Use 90% JPEG quality for thumbnails and previews by default

Signed-off-by: Joas Schilling <coding@schilljs.com>

lib/private/legacy/image.php

@@ -54,6 +54,8 @@ class OC_Image implements \OCP\IImage {
 	private $fileInfo;
 	/** @var \OCP\ILogger */
 	private $logger;
+	/** @var \OCP\IConfig */
+	private $config;
 	/** @var array */
 	private $exif;
 
@@ -79,12 +81,17 @@ class OC_Image implements \OCP\IImage {
 	 * @param resource|string $imageRef The path to a local file, a base64 encoded string or a resource created by
 	 * an imagecreate* function.
 	 * @param \OCP\ILogger $logger
+	 * @param \OCP\IConfig $config
 	 */
-	public function __construct($imageRef = null, $logger = null) {
+	public function __construct($imageRef = null, $logger = null, \OCP\IConfig $config = null) {
 		$this->logger = $logger;
 		if (is_null($logger)) {
 			$this->logger = \OC::$server->getLogger();
 		}
+		$this->config = $config;
+		if ($config === null) {
+			$this->config = \OC::$server->getConfig();
+		}
 
 		if (\OC_Util::fileInfoLoaded()) {
 			$this->fileInfo = new finfo(FILEINFO_MIME_TYPE);
@@ -267,7 +274,7 @@ class OC_Image implements \OCP\IImage {
 				$retVal = imagegif($this->resource, $filePath);
 				break;
 			case IMAGETYPE_JPEG:
-				$retVal = imagejpeg($this->resource, $filePath);
+				$retVal = imagejpeg($this->resource, $filePath, $this->getJpegQuality());
 				break;
 			case IMAGETYPE_PNG:
 				$retVal = imagepng($this->resource, $filePath);
@@ -319,7 +326,12 @@ class OC_Image implements \OCP\IImage {
 				$res = imagepng($this->resource);
 				break;
 			case "image/jpeg":
-				$res = imagejpeg($this->resource);
+				$quality = $this->getJpegQuality();
+				if ($quality !== null) {
+					$res = imagejpeg($this->resource, null, $quality);
+				} else {
+					$res = imagejpeg($this->resource);
+				}
 				break;
 			case "image/gif":
 				$res = imagegif($this->resource);
@@ -342,6 +354,17 @@ class OC_Image implements \OCP\IImage {
 		return base64_encode($this->data());
 	}
 
+	/**
+	 * @return int|null
+	 */
+	protected function getJpegQuality() {
+		$quality = $this->config->getAppValue('preview', 'jpeg_quality', 90);
+		if ($quality !== null) {
+			$quality = min(100, max(10, (int) $quality));
+		}
+		return $quality;
+	}
+
 	/**
 	 * (I'm open for suggestions on better method name ;)
 	 * Get the orientation based on EXIF data.

tests/lib/ImageTest.php

@@ -9,6 +9,7 @@
 namespace Test;
 
 use OC;
+use OCP\IConfig;
 
 class ImageTest extends \Test\TestCase {
 	public static function tearDownAfterClass() {
@@ -133,7 +134,12 @@ class ImageTest extends \Test\TestCase {
 		$expected = ob_get_clean();
 		$this->assertEquals($expected, $img->data());
 
-		$img = new \OC_Image(OC::$SERVERROOT.'/tests/data/testimage.jpg');
+		$config = $this->createMock(IConfig::class);
+		$config->expects($this->once())
+			->method('getAppValue')
+			->with('preview', 'jpeg_quality', 90)
+			->willReturn(null);
+		$img = new \OC_Image(OC::$SERVERROOT.'/tests/data/testimage.jpg', null, $config);
 		$raw = imagecreatefromstring(file_get_contents(OC::$SERVERROOT.'/tests/data/testimage.jpg'));
 		ob_start();
 		imagejpeg($raw);