Objective C compare 2 images and get the differences highlighted

Question

I am building an application, where I need to compare 2 images and highlight the difference. For example I am comparing UIImage1 with UIImage2, where both the images are same, except there is an extra small square object in UIImage2. I need to highlight the extra square object with red color in the UIImage2.

I am not sure, how I can achieve this.

score 2 · Answer 1 · edited May 23 '17 at 12:19

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You can subtract two UIImages by blending them with the blendmode "kCGBlendModeDifference".

Here is an example done, you just have to change the blendmode: https://stackoverflow.com/a/3188761

edited May 23 '17 at 12:19

Community

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answered Sep 13 '16 at 14:13

KugelnMMXVI

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This highlights the extra elements, that is great. But can we change the highlight color? – Soumalya Banerjee Sep 14 '16 at 10:20

Objective C compare 2 images and get the differences highlighted

1 Answers1