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Fix the CGImageCreateScaled to support 16/32 bits CGImage (RGB161616), and always preserve pixel format info

This commit is contained in:
DreamPiggy 2023-07-28 21:33:36 +08:00
parent 8dbf8ed97a
commit d25ee5b094
2 changed files with 77 additions and 19 deletions
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1
SDWebImage/Core/SDImageCoderHelper.h
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@ -131,6 +131,7 @@ typedef struct SDImagePixelFormat {
Create a scaled CGImage by the provided CGImage and size. This follows The Create Rule and you are response to call release after usage.
It will detect whether the image size matching the scale size, if not, stretch the image to the target size.
@note If you need to keep aspect ratio, you can calculate the scale size by using `scaledSizeWithImageSize` first.
@note This scale does not change pixel format (which means RGB888 in, RGB888 out), supports 8/16/32 bit depth. But the method in UIImage+Transform does not gurantee this.
@param cgImage The CGImage
@param size The scale size in pixel.

95
SDWebImage/Core/SDImageCoderHelper.m
View File

@ -434,45 +434,102 @@ static const CGFloat kDestSeemOverlap = 2.0f; // the numbers of pixels to over
if (!cgImage) {
return NULL;
}
if (size.width == 0 || size.height == 0) {
return NULL;
}
size_t width = CGImageGetWidth(cgImage);
size_t height = CGImageGetHeight(cgImage);
if (width == size.width && height == size.height) {
// Already same size
CGImageRetain(cgImage);
return cgImage;
}
size_t bitsPerComponent = CGImageGetBitsPerComponent(cgImage);
size_t bitsPerPixel = CGImageGetBitsPerPixel(cgImage);
CGColorSpaceRef colorSpace = CGImageGetColorSpace(cgImage);
CGColorRenderingIntent renderingIntent = CGImageGetRenderingIntent(cgImage);
CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(cgImage);
CGBitmapInfo bitmapInfo = (uint32_t)alphaInfo;
uint32_t components = 4; // Input convert to alpha
if (alphaInfo == kCGImageAlphaNone) {
// Convert RGB8/16/F -> ARGB8/16/F
bitmapInfo = (uint32_t)kCGImageAlphaFirst;
} else if (alphaInfo == kCGImageAlphaOnly) {
// Alpha only, simple to 1 channel
components = 1;
}
if (bitsPerComponent == 32) {
bitmapInfo |= kCGBitmapByteOrder32Host;
} else if (bitsPerComponent == 16) {
bitmapInfo |= kCGBitmapByteOrder16Host;
} else if (bitsPerComponent == 8) {
bitmapInfo |= kCGBitmapByteOrderDefault;
} else {
// Unsupported
return NULL;
}
__block vImage_Buffer input_buffer = {}, output_buffer = {};
@onExit {
if (input_buffer.data) free(input_buffer.data);
if (output_buffer.data) free(output_buffer.data);
};
BOOL hasAlpha = [self CGImageContainsAlpha:cgImage];
// kCGImageAlphaNone is not supported in CGBitmapContextCreate.
// Check #3330 for more detail about why this bitmap is choosen.
// From v5.17.0, use runtime detection of bitmap info instead of hardcode.
CGBitmapInfo bitmapInfo = [SDImageCoderHelper preferredPixelFormat:hasAlpha].bitmapInfo;
// Always provide alpha channel
vImage_CGImageFormat format = (vImage_CGImageFormat) {
.bitsPerComponent = 8,
.bitsPerPixel = 32,
.colorSpace = NULL,
.bitsPerComponent = (uint32_t)bitsPerComponent,
.bitsPerPixel = (uint32_t)bitsPerComponent * components,
.colorSpace = colorSpace,
.bitmapInfo = bitmapInfo,
.version = 0,
.decode = NULL,
.renderingIntent = CGImageGetRenderingIntent(cgImage)
.renderingIntent = renderingIntent
};
vImage_Error a_ret = vImageBuffer_InitWithCGImage(&input_buffer, &format, NULL, cgImage, kvImageNoFlags);
if (a_ret != kvImageNoError) return NULL;
output_buffer.width = MAX(size.width, 0);
output_buffer.height = MAX(size.height, 0);
output_buffer.rowBytes = SDByteAlign(output_buffer.width * 4, 64);
output_buffer.data = malloc(output_buffer.rowBytes * output_buffer.height);
// input
vImage_Error ret = vImageBuffer_InitWithCGImage(&input_buffer, &format, NULL, cgImage, kvImageNoFlags);
if (ret != kvImageNoError) return NULL;
// output
vImageBuffer_Init(&output_buffer, size.height, size.width, (uint32_t)bitsPerComponent * components, kvImageNoFlags);
if (!output_buffer.data) return NULL;
vImage_Error ret = vImageScale_ARGB8888(&input_buffer, &output_buffer, NULL, kvImageHighQualityResampling);
if (components == 4) {
if (bitsPerComponent == 32) {
ret = vImageScale_ARGBFFFF(&input_buffer, &output_buffer, NULL, kvImageHighQualityResampling);
} else if (bitsPerComponent == 16) {
ret = vImageScale_ARGB16U(&input_buffer, &output_buffer, NULL, kvImageHighQualityResampling);
} else if (bitsPerComponent == 8) {
ret = vImageScale_ARGB8888(&input_buffer, &output_buffer, NULL, kvImageHighQualityResampling);
}
} else {
if (bitsPerComponent == 32) {
ret = vImageScale_PlanarF(&input_buffer, &output_buffer, NULL, kvImageHighQualityResampling);
} else if (bitsPerComponent == 16) {
ret = vImageScale_Planar16U(&input_buffer, &output_buffer, NULL, kvImageHighQualityResampling);
} else if (bitsPerComponent == 8) {
ret = vImageScale_Planar8(&input_buffer, &output_buffer, NULL, kvImageHighQualityResampling);
}
}
if (ret != kvImageNoError) return NULL;
CGImageRef outputImage = vImageCreateCGImageFromBuffer(&output_buffer, &format, NULL, NULL, kvImageNoFlags, &ret);
// Convert back to non-alpha for RGB input to preserve pixel format
if (alphaInfo == kCGImageAlphaNone) {
// in-place, no extra allocation
if (bitsPerComponent == 32) {
ret = vImageConvert_ARGBFFFFtoRGBFFF(&output_buffer, &output_buffer, kvImageNoFlags);
} else if (bitsPerComponent == 16) {
ret = vImageConvert_ARGB16UtoRGB16U(&output_buffer, &output_buffer, kvImageNoFlags);
} else if (bitsPerComponent == 8) {
ret = vImageConvert_ARGB8888toRGB888(&output_buffer, &output_buffer, kvImageNoFlags);
}
}
vImage_CGImageFormat output_format = (vImage_CGImageFormat) {
.bitsPerComponent = (uint32_t)bitsPerComponent,
.bitsPerPixel = (uint32_t)bitsPerPixel,
.colorSpace = colorSpace,
.bitmapInfo = CGImageGetBitmapInfo(cgImage),
.version = 0,
.decode = NULL,
.renderingIntent = renderingIntent
};
CGImageRef outputImage = vImageCreateCGImageFromBuffer(&output_buffer, &output_format, NULL, NULL, kvImageNoFlags, &ret);
if (ret != kvImageNoError) {
CGImageRelease(outputImage);
return NULL;