understanding forensic digital imaging

[...]... was digital Any problems that have arisen involved the processing of the image and the conclusions drawn from them These issues are addressed in Chapter 20 FILM VERSUS DIGITAL PHOTOGRAPHY With film photography, the film that is in the camera is sensitive to light over its entire surface The light coming through the lens impinges on that surface 9 10 CHAPTER 1: Introduction to Forensic Use of Digital Imaging. .. using a different color set The lower image is not interpretable 7 8 CHAPTER 1: Introduction to Forensic Use of Digital Imaging steps to the process and they are quite complex In later chapters the most commonly used of these will be described An archival record of the image is an important product of a forensic photographic system A faithful reproduction of the input must be available for some time... photos will be needed, and it must be possible for viewers of the images to make the connections among the various shots If the images will be used for making 3 4 CHAPTER 1: Introduction to Forensic Use of Digital Imaging measurements, great care must be taken to ensure that the intended measurements will be valid The particulars will vary with the anticipated analytical purposes In many instances, special... phenomenon; it is just that the new digital technology has made it much easier to do The ability to detect manipulated images is a skill that is still in demand, however when the changes are made by an expert, recognizing these altered images is very hard to do Since the mid-1990s the issue of acceptance of digital images has grown in importance The obvious concern is that digital images are easily manipulated... the human eye are shown normalized to the areas under the curves being equal to one The sensitivity of the rods is shown with its peak sensitivity set to one 5 6 CHAPTER 1: Introduction to Forensic Use of Digital Imaging A photographic system must be able to respond to scene coloration so that it captures information in a way that can be used to construct an image with proper colorization so that a... of digital photography as distinct from film-based photography, but that separation is unrealistic In 2000, Dr Robert Davis, a consultant 4 The Federal Rules of Evidence have been interpreted also to call all prints made from the negative “originals” as well Not good science, but legal Film versus Digital Photography and educator in Dallas, Texas, demonstrated to the SWGIT that with highquality digital. .. original image? 2 What are the three main reasons for taking photos, and how does each fit into forensic photography applications? 3 Describe film and digital image originals in terms of their physical condition 4 What was the enabling technological change that made photography practical for crime scene photography? 5 Digital photography was able to achieve good quality images as far back as the 1980s in space... military applications It did not begin to achieve real adoption in law enforcement until the 1990s What are some of the factors that could have caused the delay? 11 12 CHAPTER 1: Introduction to Forensic Use of Digital Imaging 6 In order for a photographic system to serve as a useful surrogate, it must be able to successfully accomplish three functions What are those functions? 7 What are the functions of... coated in a factory and then the images were processed in a central laboratory long after the exposures were made Some History of Forensic Photography When this happened, it became practical to take photos at crime scenes As photographic technology advanced, its use in forensic applications expanded as well For example, photographers learned how to use contrast-enhancing filters and how to take photos... today’s world, the technology used to capture an image or the medium on which an image resides is no guarantee, all by itself, as to the legitimacy of the image Any image can be altered Practitioners of forensic imaging must take care in their processes to ensure legitimacy In a private conversation with a former governor of Indiana (Robert Orr), Randall Shepard, Chief Justice of the Indiana Supreme Court, . individuals to be better edu- cated about the science of forensic imaging and the preparation necessary to offer testimony concerning forensic imaging in a legal context. It is impor- tant to fi rst. through the lens impinges on that surface Some History of Forensic Photography CHAPTER 1: Introduction to Forensic Use of Digital Imaging 10 and activates silver halide crystals in the sensitive. the factors that could have caused the delay? Film versus Digital Photography CHAPTER 1: Introduction to Forensic Use of Digital Imaging 12 6 In order for a photographic system to serve