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我从相机胶卷加载图像,但此图像是颠倒。所以我写了方法来旋转它。我旋转图像倒过来,但如何水平翻转它
CGImageRef imageRef = [image CGImage];
float width = CGImageGetWidth(imageRef);
float height = CGImageGetHeight(imageRef);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
Byte *rawData = malloc(height * width * 4);
Byte bytesPerPixel = 4;
int bytesPerRow = bytesPerPixel * width;
Byte bitsPerComponent = 8;
CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
int byteIndex = 0;
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
Byte *rawData2 = malloc(height * width * 4);
for (int i = 0 ; i < width * height ; i++) {
int index = (width * height) * 4;
rawData2[byteIndex + 0] = rawData[index - byteIndex + 0];
rawData2[byteIndex + 1] = rawData[index - byteIndex + 1];
rawData2[byteIndex + 2] = rawData[index - byteIndex + 2];
rawData2[byteIndex + 3] = rawData[index - byteIndex + 3];
byteIndex += 4;
}
CGContextRef ctx = CGBitmapContextCreate(rawData2, CGImageGetWidth(imageRef), CGImageGetHeight(imageRef), 8, CGImageGetBytesPerRow(imageRef), CGImageGetColorSpace(imageRef),kCGImageAlphaPremultipliedLast);
imageRef = CGBitmapContextCreateImage (ctx);
image = [UIImage imageWithCGImage:imageRef];
CGContextRelease(context);
return image;
没关系,但现在我必须水平翻转它,我不知道我该怎么做。我尝试第二天做这个。
谢谢大家帮忙
我必须转换UIImage并在CGContextRef上绘制它,所以'.transform'不可用。我尝试将UIImage添加到UIImageView,旋转它并生成'image = imageView.image',但它不起作用。 – 2012-07-29 10:33:01
请查看我的编辑,了解如何将视图内容“转换”为图像。 – sergio 2012-07-29 10:35:26
它正在工作,但我设置了'imageview.frame = CGRectMake(111,122,768,1024)'并且它在'0,0,768,1024'处渲染上下文。任何建议? – 2012-07-29 11:26:37