CGImage载入的图片，查看bit地图详细信息的一段好用代码

CGImage载入的图片，查看bitmap详细信息的一段好用代码

在IOS中，载入一张图片到CGImage后，如果想查看图片的信息，这里有一段比较好的代码可以帮助你，其他的信息要显示可以参考苹果的API自己设置！

-(void)imageDump:(NSString*)file
{
    UIImage* image = [UIImage imageNamed:file];
    CGImageRef cgimage = image.CGImage;

    size_t width  = CGImageGetWidth(cgimage);
    size_t height = CGImageGetHeight(cgimage);

    size_t bpr = CGImageGetBytesPerRow(cgimage);
    size_t bpp = CGImageGetBitsPerPixel(cgimage);
    size_t bpc = CGImageGetBitsPerComponent(cgimage);
    size_t bytes_per_pixel = bpp / bpc;

    CGBitmapInfo info = CGImageGetBitmapInfo(cgimage);

    NSLog(
        @"\n"
        "===== %@ =====\n"
        "CGImageGetHeight: %d\n"
        "CGImageGetWidth:  %d\n"
        "CGImageGetColorSpace: %@\n"
        "CGImageGetBitsPerPixel:     %d\n"
        "CGImageGetBitsPerComponent: %d\n"
        "CGImageGetBytesPerRow:      %d\n"
        "CGImageGetBitmapInfo: 0x%.8X\n"
        "  kCGBitmapAlphaInfoMask     = %s\n"
        "  kCGBitmapFloatComponents   = %s\n"
        "  kCGBitmapByteOrderMask     = %s\n"
        "  kCGBitmapByteOrderDefault  = %s\n"
        "  kCGBitmapByteOrder16Little = %s\n"
        "  kCGBitmapByteOrder32Little = %s\n"
        "  kCGBitmapByteOrder16Big    = %s\n"
        "  kCGBitmapByteOrder32Big    = %s\n",
        file,
        (int)width,
        (int)height,
        CGImageGetColorSpace(cgimage),
        (int)bpp,
        (int)bpc,
        (int)bpr,
        (unsigned)info,
        (info & kCGBitmapAlphaInfoMask)     ? "YES" : "NO",
        (info & kCGBitmapFloatComponents)   ? "YES" : "NO",
        (info & kCGBitmapByteOrderMask)     ? "YES" : "NO",
        (info & kCGBitmapByteOrderDefault)  ? "YES" : "NO",
        (info & kCGBitmapByteOrder16Little) ? "YES" : "NO",
        (info & kCGBitmapByteOrder32Little) ? "YES" : "NO",
        (info & kCGBitmapByteOrder16Big)    ? "YES" : "NO",
        (info & kCGBitmapByteOrder32Big)    ? "YES" : "NO"
    );

    CGDataProviderRef provider = CGImageGetDataProvider(cgimage);
    NSData* data = (id)CGDataProviderCopyData(provider);
    [data autorelease];
    const uint8_t* bytes = [data bytes];

    printf("Pixel Data:\n");
    for(size_t row = 0; row < height; row++)
    {
        for(size_t col = 0; col < width; col++)
        {
            const uint8_t* pixel =
                &bytes[row * bpr + col * bytes_per_pixel];

            printf("(");
            for(size_t x = 0; x < bytes_per_pixel; x++)
            {
                printf("%.2X", pixel[x]);
                if( x < bytes_per_pixel - 1 )
                    printf(",");
            }

            printf(")");
            if( col < width - 1 )
                printf(", ");
        }

        printf("\n");
    }
}

效果如下：：：

===== a.png =====
CGImageGetHeight: 5
CGImageGetWidth:  3
CGImageGetColorSpace: <CGColorSpace 0x4d08ff0> (kCGColorSpaceDeviceRGB)
CGImageGetBitsPerPixel:     32
CGImageGetBitsPerComponent: 8
CGImageGetBytesPerRow:      20
CGImageGetBitmapInfo: 0x00000003
  kCGBitmapAlphaInfoMask     = YES
  kCGBitmapFloatComponents   = NO
  kCGBitmapByteOrderMask     = NO
  kCGBitmapByteOrderDefault  = NO
  kCGBitmapByteOrder16Little = NO
  kCGBitmapByteOrder32Little = NO
  kCGBitmapByteOrder16Big    = NO
  kCGBitmapByteOrder32Big    = NO
Pixel Data:
(00,00,00,FF), (FF,FF,FF,FF), (FF,00,00,FF), (00,FF,00,FF), (00,00,FF,FF)
(00,00,00,FF), (FF,FF,FF,FF), (FF,00,00,FF), (00,FF,00,FF), (00,00,FF,FF)
(FF,FF,FF,00), (FF,FF,FF,00), (FF,FF,FF,00), (FF,FF,FF,00), (FF,FF,FF,00)


===== b.png =====
CGImageGetHeight: 5
CGImageGetWidth:  3
CGImageGetColorSpace: <CGColorSpace 0x4d08ff0> (kCGColorSpaceDeviceRGB)
CGImageGetBitsPerPixel:     24
CGImageGetBitsPerComponent: 8
CGImageGetBytesPerRow:      15
CGImageGetBitmapInfo: 0x00000000
  kCGBitmapAlphaInfoMask     = NO
  kCGBitmapFloatComponents   = NO
  kCGBitmapByteOrderMask     = NO
  kCGBitmapByteOrderDefault  = NO
  kCGBitmapByteOrder16Little = NO
  kCGBitmapByteOrder32Little = NO
  kCGBitmapByteOrder16Big    = NO
  kCGBitmapByteOrder32Big    = NO
Pixel Data:
(00,00,00), (FF,FF,FF), (FF,00,00), (00,FF,00), (00,00,FF)
(00,00,00), (FF,FF,FF), (FF,00,00), (00,FF,00), (00,00,FF)
(00,00,00), (FF,FF,FF), (FF,00,00), (00,FF,00), (00,00,FF)