How do I install the Resize Image skill?

Run npx skillmds add majiayu000/resize-image in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Resize Image safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: reads secrets. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Resize Image?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Resize Image free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Resize Image?

majiayu000 (@majiayu000) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Resize Image by majiayu000 — Agent Skill

Name: Resize Image
Rating: 4.2 (5 reviews)
Author: majiayu000

Resize Image

Resize images using ImageMagick when they are too large to view or process. Use this skill when you encounter an image file that exceeds token limits, is too large to read, or when you need to create a smaller version of an image for viewing.

majiayu000 82626f8 2 files · 3.7 KB Updated Sep 9, 2026 567 repo stars

File contents

Resize Image Skill

This skill allows you to resize images using ImageMagick's convert command when they are too large to view or process.

When to Use

When reading an image file fails due to token limits
When an image is too large to process
When you need to create a thumbnail or smaller version of an image
When a user provides a mockup or screenshot that's too large

Prerequisites

ImageMagick must be installed. Check with:

which convert || echo "ImageMagick not installed"

If not installed, suggest the user install it:

Ubuntu/Debian: sudo apt-get install imagemagick
macOS: brew install imagemagick

Instructions

Step 1: Check the original image size

identify "/path/to/image.png"

This shows dimensions and file size.

Step 2: Resize the image

Resize to a maximum width/height while maintaining aspect ratio:

convert "/path/to/original.png" -resize 800x600\> "/tmp/resized-image.png"

The \> flag ensures the image is only shrunk, never enlarged.

Common resize options:

-resize 800x600 - Fit within 800x600, maintain aspect ratio
-resize 50% - Scale to 50% of original size
-resize 400x - Set width to 400px, auto-calculate height
-resize x400 - Set height to 400px, auto-calculate width

Step 3: Reduce quality/colors for smaller file size (optional)

For PNG files, reduce colors:

convert "/path/to/original.png" -resize 800x600\> -colors 256 "/tmp/resized-image.png"

For JPEG files, reduce quality:

convert "/path/to/original.jpg" -resize 800x600\> -quality 80 "/tmp/resized-image.jpg"

Step 4: Read the resized image

# Verify the new size
ls -la /tmp/resized-image.png
identify /tmp/resized-image.png

Then use the Read tool to view the resized image:

Read /tmp/resized-image.png

Examples

Example 1: Resize a large mockup

# Check original size
identify "/mnt/c/Users/user/mockup.png"
# Output: mockup.png PNG 2400x1800 ...

# Resize to fit within 800x600
convert "/mnt/c/Users/user/mockup.png" -resize 800x600\> "/tmp/mockup-small.png"

# Verify
identify "/tmp/mockup-small.png"
# Output: mockup-small.png PNG 800x600 ...

Example 2: Create a thumbnail

convert "/path/to/screenshot.png" -resize 400x -colors 128 "/tmp/thumbnail.png"

Example 3: Batch resize multiple images

for img in /path/to/images/*.png; do
  convert "$img" -resize 800x600\> "/tmp/$(basename "$img")"
done

Output Location

Always save resized images to /tmp/ with a descriptive name:

/tmp/resized-mockup.png
/tmp/thumbnail-screenshot.png
/tmp/small-diagram.png

Troubleshooting

"convert: command not found" ImageMagick is not installed. Ask the user to install it.

"convert: unable to open image" Check the file path. Windows paths under WSL should use /mnt/c/... format.

Image still too large after resize Try reducing colors or quality, or resize to smaller dimensions.

---name: resize-imagedescription: Resize images using ImageMagick when they are too large to view or process. Use this skill when you encounter an image file that exceeds token limits, is too large to read, or when you need to create a smaller version of an image for viewing.--- # Resize Image Skill This skill allows you to resize images using ImageMagick's `convert` command when they are too large to view or process. ## When to Use - When reading an image file fails due to token limits - When an image is too large to process - When you need to create a thumbnail or smaller version of an image - When a user provides a mockup or screenshot that's too large ## Prerequisites ImageMagick must be installed. Check with: ```bash which convert || echo "ImageMagick not installed" ``` If not installed, suggest the user install it: - Ubuntu/Debian: `sudo apt-get install imagemagick` - macOS: `brew install imagemagick` ## Instructions ### Step 1: Check the original image size ```bash identify "/path/to/image.png" ``` This shows dimensions and file size. ### Step 2: Resize the image Resize to a maximum width/height while maintaining aspect ratio: ```bash convert "/path/to/original.png" -resize 800x600\> "/tmp/resized-image.png" ``` The `\>` flag ensures the image is only shrunk, never enlarged. Common resize options: - `-resize 800x600` - Fit within 800x600, maintain aspect ratio - `-resize 50%` - Scale to 50% of original size - `-resize 400x` - Set width to 400px, auto-calculate height - `-resize x400` - Set height to 400px, auto-calculate width ### Step 3: Reduce quality/colors for smaller file size (optional) For PNG files, reduce colors: ```bash convert "/path/to/original.png" -resize 800x600\> -colors 256 "/tmp/resized-image.png" ``` For JPEG files, reduce quality: ```bash convert "/path/to/original.jpg" -resize 800x600\> -quality 80 "/tmp/resized-image.jpg" ``` ### Step 4: Read the resized image ```bash # Verify the new size ls -la /tmp/resized-image.png identify /tmp/resized-image.png ``` Then use the Read tool to view the resized image: ``` Read /tmp/resized-image.png ``` ## Examples ### Example 1: Resize a large mockup ```bash # Check original size identify "/mnt/c/Users/user/mockup.png" # Output: mockup.png PNG 2400x1800 ... # Resize to fit within 800x600 convert "/mnt/c/Users/user/mockup.png" -resize 800x600\> "/tmp/mockup-small.png" # Verify identify "/tmp/mockup-small.png" # Output: mockup-small.png PNG 800x600 ... ``` ### Example 2: Create a thumbnail ```bash convert "/path/to/screenshot.png" -resize 400x -colors 128 "/tmp/thumbnail.png" ``` ### Example 3: Batch resize multiple images ```bash for img in /path/to/images/*.png; do convert "$img" -resize 800x600\> "/tmp/$(basename "$img")" done ``` ## Output Location Always save resized images to `/tmp/` with a descriptive name: - `/tmp/resized-mockup.png` - `/tmp/thumbnail-screenshot.png` - `/tmp/small-diagram.png` ## Troubleshooting **"convert: command not found"** ImageMagick is not installed. Ask the user to install it. **"convert: unable to open image"** Check the file path. Windows paths under WSL should use `/mnt/c/...` format. **Image still too large after resize** Try reducing colors or quality, or resize to smaller dimensions.

Frequently asked questions