[UI] Minor improvements to create_deluge_pngs

Change the default compression tool to oxipng since it produces smaller
files faster than zopfli.

Add the ECT tool as an option to get maximum compression but is quite
slow to complete.

deluge/scripts/create_deluge_pngs

@@ -1,11 +1,26 @@
 #!/bin/bash
-
-# A script to convert the Deluge svg icons to png.
+# Convert Deluge svg icons to png.
+#
+# Requires
+#  * rsvg-convert
+#  * convert (ImageMagik)
+#  * oxipng
+#
+# Optional
+#  * ect (Efficient-Compression-Tool)
+#
+# Potential to combine pngquant with oxipng for further gains.
+#
+# Excellent compression with ECT but is much slower. For Linux need
+# to build this tool from source.
 
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 data_dir="$DIR/../ui/data"
-zopfli_iter="--iterations=100"
-zopflipng_bin="zopflipng --filters=01234mepb --lossy_8bit --lossy_transparent -y"
+
+OXI_COMPRESS="oxipng --opt 4 --interlace 0 --strip safe"
+ECT_COMPRESS="ect --allfilters-b --pal_sort=120 -30060"
+
+COMPRESS=$OXI_COMPRESS
 
 # Create deluge png icon pack for all sizes.
 for size in 16 22 24 32 36 48 64 72 96 128 192 256 512; do
@@ -13,11 +28,7 @@ for size in 16 22 24 32 36 48 64 72 96 128 192 256 512; do
     in_svg=$data_dir/pixmaps/deluge.svg
     out_png=$data_dir/icons/hicolor/${size}x${size}/apps/deluge.png
     rsvg-convert -w ${size} -h ${size} -o $out_png $in_svg
-    if [ "$size" -gt 128 ]; then
-        zopfli_iter=""
-    fi
-    echo $zopflipng_bin $zopfli_iter
-    eval $zopflipng_bin $zopfli_iter $out_png $out_png
+    eval $COMPRESS $out_png
 done
 
 # Create deluge-panel png for systray.
@@ -44,7 +55,7 @@ cp $data_dir/icons/hicolor/48x48/apps/deluge.png $data_dir/pixmaps/deluge.png
 for file in $data_dir/pixmaps/*.svg; do
     out_png=${file%.*}16.png
     rsvg-convert -w 16 -h 16 -o $out_png $file
-    eval $zopflipng_bin $out_png $out_png
+    eval $COMPRESS $out_png
 done
 
 # Copy 16px deluge and status pngs to webui icons folder.
@@ -58,11 +69,12 @@ for size in 32 192 512; do
     in_png=$data_dir/icons/hicolor/${size}x${size}/apps/deluge.png
     out_png=$data_dir/../web/icons/deluge-${size}.png
     cp $in_png $out_png
+done
 
 # Create apple and android touch icons with background colour.
 apple_icon=$data_dir/../web/icons/deluge-apple-180.png
 rsvg-convert -w 180 -h 180 -b '#599EEE' -o $apple_icon $data_dir/pixmaps/deluge.svg
-eval $zopflipng_bin $apple_icon $apple_icon
+eval $COMPRESS $apple_icon
 
 # Create favicon.ico icon from pngs.
 for size in 16 32 48; do