainty of, any 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

11

results shall be documented and reported. An examiner should consider factors that influence 

the uncertainty of measurement, including the limitations of the measured results. 

8.5 The results of the examination should undergo independent review by a qualified 

individual.

8.5.1 If disputes arise during review, a means for resolution of issues should be in place. 

8.5.2 Additionally, if the examiner and reviewer reach different opinions, then both opinions 

and how the inconsistency was resolved must be documented.

8.6 To reduce potentially biasing effects, an examiner should not be exposed to task-irrelevant 

contextual information, such as the measured height of a suspect. 

8.6.1 Any contextual information provided to the examiner shall be documented.

8.6.2 Similarly, a technical reviewer should not be exposed to task-irrelevant contextual 

information or to the examiner’s conclusions.

9. Guidelines for Photogrammetry Standard Operating Procedures 

9.1 The purpose of forensic photogrammetric analysis is to apply knowledge of image 

processing techniques, measurements, and analysis to answer specific questions, as discussed 

in Appendix 3. Regardless of the methodology employed, standard operating procedures 

should be developed and followed. For more information on developing an SOP, see the 

SWGDE/SWGIT document, “Recommended Guidelines for Developing Standard Operating 

Procedures”. For more information on image processing, see E2825. 

9.2 Equipment—The laboratory standard operating procedure (SOP) should define minimum 

hardware and software equipment requirements including, but not limited to:

9.2.1 Hardware 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

12

9.2.1.1 Input/capture device, 

9.2.1.2 Measuring device, 

9.2.1.3 Image-processing systems, 

9.2.1.4 Output devices, and 

9.2.1.5 Storage/archive. 

9.2.2 Software: 

9.2.2.1 Image management, and 

9.2.2.2 Image processing. 

9.3 Procedures—Laboratories should establish specific step-by-step procedures for forensic 

photogrammetry and image processing according to published guidelines. Each utilized 

methodology for photogrammetric analysis (including, but limited to, reverse projection, 

analytical photogrammetry, and dimensional scanning) should have separate procedures. These 

procedures should address the following as a minimum: 

9.3.1 Documentation, 

9.3.2 Capture, 

9.3.3 Image processing, 

9.3.4 Storage and archiving, 

9.3.5 Image management 

9.3.6 Data security 

9.3.7 Photogrammetric Methodology 

9.3.8 Interpretation of results, and 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

13

9.3.9 Reporting 

9.4 Calibration—Laboratories should develop SOPs for calibrating all equipment that produces 

test results. These procedures should be consistent with the manufacturer’s recommendations. 

9.5 Limitations—Laboratories should document the limitations of their processes and 

equipment in their SOPs. 

9.6 Safety—Laboratories should develop safety procedures specific to their needs. 

9.7 References—Laboratories should maintain their laboratory specific documentation, 

manufacturers’ manuals, and published guidelines.

9.8 Training—Laboratories should define the level of training necessary to perform the 

procedure. Refer to the SWGDE “Training Guidelines for Video Analysis, Image Analysis and 

Photography”. 

10. Keywords 

10.1 criminal justice system; image processing; digital image processing; forensic 

photogrammetry 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

14

APPENDIX 

(Nonmandatory Information) 

X1. APPENDIX 1: CONSIDERATIONS WHEN REPORTING THROUGH QUALITATIVE 

MEANS 

X.1.1 Purpose 

X1.1.1 This guide sets forth key points that should be considered when reporting quantitative 

photogrammetric analysis results. 

X.1.2 Estimation of error in analysis 

X1.2.1 Photogrammetric evaluation is amenable to estimation of error, either through the

propagation of error involved in the calculations, or in comparison with known measurements 

that may be present in an image. Both common kinds of error (imprecision and bias) should be 

estimated if possible, and if not possible, the limitations of the method should be documented 

in the final report. 

X1.2.2 Example: As in the workflow example, the practitioner is requested to complete a 

photogrammetric examination of a bank robber depicted in DCCTV surveillance video. The 

police have two different suspects and would like to determine if either can be eliminated 

based on height. 

X.1.3 Incorporation of uncertainty in reporting of results 

X1.3.1 The practitioner elects to use the recommended workflow for photogrammetry, 

incorporating reverse projection as the analytical method. Photogrammetric measurement 

estimates the height of the individual to be 6’1”. This measurement is based on the vertical 

distance from the floor to the top of the individual's headwear, in a single selected image.

X1.3.2 However, multiple areas of uncertainty can be calculated, and multiple limitations in 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

15

this measurement should be noted in the analytical report. 

X1.3.2.1 In photogrammetric examinations, the estimated uncertainty relies on the overall 

resolution of the imagery. When the number of pixels representing a given area (or a line of 

video) in an image increase, the practitioner will be able to narrow the uncertainty based on 

resolution. This uncertainty may need to be calculated at two points when completing two 

examinations, as in an analysis of the velocity of a subject. 

X1.3.2.2 In photogrammetric examinations, the estimated uncertainty relies on the ability of 

the practitioner to locate the position in which the subject was located at the time the original 

image was captured. This uncertainty can be calculated by determining the uncertainty in the 

measured distance within a given radius of position, based on geometric principles. 

X1.3.2.3 In subject height analysis, the measurement is captured at only a single moment of 

262 time. Given that multiple factors can change a subject’s stature, including choice of 

footwear, choice of headwear, positioning in gait, and the natural circadian rhythms of the 

human body, the measured height can be no more than an estimation. 

X1.3.2.4 In the case of a velocity analysis, the calculated value for velocity relies upon a 

known time interval, and the distance traveled by an object, between two images. The 

uncertainty in the calculated velocity should be examined based on principles of video 

engineering and image analysis and recognizing the errors in time and distance measurements. 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

16

APPENDIX 

(Nonmandatory Information) 

X2. APPENDIX 2: WORKFLOW EXAMPLES 

X.2.1 Scenario 1: 

X2.1.1 A local police agency asks the crime laboratory to determine the height of the 

individual depicted robbing a bank in a surveillance video, captured by a DCCTV system. The 

agency has two suspects of different heights and would like the crime laboratory to determine 

if either can be excluded on this basis. 

X2.1.2 The practitioner proceeds as follows, while documenting the process, analyses, and 

results: 

X2.1.2.1 The practitioner determines that the imagery is the original video, not a transcoded 

copy. 

X2.1.2.2 The practitioner reviews the material and determines if images exist suitable to an 

accurate photogrammetric examination. 

X2.1.2.3 The practitioner determines if more than one examination is appropriate to complete 

the request. 

X2.1.2.4 The practitioner transfers the contents of the video file to a working file. X2.1.2.5 The 

practitioner processes the video files. 

X2.1.2.5.1 Still images are output from the video files, and images suitable to an accurate 

photogrammetric analysis are selected. 

X2.1.2.5.2 Standard image processing techniques, such as brightness and contrast adjustments, 

are applied to the working images.
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

17

X2.1.2.6 The practitioner imports the images into an application suitable for photogrammetry 

and conducts the analysis. This analysis results in a calculated value for the robber’s height, as 

well as a determination of the accuracy and precision of this output. This step should be 

documented and the limits of the results obtained should be clearly identified. 

X2.1.2.7 The practitioner writes the report. Per the crime laboratory’s standard operating 

procedures, the report includes a review of the materials received, the request, the methods used, 

the observations noted, the basis for the interpretations, the results, and an estimate of the 

accuracy and precision. 

X2.1.2.8 The report is administratively and technically reviewed prior to release. X.2.2 

Scenario 2: 

X2.2.1 A local police agency asks the crime laboratory to determine the velocity of a vehicle, 

as it is driven toward impact. The vehicle is captured for approximately four seconds, just prior 

to collision. The agency would like to know the vehicle’s velocity as a possible aggravating 

factor in the investigation of the collision. 

X2.2.2 The practitioner proceeds as follows, while documenting the process, analyses, and 

results: 

X2.2.2.1 Determines that the imagery is the original video, not a transcoded copy. 

X2.2.2.2 Reviews the material and determines if images exist suitable to an accurate 

photogrammetric examination. 

X2.2.2.3 Determines if more than one examination is appropriate to complete the request; 

X2.2.2.4 Transfers the contents of the video file to a working file. 

X2.2.2.5 Processes the video files.

X2.2.2.5.1 Still images are output from the video files, and images suitable to an accurate 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

18

photogrammetric analysis are selected, considering the known time elapsed between the 

images. 

X2.2.2.5.2 Standard image processing techniques, such as brightness and contrast adjustments, 

are applied to the working images. 

X2.2.2.6 Imports the images into an application suitable for photogrammetry and conducts the 

analysis. This analysis results in a calculated value for the vehicle’s velocity, as well as a 

determination of the accuracy and precision of this output. 

X2.2.2.7 Writes the report. Per the crime laboratory’s standard operating procedures, the report 

includes a review of the materials received, the request, the methods used, the observations 

noted, results obtained, the basis for the interpretations, the results, and an estimate of the 

accuracy and precision. 

X2.2.3 The reviewer completes an administrative and technical review of the analysis and 

report. The technical review shall include verification of the results. 
OSAC 2021-S-0037 Standard Guide for 

Forensic Photogrammetry

19

X3. APPENDIX 3: SAMPLES QUESTIONS ASKED IN FORENSIC PHOTOGRAMMETRY 

X.3.1 How tall is the individual? 

X.3.2 How fast was the vehicle/person/object travelling? 

X.3.3 What time of day was the photograph taken? 

X.3.4 Where is the scene depicted in the image? 

X.3.5 What are the dimensions of an object? 

X.3.6 Where was the camera at the time this photograph was taken? 

X.3.7 Can you determine the location of the object(s) within the scene?