如何修剪出特定位置的圖像並設定爲從特定位置的另一視圖

Question

裁剪圖像，並設置爲另一個視圖

最終圖像視圖

self.finalImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 20, 320, 320)]; 
if(rectangle_button_preesed_view) 
{ 
    self.finalImageView.image =[self croppIngimageByImageName:self.imageView.image toRect:CGRectMake(30, 120, 260, 340)]; 
} 
else 
{ 
    self.finalImageView.image =[self croppIngimageByImageName:self.imageView.image toRect:CGRectMake(30, 80, 260, 260)]; 
} 

裁剪圖像

- (UIImage *)croppIngimageByImageName:(UIImage *)imageToCrop toRect:(CGRect)rect 
{ 
    CGImageRef imageRef = CGImageCreateWithImageInRect([imageToCrop CGImage], rect); 
    UIImage *cropped = [UIImage imageWithCGImage:imageRef]; 
    CGImageRelease(imageRef); 
    NSLog(@" cropped size %f %f ",cropped.size.width,cropped.size.height); 
    return cropped;  
} 

Answer 1

@implementation UIImage (Crop) 

- (UIImage *)crop:(CGRect)cropRect { 

    CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], cropRect); 
    UIImage *cropedImage = [UIImage imageWithCGImage:imageRef]; 
    CGImageRelease(imageRef); 

    return cropedImage; 

} 

Answer 2

CGImageRef imageRef = CGImageCreateWithImageInRect([largeImage CGImage], cropRect); 
// or use the UIImage wherever you like 
[UIImageView setImage:[UIImage imageWithCGImage:imageRef]]; 
CGImageRelease(imageRef); 

OR

@implementation UIImage (Crop) 

- (UIImage *)crop:(CGRect)rect { 

    rect = CGRectMake(rect.origin.x*self.scale, 
         rect.origin.y*self.scale, 
         rect.size.width*self.scale, 
         rect.size.height*self.scale);  

    CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], rect); 
    UIImage *result = [UIImage imageWithCGImage:imageRef 
              scale:self.scale 
            orientation:self.imageOrientation]; 
    CGImageRelease(imageRef); 
    return result; 
} 

@end 

Answer 3

除了CoreGraphics的解決方案，我也建議使用CoreImage支持的圖像處理過濾器。您應該查看this documentation page中的CICrop篩選器。

注意：此過濾器支持iOS 5或更高版本。

我目前沒有確切的解決方案，但可以繼續使用a similar thread。

希望它有幫助！