IOS - CoreImage composite one image to another image at specific location

Question

Sorry if I am posting a duplicated question.

I am newbie in IOS programming with CoreImage. I am going to composite an image over another image. The problem is the Composite filters from Core image don't support a composition at specific location. It is compositing the two images at the location (0,0) only.

For example, I need to composite an image at the location (100,100) of another image, not at the left-top corner.

Any suggestion for this issue must be appreciated.

Answer 1

What you want to do, I believe, is move the image you want offset to the correct location before applying the composite filter. You can create a CGAffineTransform to do this like so:

CGAffineTransform transform = CGAffineTransformMakeTranslation(100, 100);
CIImage *adjustedImage = [inputImage imageByApplyingTransform:transform]; 

Alternatively there is a CIAffineTransform filter which does the same job. Once you've got your transformed image, you can comp it with the other image normally and it should appear offset in the output.