fixup #2, fix #1

- #2, #2 (comment)
- #1, tune the contrast and make script for generate variants automatic

.gitignore

@@ -1 +1,3 @@
 ~$*.pptx
+.tmp
+rust-memory-container-cs.png

generate-variants.sh

@@ -0,0 +1,54 @@
+#!/bin/sh
+# Requirement: `convert` command of ImageMagick
+
+ORIGINAL_PREFIX="rust-memory-container-cs"
+ORIGINAL_RESOLUTION="3840x2160"
+VARIANT_RESOLUTIONS=( "1920x1080" "1280x720" "192x108" )
+
+make_original_filename()
+{
+ # OUT
+ ORIGINAL_FILENAME="${ORIGINAL_PREFIX}.png"
+ echo $ORIGINAL_FILENAME
+}
+
+make_variant_filename()
+{
+ # IN
+ VARIANT_RESOLUTION=$1
+ VARIANT_SUFFIX=$2
+ # OUT
+ mkdir -p ${VARIANT_RESOLUTION}
+ VARIANT_FILENAME="${VARIANT_RESOLUTION}/${ORIGINAL_PREFIX}-${VARIANT_RESOLUTION}-${VARIANT_SUFFIX}.png"
+ echo $VARIANT_FILENAME
+}
+
+make_variants()
+{
+ # IN
+ VARIANT_OPTIONS=$1
+ VARIANT_SUFFIX=$2
+ # TMP
+ ORIGINAL_FILENAME=$(make_original_filename)
+ VARIANT_FILENAME_0=$(make_variant_filename $ORIGINAL_RESOLUTION $VARIANT_SUFFIX)
+ echo "[${ORIGINAL_RESOLUTION}] convert $ORIGINAL_FILENAME $VARIANT_OPTIONS $VARIANT_FILENAME_0"
+ convert $ORIGINAL_FILENAME $VARIANT_OPTIONS $VARIANT_FILENAME_0
+ for VARIANT_RESOLUTION_N in "${VARIANT_RESOLUTIONS[@]}"
+ do
+  VARIANT_FILENAME_N=$(make_variant_filename $VARIANT_RESOLUTION_N $VARIANT_SUFFIX)
+  echo "[${VARIANT_RESOLUTION_N}] convert $VARIANT_FILENAME_0 -resize $VARIANT_RESOLUTION_N $VARIANT_FILENAME_N"
+  convert $VARIANT_FILENAME_0 -resize $VARIANT_RESOLUTION_N $VARIANT_FILENAME_N
+ done
+}
+
+make_variants "-define modulate:colorspace=HSL" "dark-back"
+make_variants "+contrast -modulate 50" "dark-back-low-contrast"
+make_variants "-contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -modulate 100" "dark-back-high-contrast"
+make_variants "-contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -modulate 200 -monochrome" "black-back-white-ink"
+make_variants "-contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -modulate 200 -monochrome -negate" "white-back-black-ink"
+make_variants "-channel RGB -negate -define modulate:colorspace=HSL -modulate 100,100,0" "light-back"
+make_variants "-channel RGB -negate -define modulate:colorspace=HSL -modulate 100,50,0" "light-back-low-contrast"
+make_variants "-channel RGB -negate -define modulate:colorspace=HSL -modulate 75,800,0 -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -contrast -define modulate:colorspace=RGB" "light-back-high-contrast"
+make_variants "+contrast +contrast -modulate 150" "grey-back"
+make_variants "+contrast +contrast -modulate 150 +contrast +contrast +contrast -modulate 50" "grey-back-low-contrast"
+make_variants "+contrast +contrast -modulate 150 -define modulate:colorspace=HSL -modulate 100,400,100" "grey-back-high-contrast"