From db3654ef51b156feab4f59c13f2ee41ca2ab9a85 Mon Sep 17 00:00:00 2001
From: Kumataro <Kumataro@users.noreply.github.com>
Date: Sun, 21 Jul 2024 10:00:29 +0900
Subject: [PATCH] python: prefer cv::Mat over cv::UMat in python binding

---
 modules/python/src2/gen2.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/modules/python/src2/gen2.py b/modules/python/src2/gen2.py
index 3249c57f82..af187e5d3f 100755
--- a/modules/python/src2/gen2.py
+++ b/modules/python/src2/gen2.py
@@ -854,7 +854,22 @@ class FuncInfo(object):
 
         all_code_variants = []
 
+        # See https://github.com/opencv/opencv/issues/25928
+        # Conversion to UMat is expensive more than conversion to Mat.
+        # To reduce this cost, conversion to Mat is prefer than to UMat.
+        variants = []
+        variants_umat = []
         for v in self.variants:
+            hasUMat = False
+            for a in v.args:
+                hasUMat = hasUMat or "UMat" in a.tp
+            if hasUMat :
+                variants_umat.append(v)
+            else:
+                variants.append(v)
+        variants.extend(variants_umat)
+
+        for v in variants:
             code_decl = ""
             code_ret = ""
             code_cvt_list = []