opencv/modules/imgcodecs/src/apple_conversions.mm
mtfrctl 7de189114b
Merge pull request #18547 from mtfrctl:objc-conversions-macosx
Mat conversions for macOS/AppKit

* Extract CoreGraphics conversion logics from ios_conversions.mm to apple_conversions.h, apple_conversions. Add macosx_conversions.mm

* Add macosx.h

* Add Mat+Conversions.h and Mat+Conversions.mm

* Delete duplicated declaration from apple_conversion.mm

* Use short license header

* Add compile guard

* Delete unused imports

* Move precomp.hpp import from header to implementation

* Add macosx.h to skip headers

* Fix compile guard condition

* Use short license header

* Remove commented out unused code
2020-10-14 16:58:06 +00:00

95 lines
3.7 KiB
Plaintext

// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.
#include "apple_conversions.h"
#include "precomp.hpp"
CGImageRef MatToCGImage(const cv::Mat& image) {
NSData *data = [NSData dataWithBytes:image.data
length:image.step.p[0] * image.rows];
CGColorSpaceRef colorSpace;
if (image.elemSize() == 1) {
colorSpace = CGColorSpaceCreateDeviceGray();
} else {
colorSpace = CGColorSpaceCreateDeviceRGB();
}
CGDataProviderRef provider =
CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
// Preserve alpha transparency, if exists
bool alpha = image.channels() == 4;
CGBitmapInfo bitmapInfo = (alpha ? kCGImageAlphaLast : kCGImageAlphaNone) | kCGBitmapByteOrderDefault;
// Creating CGImage from cv::Mat
CGImageRef imageRef = CGImageCreate(image.cols,
image.rows,
8 * image.elemSize1(),
8 * image.elemSize(),
image.step.p[0],
colorSpace,
bitmapInfo,
provider,
NULL,
false,
kCGRenderingIntentDefault
);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);
return imageRef;
}
void CGImageToMat(const CGImageRef image, cv::Mat& m, bool alphaExist) {
CGColorSpaceRef colorSpace = CGImageGetColorSpace(image);
CGFloat cols = CGImageGetWidth(image), rows = CGImageGetHeight(image);
CGContextRef contextRef;
CGBitmapInfo bitmapInfo = kCGImageAlphaPremultipliedLast;
if (CGColorSpaceGetModel(colorSpace) == kCGColorSpaceModelMonochrome)
{
m.create(rows, cols, CV_8UC1); // 8 bits per component, 1 channel
bitmapInfo = kCGImageAlphaNone;
if (!alphaExist)
bitmapInfo = kCGImageAlphaNone;
else
m = cv::Scalar(0);
contextRef = CGBitmapContextCreate(m.data, m.cols, m.rows, 8,
m.step[0], colorSpace,
bitmapInfo);
}
else if (CGColorSpaceGetModel(colorSpace) == kCGColorSpaceModelIndexed)
{
// CGBitmapContextCreate() does not support indexed color spaces.
colorSpace = CGColorSpaceCreateDeviceRGB();
m.create(rows, cols, CV_8UC4); // 8 bits per component, 4 channels
if (!alphaExist)
bitmapInfo = kCGImageAlphaNoneSkipLast |
kCGBitmapByteOrderDefault;
else
m = cv::Scalar(0);
contextRef = CGBitmapContextCreate(m.data, m.cols, m.rows, 8,
m.step[0], colorSpace,
bitmapInfo);
CGColorSpaceRelease(colorSpace);
}
else
{
m.create(rows, cols, CV_8UC4); // 8 bits per component, 4 channels
if (!alphaExist)
bitmapInfo = kCGImageAlphaNoneSkipLast |
kCGBitmapByteOrderDefault;
else
m = cv::Scalar(0);
contextRef = CGBitmapContextCreate(m.data, m.cols, m.rows, 8,
m.step[0], colorSpace,
bitmapInfo);
}
CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows),
image);
CGContextRelease(contextRef);
}