From f1d0d364c4dfe2e2a11eb1e34d6c620f2c0bf8f2 Mon Sep 17 00:00:00 2001
From: Ryan Schmidt <skizzerz@skizzerz.net>
Date: Thu, 19 Apr 2018 10:00:16 -0700
Subject: [PATCH] Add $wgJpegQuality to control jpg thumb quality

This new configuration variable defaults to 80, which is the current
quality in use when scaling jpeg thumbnails with ImageMagick. GD used a
quality of 95, which was reduced to 80 as a result of this change.

Bug: T192248
Change-Id: I94cad01cc876ef9083250f5d1989a73cd19617fb
---
 RELEASE-NOTES-1.32           |  2 ++
 includes/DefaultSettings.php |  9 +++++++++
 includes/media/Bitmap.php    | 23 +++++++++++++++++------
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/RELEASE-NOTES-1.32 b/RELEASE-NOTES-1.32
index 7971bccdf1..9eb751a049 100644
--- a/RELEASE-NOTES-1.32
+++ b/RELEASE-NOTES-1.32
@@ -9,6 +9,8 @@ production.
 * (T115414) The $wgEnableAPI and $wgEnableWriteAPI settings, deprecated in 1.31, have been removed.
 * The $wgUseAjax setting is now formally deprecated, and MediaWiki will act as if it is always set.
 * The $wgSiteSupportPage setting, unused since 1.5, was removed.
+* $wgJpegQuality was added to allow configuring the quality of JPEG thumbnails (default 80).
+* The default quality of JPEG thumbnails generated by GD was reduced from 95 to 80.
 * …
 
 === New features in 1.32 ===
diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 1ea9a420d8..975e20a463 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -1085,6 +1085,15 @@ $wgJpegTran = '/usr/bin/jpegtran';
  */
 $wgJpegPixelFormat = 'yuv420';
 
+/**
+ * When scaling a JPEG thumbnail, this is the quality we request
+ * from the backend. It should be an int between 1 and 100,
+ * with 100 indicating 100% quality.
+ *
+ * @since 1.32
+ */
+$wgJpegQuality = 80;
+
 /**
  * Some tests and extensions use exiv2 to manipulate the Exif metadata in some
  * image formats.
diff --git a/includes/media/Bitmap.php b/includes/media/Bitmap.php
index b88a34dcad..cda037c16d 100644
--- a/includes/media/Bitmap.php
+++ b/includes/media/Bitmap.php
@@ -134,7 +134,8 @@ class BitmapHandler extends TransformationalImageHandler {
 	protected function transformImageMagick( $image, $params ) {
 		# use ImageMagick
 		global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
-			$wgImageMagickTempDir, $wgImageMagickConvertCommand, $wgJpegPixelFormat;
+			$wgImageMagickTempDir, $wgImageMagickConvertCommand, $wgJpegPixelFormat,
+			$wgJpegQuality;
 
 		$quality = [];
 		$sharpen = [];
@@ -146,7 +147,7 @@ class BitmapHandler extends TransformationalImageHandler {
 
 		if ( $params['mimeType'] == 'image/jpeg' ) {
 			$qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
-			$quality = [ '-quality', $qualityVal ?: '80' ]; // 80%
+			$quality = [ '-quality', $qualityVal ?: (string)$wgJpegQuality ]; // 80% by default
 			if ( $params['interlace'] ) {
 				$animation_post = [ '-interlace', 'JPEG' ];
 			}
@@ -276,7 +277,7 @@ class BitmapHandler extends TransformationalImageHandler {
 	 */
 	protected function transformImageMagickExt( $image, $params ) {
 		global $wgSharpenReductionThreshold, $wgSharpenParameter, $wgMaxAnimatedGifArea,
-			$wgJpegPixelFormat;
+			$wgJpegPixelFormat, $wgJpegQuality;
 
 		try {
 			$im = new Imagick();
@@ -293,7 +294,7 @@ class BitmapHandler extends TransformationalImageHandler {
 					$im->sharpenImage( $radius, $sigma );
 				}
 				$qualityVal = isset( $params['quality'] ) ? (string)$params['quality'] : null;
-				$im->setCompressionQuality( $qualityVal ?: 80 );
+				$im->setCompressionQuality( $qualityVal ?: $wgJpegQuality );
 				if ( $params['interlace'] ) {
 					$im->setInterlaceScheme( Imagick::INTERLACE_JPEG );
 				}
@@ -498,9 +499,19 @@ class BitmapHandler extends TransformationalImageHandler {
 
 	/**
 	 * Callback for transformGd when transforming jpeg images.
+	 *
+	 * @param resource $dst_image Image resource of the original image
+	 * @param string $thumbPath File path to write the thumbnail image to
+	 * @param int|null $quality Quality of the thumbnail from 1-100,
+	 *    or null to use default quality.
 	 */
-	// FIXME: transformImageMagick() & transformImageMagickExt() uses JPEG quality 80, here it's 95?
-	static function imageJpegWrapper( $dst_image, $thumbPath, $quality = 95 ) {
+	static function imageJpegWrapper( $dst_image, $thumbPath, $quality = null ) {
+		global $wgJpegQuality;
+
+		if ( $quality === null ) {
+			$quality = $wgJpegQuality;
+		}
+
 		imageinterlace( $dst_image );
 		imagejpeg( $dst_image, $thumbPath, $quality );
 	}
-- 
2.20.1