From ead5bed24e07383fbcf783c3b5c70a755dbc1982 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Sat, 18 Jan 2020 15:57:10 +0100
Subject: [PATCH] thumb: strip metadata and chroma

Decreased colour quality recommended by Google PageSpeed:
<https://developers.google.com/speed/docs/insights/OptimizeImages>
---
 thumb/index.php | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/thumb/index.php b/thumb/index.php
index c65cab3..d296fbf 100644
--- a/thumb/index.php
+++ b/thumb/index.php
@@ -91,6 +91,8 @@ function mkthumb_exec($source, $target, $width, $height)
 		'-trim',
 		'-background', 'white', '-layers', 'flatten', # opaque
 		'-interlace', 'plane', # progressive
+		'-strip', '-taint', # omit metadata
+		'-sampling-factor', '4:2:0', '-colorspace', 'sRGB', # half chroma
 		'-resize', "${width}x${height}",
 		'-quality', '85%',
 		$source, "jpg:$target"
-- 
2.30.0