How to cut a large sprite png into smaller UIImages?

Question

For example, the png file is 1200 (h) x 50 (w) pixels, how can I cut the png and loads in 6 UIImages, each 200 (h) x 50 (w). Thanks!

EDIT - thanks

Answer 1

Look at CGImageCreateWithImageInRect function. It works with CGImage, but it's easy to convert between that one and UIImage.

Here's an example (typed from memory, might not compile):

CGImageRef imageToSplit = [UIImage imageNamed:@"huge.png"].CGImage;
CGImageRef partOfImageAsCG = CGImageCreateWithImageInRect(imageToSplit, CGRectMake(0, 0, 200, 50));
CGRelease(imageToSplit);
UIImage *partOfImage = [UIImage imageWithCGImage:partOfImageAsCG];
CGImageRelease(partOfImageAsCG);

Answer 2

A reusable method:

-(UIImage*)ExtractImageOn:(CGPoint)pointExtractedImg ofSize:(CGSize)sizeExtractedImg FromSpriteSheet:(UIImage*)imgSpriteSheet
{
    UIImage *ExtractedImage;

    CGRect rectExtractedImage;

    rectExtractedImage=CGRectMake(pointExtractedImg.x,pointExtractedImg.y,sizeExtractedImg.width,sizeExtractedImg.height);

    CGImageRef imgRefSpriteSheet=imgSpriteSheet.CGImage;

    CGImageRef imgRefExtracted=CGImageCreateWithImageInRect(imgRefSpriteSheet,rectExtractedImage);

    ExtractedImage=[UIImage imageWithCGImage:imgRefExtracted];

    CGImageRelease(imgRefExtracted);

    //CGImageRelease(imgRefSpriteSheet); I have commented it because
    // we should not release the object that we don't own.
    // So why do we release imgRefExtracted alone? because it has 
    // name create in its method so the ownership comes to us so we
    // have to release it.

    return ExtractedImage;

}

FYI:

Even though it has been answered clearly I thought giving it as simple reusable 'Copy-Paste' code snippet would be a lots of help to programmers and I attribute the answer to michal