Check if image is on the red part of another image

[AlphaMensch]

hi,

I know it is very difficult to understand my question...
I want to know, how I can check if an image is on the red (or black but not blank) part of another image like a shape.
Because I want to add images to the view but only at a special place for example:
I generate 500 points randomly. So a random X and Y. But if the coordinate is out of a shape thy shouldn't be add.

I hope you understand and can help me .

Thanks
AlphaMensch

[baja_yu]

Search for colorAtPixel extension to UIImage. It adds methods to UIImage which you can use to determine the exact color on a given point of an image. With that you can check if a certain point is black, red or anything else, even transparent (alpha = 0)

[AlphaMensch]

Originally Posted by baja_yu

Search for colorAtPixel extension to UIImage. It adds methods to UIImage which you can use to determine the exact color on a given point of an image. With that you can check if a certain point is black, red or anything else, even transparent (alpha = 0)

Does this work with objective c, too? Not only with Cocoa?

[baja_yu]

Objective C is a programming language, Cocoa is a framework. If you meant CocoaTouch, yes it does.