Merge pull request opencv#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

cmake/templates/opencv_abi.xml.in

@@ -32,6 +32,7 @@
     opencv2/flann/hdf5.h
     opencv2/imgcodecs/imgcodecs_c.h
     opencv2/imgcodecs/ios.h
+    opencv2/imgcodecs/macosx.h
     opencv2/videoio/videoio_c.h
     opencv2/videoio/cap_ios.h
     opencv2/xobjdetect/private.hpp

modules/imgcodecs/CMakeLists.txt

@@ -113,10 +113,18 @@ file(GLOB imgcodecs_ext_hdrs
      "${CMAKE_CURRENT_LIST_DIR}/include/opencv2/${name}/legacy/*.h"
      )
 
+if(APPLE)
+  list(APPEND imgcodecs_srcs ${CMAKE_CURRENT_LIST_DIR}/src/apple_conversions.h)
+  list(APPEND imgcodecs_srcs ${CMAKE_CURRENT_LIST_DIR}/src/apple_conversions.mm)
+endif()
 if(IOS)
   list(APPEND imgcodecs_srcs ${CMAKE_CURRENT_LIST_DIR}/src/ios_conversions.mm)
   list(APPEND IMGCODECS_LIBRARIES "-framework UIKit" "-framework AssetsLibrary")
 endif()
+if(APPLE AND (NOT IOS))
+  list(APPEND imgcodecs_srcs ${CMAKE_CURRENT_LIST_DIR}/src/macosx_conversions.mm)
+  list(APPEND IMGCODECS_LIBRARIES "-framework AppKit")
+endif()
 if(APPLE_FRAMEWORK)
   list(APPEND IMGCODECS_LIBRARIES "-framework Accelerate" "-framework CoreGraphics" "-framework QuartzCore")
 endif()

modules/imgcodecs/include/opencv2/imgcodecs.hpp

@@ -50,6 +50,7 @@
   @{
     @defgroup imgcodecs_c C API
     @defgroup imgcodecs_ios iOS glue
+    @defgroup imgcodecs_macosx MacOS(OSX) glue
   @}
 */
 

modules/imgcodecs/include/opencv2/imgcodecs/macosx.h

@@ -0,0 +1,20 @@
+// 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.
+
+#if !defined(__APPLE__) || !defined(__MACH__)
+#error This header should be used in macOS ObjC/Swift projects.
+#endif
+
+#import <AppKit/AppKit.h>
+#include "opencv2/core.hpp"
+
+//! @addtogroup imgcodecs_macosx
+//! @{
+
+CV_EXPORTS CGImageRef MatToCGImage(const cv::Mat& image);
+CV_EXPORTS void CGImageToMat(const CGImageRef image, cv::Mat& m, bool alphaExist = false);
+CV_EXPORTS NSImage* MatToNSImage(const cv::Mat& image);
+CV_EXPORTS void NSImageToMat(const NSImage* image, cv::Mat& m, bool alphaExist = false);
+
+//! @}

modules/imgcodecs/misc/objc/macosx/Mat+Converters.h

@@ -0,0 +1,32 @@
+//
+//  Mat+Converters.h
+//
+//  Created by Masaya Tsuruta on 2020/10/08.
+//
+
+#pragma once
+
+#ifdef __cplusplus
+#import "opencv.hpp"
+#else
+#define CV_EXPORTS
+#endif
+
+#import <Foundation/Foundation.h>
+#import <AppKit/AppKit.h>
+#import "Mat.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+CV_EXPORTS @interface Mat (Converters)
+
+-(CGImageRef)toCGImage;
+-(instancetype)initWithCGImage:(CGImageRef)image;
+-(instancetype)initWithCGImage:(CGImageRef)image alphaExist:(BOOL)alphaExist;
+-(NSImage*)toNSImage;
+-(instancetype)initWithNSImage:(NSImage*)image;
+-(instancetype)initWithNSImage:(NSImage*)image alphaExist:(BOOL)alphaExist;
+
+@end
+
+NS_ASSUME_NONNULL_END

modules/imgcodecs/misc/objc/macosx/Mat+Converters.mm

@@ -0,0 +1,44 @@
+//
+//  Mat+Converters.mm
+//
+//  Created by Masaya Tsuruta on 2020/10/08.
+//
+
+#import "Mat+Converters.h"
+#import <opencv2/imgcodecs/macosx.h>
+
+@implementation Mat (Converters)
+
+-(CGImageRef)toCGImage {
+    return MatToCGImage(self.nativeRef);
+}
+
+-(instancetype)initWithCGImage:(CGImageRef)image {
+    return [self initWithCGImage:image alphaExist:NO];
+}
+
+-(instancetype)initWithCGImage:(CGImageRef)image alphaExist:(BOOL)alphaExist {
+    self = [self init];
+    if (self) {
+        CGImageToMat(image, self.nativeRef, (bool)alphaExist);
+    }
+    return self;
+}
+
+-(NSImage*)toNSImage {
+    return MatToNSImage(self.nativeRef);
+}
+
+-(instancetype)initWithNSImage:(NSImage*)image {
+    return [self initWithNSImage:image alphaExist:NO];
+}
+
+-(instancetype)initWithNSImage:(NSImage*)image alphaExist:(BOOL)alphaExist {
+    self = [self init];
+    if (self) {
+        NSImageToMat(image, self.nativeRef, (bool)alphaExist);
+    }
+    return self;
+}
+
+@end

modules/imgcodecs/src/apple_conversions.h

@@ -0,0 +1,11 @@
+// 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.
+
+#import <Accelerate/Accelerate.h>
+#import <AVFoundation/AVFoundation.h>
+#import <ImageIO/ImageIO.h>
+#include "opencv2/core.hpp"
+
+CV_EXPORTS CGImageRef MatToCGImage(const cv::Mat& image);
+CV_EXPORTS void CGImageToMat(const CGImageRef image, cv::Mat& m, bool alphaExist);

modules/imgcodecs/src/apple_conversions.mm

@@ -0,0 +1,94 @@
+// 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);
+}

modules/imgcodecs/src/ios_conversions.mm

@@ -41,105 +41,23 @@
 //M*/
 
 #import <UIKit/UIKit.h>
-#import <Accelerate/Accelerate.h>
-#import <AVFoundation/AVFoundation.h>
-#import <ImageIO/ImageIO.h>
-#include "opencv2/core.hpp"
-#include "precomp.hpp"
+#include "apple_conversions.h"
 
 CV_EXPORTS UIImage* MatToUIImage(const cv::Mat& image);
 CV_EXPORTS void UIImageToMat(const UIImage* image, cv::Mat& m, bool alphaExist);
 
 UIImage* MatToUIImage(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
-                                        );
-
+    CGImageRef imageRef = MatToCGImage(image);
 
     // Getting UIImage from CGImage
-    UIImage *finalImage = [UIImage imageWithCGImage:imageRef];
+    UIImage *uiImage = [UIImage imageWithCGImage:imageRef];
     CGImageRelease(imageRef);
-    CGDataProviderRelease(provider);
-    CGColorSpaceRelease(colorSpace);
 
-    return finalImage;
+    return uiImage;
 }
 
-void UIImageToMat(const UIImage* image,
-                         cv::Mat& m, bool alphaExist) {
-    CGColorSpaceRef colorSpace = CGImageGetColorSpace(image.CGImage);
-    CGFloat cols = CGImageGetWidth(image.CGImage), rows = CGImageGetHeight(image.CGImage);
-    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.CGImage);
-    CGContextRelease(contextRef);
+void UIImageToMat(const UIImage* image, cv::Mat& m, bool alphaExist) {
+    CGImageRef imageRef = image.CGImage;
+    CGImageToMat(imageRef, m, alphaExist);
 }

modules/imgcodecs/src/macosx_conversions.mm

@@ -0,0 +1,25 @@
+// 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.
+
+#import <AppKit/AppKit.h>
+#include "apple_conversions.h"
+
+CV_EXPORTS NSImage* MatToNSImage(const cv::Mat& image);
+CV_EXPORTS void NSImageToMat(const NSImage* image, cv::Mat& m, bool alphaExist);
+
+NSImage* MatToNSImage(const cv::Mat& image) {
+    // Creating CGImage from cv::Mat
+    CGImageRef imageRef = MatToCGImage(image);
+
+    // Getting NSImage from CGImage
+    NSImage *nsImage = [[NSImage alloc] initWithCGImage:imageRef size:CGSizeMake(CGImageGetWidth(imageRef), CGImageGetHeight(imageRef))];
+    CGImageRelease(imageRef);
+
+    return nsImage;
+}
+
+void NSImageToMat(const NSImage* image, cv::Mat& m, bool alphaExist) {
+    CGImageRef imageRef = [image CGImageForProposedRect:NULL context:NULL hints:NULL];
+    CGImageToMat(imageRef, m, alphaExist);
+}

modules/objc/generator/gen_objc.py

@@ -1584,6 +1584,11 @@ def sanitize_documentation_string(doc, type):
             if os.path.exists(ios_files_dir):
                 copied_files += copy_objc_files(ios_files_dir, objc_base_path, module, True)
 
+        if args.target == 'osx':
+            osx_files_dir = os.path.join(misc_location, 'macosx')
+            if os.path.exists(osx_files_dir):
+                copied_files += copy_objc_files(osx_files_dir, objc_base_path, module, True)
+
         objc_test_files_dir = os.path.join(misc_location, 'test')
         if os.path.exists(objc_test_files_dir):
             copy_objc_files(objc_test_files_dir, objc_test_base_path, 'test', False)