From 0e69cddda20c495d4908c459c2f97c2861cd8ce8 Mon Sep 17 00:00:00 2001
From: okamotoR <takehiroshitakehiii@icloud.com>
Date: Tue, 23 Jun 2020 21:36:47 +0900
Subject: [PATCH] add if block for indexed color images

---
 modules/imgcodecs/src/ios_conversions.mm | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/modules/imgcodecs/src/ios_conversions.mm b/modules/imgcodecs/src/ios_conversions.mm
index e3363c28ae..53fb788d65 100644
--- a/modules/imgcodecs/src/ios_conversions.mm
+++ b/modules/imgcodecs/src/ios_conversions.mm
@@ -112,6 +112,21 @@ void UIImageToMat(const UIImage* image,
                                            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