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  • Special 4-hour Hand-on workshop: Making a Better Impression

Special 4-hour Hand-on workshop: Making a Better Impression

  • 01 Oct 2020
  • 1:00 PM - 5:00 PM


  • For members of Parent IAI and other divisions of IAI. Please contact EU IAI for discounted code at wuteresa@gmail.com

Registration is closed

Special Hand-on Workshop: Making a Better Impression (4 hours)

The forensic science community has had countless discussions about “sufficiency” as it relates to image quality (resolution), especially in terms of latent prints.  Is 1000 PPI enough, or is 1200 PPI better?  What about 1800 PPI?  Is 2400 PPI too much?  Should I capture 8-bit grayscale, 16-bit grayscale, 24-bit color or 48-bit color? 

What does “bit depth” and “resolution” mean when the monitor can only display a limited number of colors with a limited resolution.  Do I really need the extra bit depth since the dynamic range (the ratio between dark and light values) of digital imaging devices far exceed the range of human vision?

The bottom line is that if you understand the basic concepts and guidelines, you can apply the technology to make a better impression.  This workshop will focus on “resolution sufficiency” and how you can use that data to optimize image quality when processing digital evidence.

You will also be able to explain how the tools and techniques are used for processing digital evidence and how those processes aid in analysis, comparison, and evaluation. 

Update: The Forensic Digital Imaging and Analysis course, sponsored by the European Division of the IAI, named “Make a Better Impression,”  has been approved for 4 hours credit toward IAI Latent Print Certification and Recertification. Instructor credits are also approved for these courses.

Workshop Objectives:  After completing this workshop, participants will have a more comprehensive working knowledge of Adobe® Photoshop® CC.  Participants will understand the advanced procedures used in forensic digital imaging, such as working with multiple layers, creating overlays and more.  This is a “hands-on” training program, which includes “practical application” exercises to ensure the required learning objectives are achieved.

The following is a brief outline of the topics that will be taught in this four-hour training program. 

1) Review of Adobe Photoshop Preferences

2) Resolution Review:

  • Image (file) resolution versus display resolution versus output resolution
  • Refresher:  Calibrating images for 1:1 output

3) Suppress Background Noise with Color

4) Image Processing Techniques and Tools

  • Selecting “area(s) of interest”
  • Creating contrast: LevelsCurvesShadows/HighlightsApply ImageCalculation

5) Merging Channels and Layers

6) Sharing Images

Notes:  Participants will be expected to complete a final exercise that will be send to David Witzke for review and evaluation.  A certificate of completion will be provided with the evaluated image. 

For maximum effectiveness, participants should use a workstation equipped with two monitors.  One monitor will be used for participation in the workshop.  The second monitor will be used for simultaneous hands-on involvement of the instructor-led exercises using Adobe® Photoshop® CC.

System Requirements:

The minimum acceptable system requirements running Adobe Photoshop CC are:


Intel® or AMD processor with 64-bit support; 2 GHz or faster processor

Operating system

Microsoft Windows 7 with Service Pack 1 (64-bit), or
Microsoft Windows 10 October 2018 update (64-bit) version 1809 or later


2 GB or more of RAM (8 GB recommended)

Graphics card

nVidia GeForce GTX 1050 or equivalent; nVidia GeForce GTX 1660 or Quadro T1000 is recommended

Hard disk space

3.1 GB or more of available hard-disk space for 64-bit installation; additional free space required during installation (cannot install on a volume that uses a case-sensitive file system)

Monitor resolution

1280 x 800 display with 16-bit color and 512 MB or more of dedicated VRAM;
2 GB is recommended


OpenGL 2.0-capable system


An internet connection, Adobe ID, and acceptance of license agreement are required for activation of the trial version as well as the licensed version for validation of subscriptions

NOTE:  A free trial version of Adobe Photoshop CC can be downloaded from:


An internet connection and registration are necessary for required validation of trial subscriptions.  Adobe Systems has reduced the trial period for Adobe Photoshop CC from 30 days to only 7 days.  Participants should not install the trial version until one or two days before the start of the workshop.


David Witzke (aka Ski)


David Witzke, better known as “Ski” and was formerly Vice President of Program Management for Foray Technologies, has more than 30 years of AFIS and forensic digital imaging experience, and he is one of the most renowned experts in the field of digital processing of forensic evidentiary photography.

During the past 30 years, David has conducted hundreds of forensic digital imaging training programs for law enforcement agencies at all levels – local, State and Federal – throughout the United States, Canada, and Europe.  These training programs have been provided to novice, intermediate and advanced users in a variety of forensic disciplines including, but not limited to latent print examiners, footwear, and tire tread examiners, questioned document examiners and trace evidence examiners.

From 1998 to 2006, David became most well-known for his role as an associate instructor of the Digital Processing of Evidentiary Photography training program sponsored by the Federal Bureau of Investigation (FBI) Academy at Quantico, Virginia.  David also developed and taught the Forensic Digital Image Processing training program at the British Columbia Institute of Technology (BCIT) in Vancouver, BC from 1999 - 2005.  (The training program at BCIT was accepted as the foundation of the forensic digital imaging training program that is still being taught at the Royal Canadian Mounted Police (RCMP) police training facility in Ottawa, Ontario, Canada.)

From 2016 to 2018, David was also an adjunct professor for the Department of Forensic Sciences at George Washington University (GWU) in Washington, DC, where he developed and taught the Department’s first Digital Image Processing course (ForS 6129).  This course was a requisite for the Master of Forensic Sciences degree.

David has been a guest speaker and instructor at the European Network of Forensic Science Institutes (ENFSI) Fingerprint Working Group Meetings in Split, Croatia; Taormina, Italy; Barcelona, Spain; Pontoise, France; Lausanne, Switzerland; and Porto, Portugal.  David also conducted several digital image processing programs for the Automatic Fingerprint Recognition systems (AFR) Consortium throughout the United Kingdom as well as taught classes for the Federal Department of Justice and Police AFIS/DNA Services in Berne, Switzerland and the National Forensic Center in Linköping, Sweden. 

David has also developed and taught specialized digital imaging programs for the American Society of Questioned Document Examiners (ASQDE), the Scientific Association of Forensic Examiners (SAFE), and the International Association of Document Examiners (IADE). 

In December 2019, David was the keynote speaker on “Authenticating Documents in a Digital World” at the annual seminar sponsored by the Jamaica Institute of Financial Services (JIFS) in Kingston, Jamaica.

David is a contributing writer for three well-known books:

  • Crime Scene Photography (First, Second and Third Editions; the Third Edition was published in 2016 by Academic Press)
  • Introduction to Crime Scene Photography (Published 2012 by Academic Press)
  • Footwear, The Missed Evidence (Second and Third Editions; the Third Edition was published in 2013 by Staggs Publishing).

A fourth book, Forensic Photography for the Preservation of Evidence, is currently with the publishing company, Taylor & Francis/CRC Press, and will be released in 2020.

In addition, Crime Scene Photography is used by the discipline certification committees of the International Association for Identification for the Certified Crime Scene Investigator (CCSI) Certification Test, the Certified Crime Scene Analyst (CCSA) Certification Test, the Certified Senior Crime Scene Analyst (CSCSA) Certification Test, and the Forensic Photography Certification Test. 

The European Division of the International Association for Identification

Laan van Ypenburg 6

2497 GB, Den Haag

The Netherlands

Email: treasurer@theiaieu.org

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