From 2d3da1db6dc6d52905f55dca74856dc103739ae1 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 3 Jan 2023 10:27:31 +0530
Subject: [PATCH] Dont scan all pixels of JPEG images when EXIF rotated to
 check for opacity

---
 tools/cmd/icat/native.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/cmd/icat/native.go b/tools/cmd/icat/native.go
index 854aa2924..009d0db9e 100644
--- a/tools/cmd/icat/native.go
+++ b/tools/cmd/icat/native.go
@@ -28,7 +28,13 @@ func resize_frame(imgd *image_data, img image.Image) (image.Image, image.Rectang
 }
 
 func add_frame(imgd *image_data, img image.Image) *image_frame {
-	is_opaque := images.IsOpaque(img)
+	is_opaque := false
+	if imgd.format_uppercase == "JPEG" {
+		// special cased because EXIF orientation could have already changed this image to an NRGBA making IsOpaque() very slow
+		is_opaque = true
+	} else {
+		is_opaque = images.IsOpaque(img)
+	}
 	b := img.Bounds()
 	if imgd.scaled_frac.x != 0 {
 		img, b = resize_frame(imgd, img)