UIImage에서 구멍을 자르는 방법?

Question

마스크를 사용하십시오. 마스크는 투명한 배경을 가진 보통 검은 색 PNG 이미지입니다. 여기 나는 기본 이미지 크기의 보통 흰색 이미지를 만듭니다. 그런 다음 필요한 위치의 흰색 이미지에 마스크를 추가하십시오. 그런 다음 maskImage : WithMask 메서드는 검정 영역 만 제거하기 때문에 마스크를 반전시킵니다. 그래서 마스크처럼 보이는 구멍이있는 기본 이미지가 있습니다. 내가 원하는 위치에. 그리고 그것은 작동합니다. 그러나 다른 위치에 구멍을 하나 더 자르려고하면 - 충돌합니다. 제발 말해줘. 내 잘못이야? (때문에) 유지 실종/릴리스

- (UIImage *)createWhiteImageWithSize:(CGSize)size 
{ 
    UIGraphicsBeginImageContext(size); 
    CGContextSetRGBFillColor(UIGraphicsGetCurrentContext(), 255, 255, 255, 1); 
    CGContextFillRect (UIGraphicsGetCurrentContext(), CGRectMake (0, 0, size.width, size.height)); 
    UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 
    return resultImage; 
} 
- (UIImage *) mergeImage:(UIImage *)backImage with:(UIImage *)frontImage onPosition:(CGPoint)position 
{ 
    CGSize finalSize = backImage.size; 
    CGSize impositionSize = frontImage.size; 
    UIGraphicsBeginImageContext(finalSize); 
    [backImage drawInRect:CGRectMake(0, 0, finalSize.width, finalSize.height)]; 
    [frontImage drawInRect:CGRectMake(position.x, position.y, impositionSize.width, impositionSize.height)]; 
    UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 
    return resultImage; 
} 

- (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage 
{ 
    CGImageRef maskRef = maskImage.CGImage; 

    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef), 
             CGImageGetHeight(maskRef), 
             CGImageGetBitsPerComponent(maskRef), 
             CGImageGetBitsPerPixel(maskRef), 
             CGImageGetBytesPerRow(maskRef), 
             CGImageGetDataProvider(maskRef), NULL, false); 
    CGImageRef masked = CGImageCreateWithMask([image CGImage], mask); 
    return [UIImage imageWithCGImage:masked]; 
} 
- (UIImage *)invertImage:(UIImage *)originalImage 
{ 
    UIGraphicsBeginImageContext(originalImage.size); 
    CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeCopy); 
    [originalImage drawInRect:CGRectMake(0, 0, originalImage.size.width, originalImage.size.height)]; 
    CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeDifference); 
    CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(),[UIColor whiteColor].CGColor); 
    CGContextFillRect(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, originalImage.size.width, originalImage.size.height)); 
    UIImage *returnImage = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 
    return returnImage; 
} 

Answer 1

는 ARC를 사용하지 않는 경우는, 다음의 문제가있을 수 있습니다 :

- (UIImage *)makeAHoleIn:(UIImage *)baseImage withAMask:(UIImage *)mask onPosition:(CGPoint)position 
{ 
    UIImage *whiteImage = [self createWhiteImageWithSize:baseImage.size]; 
    UIImage *goodmask = [self mergeImage:whiteImage with:mask onPosition:position]; 
    UIImage *finalmask = [self invertImage:goodmask]; 
    UIImage *finalImage = [self maskImage:baseImage withMask:finalmask]; 
    return finalImage; 
} 

및 기타 방법 : 여기

주요 방법이다. 내가 찾을 수있는 것들을 추가하려고 시도했습니다 :

- (UIImage *)createWhiteImageWithSize:(CGSize)size 
{ 
    UIGraphicsBeginImageContext(size); 
    CGContextSetRGBFillColor(UIGraphicsGetCurrentContext(), 255, 255, 255, 1); 
    CGContextFillRect (UIGraphicsGetCurrentContext(), CGRectMake (0, 0, size.width, size.height)); 
    UIImage *resultImage = [UIGraphicsGetImageFromCurrentImageContext() retain]; // <-- 
    UIGraphicsEndImageContext(); 
    return [resultImage autorelease]; // <-- 
} 
- (UIImage *) mergeImage:(UIImage *)backImage with:(UIImage *)frontImage onPosition:(CGPoint)position 
{ 
    CGSize finalSize = backImage.size; 
    CGSize impositionSize = frontImage.size; 
    UIGraphicsBeginImageContext(finalSize); 
    [backImage drawInRect:CGRectMake(0, 0, finalSize.width, finalSize.height)]; 
    [frontImage drawInRect:CGRectMake(position.x, position.y, impositionSize.width, impositionSize.height)]; 
    UIImage *resultImage = [UIGraphicsGetImageFromCurrentImageContext() retain]; // <-- 
    UIGraphicsEndImageContext(); 
    return [resultImage autorelease]; // <-- 
} 

- (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage 
{ 
    CGImageRef maskRef = maskImage.CGImage; 

    CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef), 
             CGImageGetHeight(maskRef), 
             CGImageGetBitsPerComponent(maskRef), 
             CGImageGetBitsPerPixel(maskRef), 
             CGImageGetBytesPerRow(maskRef), 
             CGImageGetDataProvider(maskRef), NULL, false); 
    CGImageRef masked = CGImageCreateWithMask([image CGImage], mask); 
    UIImage *image = [UIImage imageWithCGImage:masked]; 
    CGImageRelease(mask); // <-- 
    CGImageRelease(masked); // <-- 
    return image; 
} 
- (UIImage *)invertImage:(UIImage *)originalImage 
{ 
    UIGraphicsBeginImageContext(originalImage.size); 
    CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeCopy); 
    [originalImage drawInRect:CGRectMake(0, 0, originalImage.size.width, originalImage.size.height)]; 
    CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeDifference); 
    CGContextSetFillColorWithColor(UIGraphicsGetCurrentContext(),[UIColor whiteColor].CGColor); 
    CGContextFillRect(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, originalImage.size.width, originalImage.size.height)); 
    UIImage *returnImage = [UIGraphicsGetImageFromCurrentImageContext(); // <-- 
    UIGraphicsEndImageContext(); 
    return [returnImage autorelease]; // <-- 
}