pixel value in UIImageView's image

I'm trying to find the value of an pixel in the image displayed in a开发者_运维知识库n UIImageView. getting the pixel on the display is (relatively) simple. But when the image displayed is scaled (say the orgig. image is 1200*1600) it's much more complicated because of the scaling ..

Any good advice ?

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If you're trying to get the pixel value from the original image, this question's accepted answer shows a way to get pixel values from an UIImage.

Edit:

Scaling means a loss of information, so there won't be a one-to-one mapping. One pixel on your scaled-down image corresponds to a patch of pixels in your original image, and the best that you can hope for is a lossy interval mapping from [0..scaledX] to [0..originalX] and from [0..scaledY] to [0..originalY]. An explanation on how to do such a mapping can be found in the answer to this question.