This blog is a collection of student comments on the concepts and questions that they are examining as they are introduced to forensic science.
Monday, March 9, 2009
Video Enhancement of Video Images
Often times, identification of suspects and perpetrators is accomplished by or in corroboration with video footage. The video footage usually analyzes many features of an individual, one very important feature being the face. The face is a key identifying tool for law enforcement. With it, a person can be matched with almost complete certainty to their facial image. However, video footage is not always easy to work with. Often times, cameras are out of focus, in bad condition, not functioning properly, in poor lighting, or simply of poor quality. This often poses major problems when trying to identify a suspect. When an image is enlarged, it becomes very pixelated, and cisual enhancement does only so much to improve this. Herein lies the problem of using video fotage. The solution: forensic sketch artists. A forensic sketch artist can easily reckognize facial features, and recreate them in a drawing. To replicate the still photograph with detail, a forensic artist can use the visible forehead contouring and bony structures, and selected full front facial features can be drawn in similar proportions. With a magnifying glass, fingerprint loop, or microscope, more detailed shapes, shadows, and images can be readily seen for the artist to replicate and place in proportion. Features such as a jawline (lower mandible) can break in a normal range or in an abnormal (or extreme) shape. When features are unclear or grayed in the image, the forensic artist knows to go the normal route, rather than guess, until further information can be obtained. Lighting and angle of a video camera are other aspects that can help or hinder in image capturing. A forensic artist can be an asset in recreating the facial image captured on videotape, as it is just one frame of a moving motion. Although the finished sketch is not always completely accurate to the individual's facial features, most of the time, enough resemblence is present to make a connection and pinpoint the individual as a suspect.
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6 comments:
I think this article was very interesting because it was nice to learn how exactly video footage is used in help solving crimes since it is very common that crimes are caught on tape. I didnt know that forensic sketch artists were involved in this also and it was interesting to learn about them. This was a very well constructed article nice job!
This is very interesting article about the importance of forensics scotch artist. David did a good job of explaining the detail of this technology of using different aspects of a suspects face to recreate an accurate image. Another thing that I thought was well presented was the way he mentioned the application of this technology to forensic science. The article thoroughly explains how the artist can use surveillance video from crime in order to further identify the perpetrator. Lastly, I liked the way the article was written, and organized. Some things that I might suggest to be improved, would be adding talking about the training needed for these forensic sketch artist, and if it is possible to have any existing field agents be trained to create these sketches. I think that it is very interesting how pixilated surveillance can be used to create a DNA profile. Overall this was a great review.
David, I really liked your opening sentences because they provided me with great background information regarding your topic. Also, I commend your usage of detail because it allowed me to be overwhelmed by the topic. Finally, I liked how you were able to show us how video enhancement will prove useful towards criminalists in the field of forensics. Maybe next time you could include a few names as to who thought of this idea, or better yet, a opinion from one of the forensic sketch artists regarding their opinion on the subject.
I am amazed that there are so many ways that video footage can be useless in a crime -- poor quality, lighting, condition. This truly shows that video footage, which we normally regard as a useful tool in a crime, is actually quite useless. Overall, great job!
David did a good job in writing the article. It was interesting to learn how footage is used to help solve crimes.
This article was very exhilirating due to the progress made with video imaging connected with crime scene analysis. The importance of crime scenes being caught on tape is huge as it can contribute to a quick identification of the criminal. Learning about the recreation of an image for a crime was very interesting as well as the bit about sketch artistts. If there was something about how some of the people involved in video analysis and sketching trained to get a job in this area. Overall this article was very interesting and helped me get a greater grasp on video surveilance.
I enjoyed reading this article, I found it to be quite fascinating. I've always thought that video taping would be seen as a useful technique, but apparently not in the forensic field. I didn't have any previous knowledge of this information, so it was nice reading something I didn't know. David did a fine job at summing up the article! I thought he did really well, and if anything, an example of two on how video taping didn't work out would have been useful, but regardless, good job!
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