Externalize image optim to a script

Makefile

@@ -137,22 +137,23 @@ gemini: $(DST_GMI_FILES) $(GMI_INDEX) $(GEM_ATOM)
 # Images
 SRC_IMG_FILES ?= $(shell find $(SRC_DIR) -type f -name "*.jpg" -or -name "*.jpeg" -or -name "*.gif" -or -name "*.png")
 DST_IMG_FILES ?= $(patsubst $(SRC_DIR)/%,$(DST_DIR)/%, $(SRC_IMG_FILES))
+OPTIM_IMG := engine/optim-img.sh
 
-$(DST_DIR)/%.jpg: $(SRC_DIR)/%.jpg
+$(DST_DIR)/%.jpg: $(SRC_DIR)/%.jpg $(OPTIM_IMG)
 	@mkdir -p $(dir $@)
-	convert "$<" -quality 50 -resize 800x800\> "$@"
+	$(OPTIM_IMG) "$<" "$@"
 
-$(DST_DIR)/%.jpg: $(SRC_DIR)/%.jpeg
+$(DST_DIR)/%.jpg: $(SRC_DIR)/%.jpeg $(OPTIM_IMG)
 	@mkdir -p $(dir $@)
-	convert "$<" -quality 50 -resize 800x800\> "$@"
+	$(OPTIM_IMG) "$<" "$@"
 
-$(DST_DIR)/%.gif: $(SRC_DIR)/%.gif
+$(DST_DIR)/%.gif: $(SRC_DIR)/%.gif $(OPTIM_IMG)
 	@mkdir -p $(dir $@)
-	convert "$<" -quality 50 -resize 800x800\> "$@"
+	$(OPTIM_IMG) "$<" "$@"
 
-$(DST_DIR)/%.png: $(SRC_DIR)/%.png
+$(DST_DIR)/%.png: $(SRC_DIR)/%.png $(OPTIM_IMG)
 	@mkdir -p $(dir $@)
-	convert "$<" -quality 50 -resize 800x800\> "$@"
+	$(OPTIM_IMG) "$<" "$@"
 
 .PHONY: img
 img: $(DST_IMG_FILES)

engine/optim-img.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env zsh
+
+src="$1"
+dst="$2"
+convert "$src" -quality 50 -resize 800x800\> "$dst"
+
+# mogrify -path "$dst" \
+#     -filter Triangle \
+#     -define filter:support=2 \
+#     -thumbnail 800 \
+#     -unsharp 0.25x0.25+8+0.065 \
+#     -dither None \
+#     -posterize 136 \
+#     -quality 82 \
+#     -define jpeg:fancy-upsampling=off \
+#     -define png:compression-filter=5 \
+#     -define png:compression-level=9 \
+#     -define png:compression-strategy=1 \
+#     -define png:exclude-chunk=all \
+#     -interlace none \
+#     -colorspace sRGB \
+#     -strip "$src"