Heads branding: add optimize_grayscale_bootsplash.sh and modify all Heads grayscale bootsplashes with it

branding/Heads/optimize_grayscale_bootsplash.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+
+# Function to check if an image is effectively grayscale
+is_effectively_grayscale() {
+    local image="$1"
+    local colors=$(identify -format "%k" "$image")
+    local type=$(identify -format "%r" "$image")
+    [[ "$type" == *"Gray"* ]] || [[ "$colors" -le 256 ]]
+}
+
+# Function to analyze the image
+analyze_image() {
+    local image="$1"
+    echo "Analyzing: $image"
+
+    identify -verbose "$image" | grep -E "Image:|Geometry:|Colorspace:|Type:|Depth:|Colors:|Filesize:"
+
+    echo "------------------------"
+}
+
+# Function to optimize the bootsplash image
+optimize_bootsplash() {
+    local input_image="$1"
+    local temp_image="${input_image}.temp"
+
+    convert "$input_image" \
+        -colorspace Gray \
+        -define jpeg:extent=20KB \
+        -quality 98 \
+        -dither Riemersma \
+        -strip \
+        "$temp_image"
+
+    mv "$temp_image" "$input_image"
+    echo "Optimized image: $input_image"
+}
+
+# Main script
+for input_image in *.jpg *.jpeg; do
+    # Check if the file exists
+    if [[ -f "$input_image" ]]; then
+        echo "Processing: $input_image"
+        analyze_image "$input_image"
+        if is_effectively_grayscale "$input_image"; then
+            echo "Optimizing effectively grayscale image: $input_image"
+            optimize_bootsplash "$input_image"
+            analyze_image "$input_image"
+        else
+            echo "Skipping non-grayscale image: $input_image"
+        fi
+    fi
+done