Merge pull request #4115 from themightyoarfish:MatToUIImage_transparency

bf843477 · Vadim Pisarevsky · e055128d · 125782c0 · bf843477
Commit bf843477 authored Jun 17, 2015 by Vadim Pisarevsky
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Showing with 5 additions and 2 deletions

ios_conversions.mm modules/imgcodecs/src/ios_conversions.mm +5 -2

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--- a/modules/imgcodecs/src/ios_conversions.mm
+++ b/modules/imgcodecs/src/ios_conversions.mm
@@ -66,6 +66,10 @@ UIImage* MatToUIImage(const cv::Mat& image) {
    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,
@@ -73,8 +77,7 @@ UIImage* MatToUIImage(const cv::Mat& image) {
                                        8 * image.elemSize(),
                                        image.step.p[0],
                                        colorSpace,
-                                        kCGImageAlphaNone|
-                                        kCGBitmapByteOrderDefault,
+                                        bitmapInfo,
                                        provider,
                                        NULL,
                                        false,