u-claw/portable/skills/en/image-compress/SKILL.md

name, description, metadata

name	description	metadata
image-compress	Image compression and conversion - shrink, resize, convert jpg/png/webp. Runs locally.	openclaw emoji 🖼️

Image Compression / Conversion

Shrink image file sizes, change dimensions, convert between formats. Everything runs on this machine — photos are never uploaded.

What it does

• Compress: reduce file size by quality or resolution, for email and messaging
• Resize: scale by dimension or percentage
• Convert: jpg / png / webp (webp is usually smallest)
• Batch: process a whole folder

How to run it

Use the Bash tool with Python's Pillow — cross-platform and entirely local.

python -c "import PIL" 2>/dev/null || pip install -q Pillow

# Single image: quality 75, cap width at 1600px, keep aspect ratio
python - <<'PY'
from PIL import Image
im = Image.open("input.jpg")
if im.width > 1600:
    im = im.resize((1600, int(im.height * 1600 / im.width)))
im.convert("RGB").save("output.jpg", "JPEG", quality=75, optimize=True)
print("compressed -> output.jpg")
PY

# Batch: every jpg/png in this folder -> webp
python - <<'PY'
from PIL import Image
import glob, os
for f in glob.glob("*.jpg") + glob.glob("*.png"):
    out = os.path.splitext(f)[0] + ".webp"
    Image.open(f).save(out, "WEBP", quality=80)
    print(f"{f} -> {out}")
PY

Working notes

• Run ls -lh before and after, and tell the user how much was actually saved
• Never overwrite the original unless the user explicitly asks — write a new file
• PNG transparency is lost when converting to JPG but survives in webp; pick the format based on whether the image has an alpha channel