From: Niki Roo <niki@nikiroo.be>
Date: Thu, 12 Apr 2018 17:20:41 +0000 (+0200)
Subject: image to text: improve DOUBLE_DITHERING
X-Git-Tag: nikiroo-utils-4.4.0~11
X-Git-Url: http://git.nikiroo.be/?p=nikiroo-utils.git;a=commitdiff_plain;h=9db215c6238d776d39dae5b7c8d805cb6f4e9bd1

image to text: improve DOUBLE_DITHERING
---

diff --git a/src/be/nikiroo/utils/ui/ImageTextAwt.java b/src/be/nikiroo/utils/ui/ImageTextAwt.java
index 8fdaa86..4c0c824 100644
--- a/src/be/nikiroo/utils/ui/ImageTextAwt.java
+++ b/src/be/nikiroo/utils/ui/ImageTextAwt.java
@@ -389,7 +389,13 @@ public class ImageTextAwt {
 				avg += getBrightness(lowerright);
 				avg /= 4;
 
-				return getDitheringChar(avg, " ░▒▓█");
+				// Since all the quarters are > 0.5, avg is between 0.5 and 1.0
+				// So, expand the range of the value
+				avg = (avg - 0.5f) * 2;
+
+				// Do not use the " " char, as it would make a
+				// "all quarters > 0.5" pixel go black
+				return getDitheringChar(avg, "░▒▓█");
 			}
 
 			return '█';