Blur Image

<name>-blurred.webp

--overwrite

Critical Rules

which magick

--overwrite

-quality 85

magick identify

Flags

--guided

--overwrite

-blurred

--solid

-fill black -colorize 100

--dry-run

Phase 1: Preflight

1. Run

   which magick

   . If missing, show install instructions and stop:
   • macOS:

     brew install imagemagick

   • Ubuntu/Debian:

     sudo apt install imagemagick

   • Other: https://imagemagick.org/script/download.php
2. Run

   magick identify -format '%wx%h\n' image.png

   — this validates the file exists, format is supported (png, jpg, jpeg, webp, tiff), and returns pixel dimensions in one step. If the command outputs multiple lines, the image is animated (GIF, animated WebP, APNG) — stop and tell the user, because

   -region

   blur only affects the first frame
3. Report dimensions to confirm the coordinate space — Retina/HiDPI screenshots may be 2x logical resolution

Phase 2: Identify Regions

Mode A — Auto-detect (default)

1. Read the image using multimodal vision
2. Identify regions containing sensitive text:
   • Email addresses
   • API keys, tokens, secrets
   • URLs with credentials or internal hostnames
   • Personal names, phone numbers
   • IP addresses
   • File paths with usernames
   • Passwords, database connection strings
3. For each region, determine the bounding box

   (x, y, width, height)

   in pixels from top-left origin (ImageMagick's coordinate system)
4. Add 30-50px padding to all sides of each detected region — AI spatial detection has 20-50px error margins. Clamp coordinates so regions don't extend past image edges (X >= 0, Y >= 0, X+W <= image width, Y+H <= image height)
5. Present findings:

   I found N regions with sensitive text:
   1. [description] at roughly (X, Y) — WxH (with padding)
   2. [description] at roughly (X, Y) — WxH (with padding)

6. Ask user to confirm which regions to blur
7. If no sensitive content found, report that and offer

   --guided

   mode

Mode B — User-guided (

--guided

or when user specifies what to blur)

1. User describes what to blur: "blur the email in the top right" or "blur everything below the header"
2. Read the image, locate the described content
3. Propose padded coordinates and ask user to confirm

Phase 3: Generate Command

magick input.png \
  -region WxH+X+Y -blur 0x20 \
  -region WxH+X+Y -blur 0x20 \
  -strip -quality 85 output-blurred.webp

--solid

magick input.png \
  -region WxH+X+Y -fill black -colorize 100 \
  -region WxH+X+Y -fill black -colorize 100 \
  -strip -quality 85 output-blurred.webp

• Default output filename:

  <original-name>-blurred.webp

  alongside the original (

  -strip

  removes EXIF metadata)
• Present the full command and output path before running
• Ask: "Run this command? The blurred image will be saved as [path]."

Phase 4: Execute and Verify

1. Run the command
2. Read the output image to verify blur was applied to the correct regions
3. If any text is still visible or wrong area was blurred, offer to adjust coordinates (increase padding or shift position) and re-run
4. Report success with the output file path

Example

User: blur the sensitive stuff in screenshot.png

Claude: I'm using the blur-image skill to identify and blur sensitive regions.

Preflight: magick found at /opt/homebrew/bin/magick (v7.1.2)
Image: screenshot.png (1920x1080 PNG)

I found 2 regions with sensitive text:
1. Email address "user@company.com" at roughly (430, 210) — 320x65px (with padding)
2. API key "sk_live_..." at roughly (80, 560) — 390x60px (with padding)

Blur both regions? [Y/n]

User: Y

Running:
  magick screenshot.png \
    -region 320x65+430+210 -blur 0x20 \
    -region 390x60+80+560 -blur 0x20 \
    -strip -quality 85 screenshot-blurred.webp

✓ Done. Saved to screenshot-blurred.webp
I've verified the output — both regions are blurred and surrounding content is intact.

Red Flags

• Running blur without showing the command first
• Using sigma < 10 (text may be recoverable with deblurring)
• Overwriting the original without

  --overwrite

  flag
• Blurring the entire image instead of specific regions
• Not reading the output image to verify the blur
• Using coordinates without adding padding
• Skipping

  magick identify

  to confirm image dimensions
• Not handling Retina/HiDPI resolution differences