From 3a87134f3ed02f31066bbc78f1396649ea86880d Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Sat, 19 Mar 2016 16:50:49 +1100
Subject: [PATCH] Fix transparency allocation

Former-commit-id: 85c4d5c0ccd92dce6265040068aeffe851604045
Former-commit-id: 5b59aa6bb210dcc113cee26d2986c172170a9d8e
Former-commit-id: a048ee2bfc5bf0bdbdcbdd709c485ccb6c50d90d
---
 src/ImageProcessorCore/Formats/Gif/GifEncoder.cs      | 5 +++--
 src/ImageProcessorCore/Quantizers/Octree/Quantizer.cs | 2 +-
 src/ImageProcessorCore/Quantizers/Wu/WuQuantizer.cs   | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/ImageProcessorCore/Formats/Gif/GifEncoder.cs b/src/ImageProcessorCore/Formats/Gif/GifEncoder.cs
index 877931772..5fb3e4b8e 100644
--- a/src/ImageProcessorCore/Formats/Gif/GifEncoder.cs
+++ b/src/ImageProcessorCore/Formats/Gif/GifEncoder.cs
@@ -131,7 +131,7 @@ namespace ImageProcessorCore.Formats
         private QuantizedImage WriteColorTable(ImageBase image, Stream stream, int quality, int bitDepth)
         {
             // Quantize the image returning a palette.
-            QuantizedImage quantizedImage = this.Quantizer.Quantize(image, quality.Clamp(1, 255));
+            QuantizedImage quantizedImage = this.Quantizer.Quantize(image, quality);
 
             // Grab the palette and write it to the stream.
             Bgra32[] palette = quantizedImage.Palette;
@@ -162,6 +162,7 @@ namespace ImageProcessorCore.Formats
         /// </summary>
         /// <param name="image">The <see cref="ImageBase"/> to encode.</param>
         /// <param name="stream">The stream to write to.</param>
+        /// <param name="transparencyIndex">The index of the color in the color palette to make transparent.</param>
         private void WriteGraphicalControlExtension(ImageBase image, Stream stream, int transparencyIndex)
         {
             // TODO: Check transparency logic.
@@ -189,7 +190,7 @@ namespace ImageProcessorCore.Formats
 
             this.WriteByte(stream, packed);
             this.WriteShort(stream, extension.DelayTime);
-            this.WriteByte(stream, extension.TransparencyIndex);
+            this.WriteByte(stream, extension.TransparencyIndex == -1 ? 255 : extension.TransparencyIndex);
             this.WriteByte(stream, GifConstants.Terminator);
         }
 
diff --git a/src/ImageProcessorCore/Quantizers/Octree/Quantizer.cs b/src/ImageProcessorCore/Quantizers/Octree/Quantizer.cs
index 5ee54d762..3c66cc944 100644
--- a/src/ImageProcessorCore/Quantizers/Octree/Quantizer.cs
+++ b/src/ImageProcessorCore/Quantizers/Octree/Quantizer.cs
@@ -37,7 +37,7 @@ namespace ImageProcessorCore.Quantizers
         /// <summary>
         /// Gets or sets the transparency index.
         /// </summary>
-        public int TransparentIndex { get; protected set; }
+        public int TransparentIndex { get; protected set; } = -1;
 
         /// <inheritdoc/>
         public virtual QuantizedImage Quantize(ImageBase image, int maxColors)
diff --git a/src/ImageProcessorCore/Quantizers/Wu/WuQuantizer.cs b/src/ImageProcessorCore/Quantizers/Wu/WuQuantizer.cs
index 660e5e5af..9bb4e5f84 100644
--- a/src/ImageProcessorCore/Quantizers/Wu/WuQuantizer.cs
+++ b/src/ImageProcessorCore/Quantizers/Wu/WuQuantizer.cs
@@ -715,7 +715,7 @@ namespace ImageProcessorCore.Quantizers
         {
             List<Bgra32> pallette = new List<Bgra32>();
             byte[] pixels = new byte[image.Width * image.Height];
-            int transparentIndex = 0;
+            int transparentIndex = -1;
 
             for (int k = 0; k < colorCount; k++)
             {