iOS图片裁剪

    UIImage *image = [UIImage imageNamed:@"imageDemo"];
    
    CGRect rect =  CGRectMake(0, 0, 100, 100);//要裁减的区域
    CGImageRef cgimg = CGImageCreateWithImageInRect([image CGImage], rect);
    image = [UIImage imageWithCGImage:cgimg];
    CGImageRelease(cgimg);