Come tagliare una grande sprite png in UIImages più piccoli?

Question

Ad esempio, il file png è 1200 (h) x 50 (w) pixel, come posso tagliare il png e carichi in 6 UIImage s, ogni 200 (h) x 50 (w). Grazie!

EDIT - grazie alla risposta di Michal, il codice finale:

CGImageRef imageToSplit = [UIImage imageNamed:@"huge.png"].CGImage; 
CGImageRef partOfImageAsCG = CGImageCreateWithImageInRect(imageToSplit, CGRectMake(0, 0, 50, 50)); 

UIImage *partOfImage = [UIImage imageWithCGImage:partOfImageAsCG]; 
// ... 

CGImageRelease(partOfImageAsCG); 

Answer 1

Guardate la funzione CGImageCreateWithImageInRect. Funziona con CGImage, ma è facile convertire tra quello e UIImage.

Ecco un esempio (digitato dalla memoria, potrebbe non compilare):

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

Metodo riutilizzabile:

-(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? bcuz it has name create in its method so the ownership comes to us so we have to release it. 

    return ExtractedImage; 


} 

FYI:

Benche 'è stato risposto Chiaramente ho pensato di dargli un semplice snoppet di codice "Copia-Incolla" riutilizzabile sarebbe un grande aiuto t o programmatori e attribuisco la risposta a michal