Choosing a Digital Image Management System
Written by Steve Scarborough, B.S., CLPE   

Image courtesy of Foray Technologies

One significant challenge for law enforcement today is the management of digital images. Many agencies have already made a full conversion to digital and many more have at least some units using digital cameras. That multitude of scattered photos (images) on CDs and various drives must be organized into a workable solution. The solution is a digital image management system. The future extension of that system is a digital image case management system.

The decisions for law enforcement today are not based so much upon the transition from film to digital (as they were a few of years ago) but instead involve the best options to manage all these digital images. However, even if the decision is made to moderate the transition in segments—beginning with an image repository, for example—it is important to obtain a system that allows for later expansion. That expansion may eventually lead to an enterprise system that spreads asset management throughout the agency or department and provides service to multiple sections.

It is vital that the system software ultimately procured has the capability to expand beyond a digital image management system to a full enterprise asset management system for the future.

Therefore, evaluating and procuring just the right digital image management system for your agency is crucial. The decision-making process is now more important than ever, and thinking ahead is critical. It is imperative to make the correct decisions early
to avoid the pitfalls later on.

During the evaluation process, it is important to choose a forensic digital imaging system that is the best fit for your agency and the goals of your department. Evaluate imaging systems that are designed specifically for law enforcement and adaptable and customizable for the uniqueness of a law enforcement setting.

Progressive technology has made the leap from a basic digital image management system—designed to secure, store and retrieve digital images—to a comprehensive enterprise information system that provides access to multiple users and units over a network, and storage and access to the data associated with the images. Most image management systems can be networked, but the best systems will be designed for universal access and an electronic workflow. These systems give every user the power to retrieve and analyze digital assets on the network and collaborate with other users.

A forensic digital image management system and systems designed for photographers, advertising, or graphic design are very different. An agency should look for a system that goes beyond the basic system functions such as maintaining image security, ensuring consistency in file naming protocols, and controlling access to the images. Systems designed for a forensic or law enforcement environment are cognizant of the important forensic issues such as enhanced security, extensive documentation features, and interface to other systems. Recognize that for those reasons, a system designed for a forensic setting is packed with a lot more technology than one designed only as an image repository.

Security

Enhanced security, such as a user- or role-based security system, is very important for a digital image management system for law enforcement. Role-based security restricts access to the image folders and files based upon their classification or unit. That means that a supervisor can be given more access to files, or specific units can access only those files they are assigned. The crime scene section may only have access to scene photos, but the case detective may have access to all case images, and so on. Highly sensitive files, such as those involved in a sexual assault or an internal affairs investigation, can be restricted to specific individuals. The best systems will also have the ability to narrow down this access to specific categories, such as view and print. The ability to expand a system to accommodate many users and the ability to turn on and off this access is important.

The image management system should also have an image authentication process and an image audit/ history tracking procedure. Image authentication is an important feature that verifies that the image brought into the system has remained unaltered. History tracking follows the image throughout the system, records any changes to the image and may even record the basic viewing of the image by a user. History tracking helps establish image integrity (in digital imaging it is image integrity, not chain-of-custody) and should provide history tracking reports for court preparation. A first-rate forensic image management system will meet all of the suggested requirements of ISO, ASCLD, and SWIGIT.

Make sure your system automatically saves original files in their original formats—automatically being the key word here. One of the first lessons in an image enhancement training course is the process of saving your images and then working on copies. You don’t want your operators or experts to even think about this process; have your image management system do it automatically.

Documentation

Some aspects of security and documentation should overlap on an image management system designed for police agencies. A good system will be able to document an analysis of the images by printing reports, and incorporating the authentication and history tracking process. In addition, and in response to recent increased scrutiny of the forensic sciences, some forensic image management systems will allow data to be appended to the image file, increasing and improving the documentation process. This data can then be integrated into case notes and reports, automatically creating case notes, image documentation, and reports from stored data.

The preferred method for maintaining this data and storing images is through a database. A database is very important. A database allows for the processes mentioned above, as well as searching and data analytics. A system that uses common database engines such as SQL or Oracle, giving the IT section ultimate access, is best.

Another aspect of a database is the ability to locate your images in the system using data attached, or tagged, to the image. The ability to attach information beyond crime types, locations, and subjects—even to very specific aspects of the crime—can be very valuable.

This data can then be “mined” or searched for information, providing collaboration between units and even agencies.

Case Management

The progression to a case management system from an image management system includes the process of information tracking and the capability of producing multiple types of reports. Case management covers the entire process from acquisition, image management, report production, and data analysis. The best systems will have a predesigned forensic workflow to incorporate all of these processes.

Procurement Paths

A caution about two alternative paths for obtaining a forensic digital imaging system: One substitute path for obtaining a system would be one assembled in-house using available software products. Typically a do-it-yourself (DIY) system is gathered “piecemeal”, putting together various products: asset management software, image processing software, and word-processing or documentation software. These DIY systems, whether created by agency IT or in-house experts, are not flexible enough to combine all the tasks necessary into a smooth workflow.

Another course for procuring a system is to limit the search to so-called “tier-one”, or major company, software. While tier-one programs will have a large base and big-company support, they will not typically have the focused features needed to set up a secure but flexible forensic imaging system. This is because there are no tier-one systems designed for forensics or law enforcement. Most of these systems are document or blob (binary large object) management systems. Since they can handle the imaging of documents or blobs, the companies reason that they can handle any digital image.

However, settling for a tier-one product—a large off-the-shelf asset manager that is not specifically designed for law enforcement—could be a mistake for a police agency. These programs are very valuable in the area in which they were originally designed and intended; however, they will not provide a law enforcement agency with all of the necessary components for a forensic storage and analysis system. And certainly they will not take an agency into the future with a full enterprise system that expands into the forensic laboratory and throughout the agency.

A tier-one system may have the capability for storage and some form of security, but a lot of the forensic components such as role-based security, history tracking, enhancement tools, and on-screen comparison capabilities will have to be customized. A tier-one system will have to be adapted, most likely with other software products, to provide a method-documentation process, automatic case notes, and report generation.

Additionally, some systems, specifically those designed for photographers, are merely a repository for the many forms of digital images we have today. They may have a good security system in place but do not have an essential component: a secure database. A well-designed digital image database will complete the process and allow for all the advantages of a typical database: searching, method documentation, automatic reporting, and case analytics.

It is important to have the ability to customize the system to follow how various departments—photo lab, latents, evidence processing, DNA, and chemistry—individually work. The system should be able to be customized to work the way an agency does and not the way an imaging software company dictates.

An important consideration here: if that initial procurement is limited to an image repository (a photo-lab based system), future growth to a database system or expansion into other sections of the department is generally limited. A supplemental system is usually needed for that type of expansion. The best system will be expandable and adaptable to the future forensic demands that may arise.

Of course, the system acquired should handle all types of file formats. Some image management systems, and many DIY systems or tier-one systems, cannot handle all the various types of images required by a law enforcement agency. All image management systems will handle JPEGs, but your system should have the ability to handle TIFF, video, audio files, and even PDF files. The system should also have the ability to convert RAW files, though for many reasons RAW processing should be limited (see sidebar: “A little about RAW files and forensic imaging”).

Summary

  • Acquire a system designed for forensics and law enforcement.
  • Consider a full case management system that includes digital image management
  • Procure a system that works on your existing hardware, especially as an option in a limited funding environment.
  • The power of a database comes only with a database system. Look for a system that includes a secure database in order to have the full capabilities of a database.
  • The best systems will have advanced security to limit access to images, right down to the files.
  • Purchase a software product with the ability to add extensive data (beyond just metadata) to the images to allow for automatic preparation of case notes and reports.
  • Locate a forensic digital imaging system that has the ability to customize the system to follow how an agency works.
  • Do the research to find a software system that was designed for universal access for all users.
  • Make sure your system has the capability to expand beyond a digital image management system to a full enterprise asset management system with case management.

Conclusion

It is imperative to get control of your agency’s digital images. The key is following a comprehensive plan to find the best forensic digital imaging system for law enforcement.

If there is particular emphasis in a specific discipline, make sure the system you procure can also deal with that discipline. For example, the main sections using mass amounts of digital images—especially when converting to an electronic workflow—are the comparative analysis sections such as the latent print unit. Find a system that is versatile and also provides a workflow and latent case management process, either as a main component or an upgrade. This will prevent any problems integrating multiple pieces of disparate software into one system. In addition to image file management, a case management process and workflow can provide extensive documentation and reporting.

A good digital image management software package will automate the input, storage, and retrieval of digital images, assuring system integrity; and will also provide the capability for advanced imaging processes. The best digital image management system will include a full case management system. This system will incorporate image enhancement, case documentation, report generation, data analysis, and the capacity for intra-unit and interagency collaboration, creating a multi-dimensional or a full-enterprise system installation.


Sidebar:
A little about RAW files and forensic imaging

Due to prevailing opinion, RAW files seem to be tailor-made for forensics and law enforcement. However, this issue should be examined closely to understand RAW files and to prevent a forensic imaging system from becoming bogged down due to the time and man-hours necessary to process RAW files. The value of RAW for forensics may be somewhat overestimated.

A RAW file is a data file of information and is not a photo until it is processed. RAW files are not image files like a JPEG or TIFF. Actually, the JPEG image produced by your camera came from the RAW sensor data in the camera and was automatically converted to an image file.

Unfortunately, there is no standard RAW file; they are nonstandard proprietary formats that vary between manufacturers and even within camera lines. There is also no standard for RAW files within the industry. This is important for forensics because it is not known if these files will be accessible from the archive five or ten years down the road. In the forensic community, it is often important for images to be kept for decades.

Normally, crime scene and lab analysts save RAW files and archive them, but view the JPEGs and work with those for crime scene documentation. JPEGs are accepted as an adequate format for crime scene and evidence documentation. Lossy compression formats can be used for documentation purposes, and lossless formats, such as TIFF, can be used for images intended for analytical purposes.

There has been debate in the forensic community about the best formats for evidence purposes, and some state that since a RAW file is an image in its purest form, it is essentially a digital negative. This is not true. The RAW file is not a universally viewable image. It is a string of unprocessed data from the pixels in the camera. For all the reasons stated in this article, a RAW file is not a digital negative.

The value in a RAW file is in the ability to pre-process the image to obtain the best exposure, color balance, etc. That’s exposure, not quality. There is no quality value or higher resolution value inherent in a RAW file.

The processing of a RAW image to adjust exposure and color using a processing program takes time and training. In a forensic or police setting, this processing takes up valuable man-hours and requires additional training. A workflow that calls for processing all RAW files is just not practical or fiscally responsible in a law enforcement environment.

If a law enforcement agency decides to capture photos using the RAW setting, the best forensic workflow would be to take RAW files for all comparative analysis and highly sensitive photos, and take JPEG for all other purposes such as location and demonstrative photos.

A standard forensic workflow for the RAW images would be to convert all of the RAW files to TIFF images and save the RAW and original TIFF files within the system. Use those high-quality TIFF images within the normal course of analysis. Then, if necessary—and only if necessary—retrieve the RAW files and process them within a RAW file program.

While RAW files can be valuable in forensics, they should be used in a measured and limited process—in special circumstances—to preserve an efficient and cost-effective forensic photographic system.


About the Author

Steve Scarborough, B.S., CLPE, LVMPD Forensic Scientist (retired), is an independent biometric consultant and SME consultant for Mideo Systems. He retired as a forensic scientist with more than 35 years experience in law enforcement with the Las Vegas Metropolitan Police Department (LVMPD) and the FBI. While with LVMPD, he designed an innovative, one-of-a-kind AFIS system, and brought digital imaging to LVMPD in 1998. He has written almost 30 articles in forensic journals and trade magazines and frequently trains and lectures at forensic conferences. He has been recognized by Interpol in Review Papers at the 14th International Forensic Science Symposium in Lyon, France for his contribution to forensic digital imaging.

 
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