178 HW1 - the reflections of light in the eyes By doing so it is possible to check for consistency in light sources and orientation which is used

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#1 There are several ways an image analyst can go about detecting manipulations in photographs. All photo-manipulation software have unique quantization tables embedded within each picture file it creates. Therefore, it is possible to tell which program, and even which camera, was used to create the image. Another technique is to examine the parameters a picture uses to create its thumbnail. The Thumbnail is created by filtering the full size image, selectively removing pixels, then by filtering it again. By examining the algorithms that were used to create this thumbnail, it is possible to remake the original image. Another way to detect any altercations, particularly in photos of people, is by examining
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Unformatted text preview: the reflections of light in the eyes. By doing so, it is possible to check for consistency in light sources and orientation, which is used to validate the photo’s authenticity #2 % Pseudocode % For each pixel p in the image, assign distance D to closest object % pixel q % Given Pixels: p,q % Given Pixel Coordinates: (p1,p2), (q1,q2) % Calculate cityblock distance: D(p,q)=(abs(p1-q1)+abs(p2-q2) % D = Distance Transform %Implement bw = zeros(200,200); bw(50,50) = 1; bw(50,150) = 1; bw(150,100) = 1; D = bwdist(bw, 'cityblock' ); #3...
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This note was uploaded on 11/01/2011 for the course ANTHRO 5 taught by Professor Gaulin during the Spring '11 term at San Diego.

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