我想用我已经拥有的颜色信息创建一个CGImage
以下是将CGImage转换为CML的代码,CML_color是一种矩阵结构
- (void)CGImageReftoCML:(CGImageRef)image destination:(CML_color &)dest{
CML_RGBA p;
NSUInteger width=CGImageGetWidth(image);
NSUInteger height=CGImageGetHeight(image);
CGColorSpaceRef colorSpace=CGColorSpaceCreateDeviceRGB();
unsigned char *rawData=(unsigned char*)malloc(height*width*4);
NSUInteger bytesPerPixel=4;
NSUInteger bytesPerRow=bytesPerPixel*width;
NSUInteger bitsPerComponent=8;
CGContextRef context=CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGColorSpaceRelease(colorSpace);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), image);
CGContextRelease(context);
int index=0;
for (int i=0; i<height; i++) {
for (int j=0; j<width; j++) {
p.red=rawData[index++];
p.green=rawData[index++];
p.blue=rawData[index++];
p.alpha=rawData[index++];
dest(i,j)=p;
}
}
delete[] rawData;
}
现在我想要反向函数,它将CML转换为CGImage。我知道创建图像的所有颜色和alpha信息,它存储在矩阵CML中,但我该怎么做呢?
答案 0 :(得分:3)
以下是代码:
- (CGImageRef)CMLtoCGImage:(CML_color &)source{
int imageWidth=source.Width();
int imageHeight=source.Height();
char* rgba=(char*)malloc(imageWidth*imageHeight*4);
for (int i=0; i<imageHeight; i++) {
for (int j=0; j<imageWidth; j++) {
rgba[4*(i*imageWidth+j)]=source(i,j).red;
rgba[4*(i*imageWidth+j)+1]=source(i,j).green;
rgba[4*(i*imageWidth+j)+2]=source(i,j).blue;
rgba[4*(i*imageWidth+j)+3]=source(i,j).alpha;
}
}
CGColorSpaceRef colorSpace=CGColorSpaceCreateDeviceRGB();
CGContextRef bitmapContext=CGBitmapContextCreate(rgba, imageWidth, imageHeight, 8, 4*imageWidth, colorSpace, kCGImageAlphaNoneSkipLast);
CFRelease(colorSpace);
CGImageRef cgImage=CGBitmapContextCreateImage(bitmapContext);
free(rgba);
return cgImage;
}