From da992a7bdd16dc7886e011b8791c2c7dd8302d6f Mon Sep 17 00:00:00 2001
From: Uwe Steinmann <steinm@debian.org>
Date: Sat, 11 Mar 2023 18:59:02 +0100
Subject: [PATCH] create 8-bit png instead of 16-bit

---
 inc/inc.ClassConversionServicePdfToImage.php | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/inc/inc.ClassConversionServicePdfToImage.php b/inc/inc.ClassConversionServicePdfToImage.php
index 4a7f1ce2e..c7b178765 100644
--- a/inc/inc.ClassConversionServicePdfToImage.php
+++ b/inc/inc.ClassConversionServicePdfToImage.php
@@ -65,9 +65,14 @@ class SeedDMS_ConversionServicePdfToImage extends SeedDMS_ConversionServiceBase
 				if(!empty($params['width']))
 					$imagick->scaleImage(min((int) $params['width'], $imagick->getImageWidth()), 0);
 				/* Remove alpha channel and set to white */
-        $imagick->setImageBackgroundColor('white');
-        $imagick->setImageAlphaChannel(Imagick::ALPHACHANNEL_REMOVE);
-        $imagick->mergeImageLayers(Imagick::LAYERMETHOD_FLATTEN);
+				$imagick->setImageBackgroundColor('white');
+				/* Setting the color-type and bit-depth produces much smaller images
+				 * because the default depth appears to be 16 bit
+				 */
+				$imagick->setOption('png:color-type', 6);
+				$imagick->setOption('png:bit-depth', 8);
+				$imagick->setImageAlphaChannel(Imagick::ALPHACHANNEL_REMOVE);
+				$imagick->mergeImageLayers(Imagick::LAYERMETHOD_FLATTEN);
 				$imagick->setImageFormat('png');
 				$end = microtime(true);
 				if($this->logger) {