Trim

Automatically trim/remove boring border edges from images. Perfect for removing whitespace, borders, uniform backgrounds, or padding from scanned documents and screenshots.

Installation

To install the Image plugin:

Terminal

$ npm install -g @mediaproc/image

Usage

Terminal

$ mediaproc image trim <input> [options]

Basic Usage

Terminal

$ mediaproc image trim photo.jpg

✓ Trimmed borders (threshold: 10)

$ mediaproc image trim image.png -t 5

$ mediaproc image trim pic.jpg -t 20

$ mediaproc image trim "scans/*.jpg" -t 15

Options

Option	Alias	Type	Default	Description
`--threshold <value>`	`-t`	number	`10`	Edge detection threshold (1-100)
`--output <path>`	`-o`	string	-	Output file path (default: `<input>-trimmed.<ext>`)
`--quality <quality>`	`-q`	number	`90`	Output quality (1-100)
`--dry-run`		boolean	`false`	Preview without making changes
`--verbose`	`-v`	boolean	`false`	Show detailed output
`--help`		boolean	`false`	Display help information

Threshold Guide

Threshold	Sensitivity	Use Case
1-5	Very sensitive	Subtle edges, slight color differences
5-10	Sensitive	Minor borders, light padding
10	Balanced (default)	General purpose trimming
15-20	Aggressive	Obvious borders, thick padding
20-30	Very aggressive	Strong borders, may over-trim
30+	Extreme	Maximum trimming, risk of over-trimming

Choosing Threshold

Lower threshold (1-10):

More sensitive to color differences
Removes subtle edges
Preserves more of the image
Use for: Light borders, subtle padding

Higher threshold (10-25):

Less sensitive, more aggressive
Removes obvious borders
May trim important content
Use for: Thick borders, screenshots

Examples

1. Default Trim

Balanced automatic trim:

mediaproc image trim document.jpg

Result: Removes obvious borders

2. Gentle Trim

Sensitive edge detection:

mediaproc image trim photo.png -t 5

Subtle: Remove slight edges

3. Aggressive Trim

Remove thick borders:

mediaproc image trim scan.jpg -t 20

Strong: Maximum border removal

4. Screenshot Cleanup

Remove screenshot padding:

mediaproc image trim screenshot.png -t 15

Screenshots: Clean padding removal

5. Scanned Document

Clean scan borders:

mediaproc image trim scanned-page.jpg -t 12 -o clean-page.jpg

Documents: Professional appearance

6. Product Photo

Remove white background edges:

mediaproc image trim product.jpg -t 8

Products: Clean product edges

7. Batch Scan Processing

Process multiple scans:

mediaproc image trim "scans/*.jpg" -t 15

Batch: Consistent trimming

8. Whiteboard Photo

Trim whiteboard edges:

mediaproc image trim whiteboard.jpg -t 18

Whiteboards: Remove wall/edges

9. Art Scan

Preserve artwork, remove borders:

mediaproc image trim artwork-scan.png -t 10 -q 100

Artwork: High-quality trim

10. Business Card

Trim business card scan:

mediaproc image trim business-card.jpg -t 12

Cards: Clean edges

11. Verbose Trim

See processing details:

mediaproc image trim document.jpg -t 10 --verbose

Info: Threshold confirmation

12. Preview Trim

Check before processing:

mediaproc image trim photo.jpg -t 15 --dry-run

Safety: Verify output path

13. Logo Cleanup

Remove logo borders:

mediaproc image trim logo.png -t 5 -o clean-logo.png

Logos: Clean transparent edges

14. PDF Page Scan

Trim PDF page scan:

mediaproc image trim pdf-page.jpg -t 20

PDFs: Remove scan margins

15. Certificate Scan

Clean certificate edges:

mediaproc image trim certificate.jpg -t 15 -q 95

Certificates: Professional presentation

Use Cases

1. Scanned Documents

Remove scan borders and margins:

# Clean document scans
mediaproc image trim document-scan.jpg -t 15

# Remove scanner bed edges

Document Scanning: Professional clean docs

2. Screenshot Cleanup

Remove desktop/browser padding:

# Screenshot with borders
mediaproc image trim screenshot.png -t 18

# Clean application view

Screenshots: Clean content capture

3. Product Photography

Remove white background edges:

# Product on white background
mediaproc image trim product.jpg -t 10

# Clean product boundaries

E-commerce: Clean product images

4. Whiteboard/Chalkboard Photos

Trim board edges:

# Whiteboard meeting notes
mediaproc image trim whiteboard.jpg -t 20

# Remove wall/board edges

Meetings: Clean notes capture

5. Business Cards

Clean business card scans:

# Scanned business card
mediaproc image trim business-card.jpg -t 12

# Remove scan background

Networking: Professional card images

6. Art/Drawings

Trim artwork scan borders:

# Drawing scan
mediaproc image trim drawing.png -t 10 -q 100

# Preserve artwork quality

Art: Clean artwork presentation

7. Receipt Scanning

Clean receipt edges:

# Receipt photo
mediaproc image trim receipt.jpg -t 15

# Remove surface/background

Expenses: Clean expense records

8. Book Page Scanning

Trim book page edges:

# Scanned book page
mediaproc image trim book-page.jpg -t 12

# Remove book edges/background

Books: Clean page capture

9. Certificate Scanning

Professional certificate presentation:

# Scanned certificate
mediaproc image trim certificate.jpg -t 15 -q 95

# Clean borders

Certificates: Presentable documents

10. Logo Extraction

Extract logos from backgrounds:

# Logo with border
mediaproc image trim logo.png -t 8

# Clean logo edges

Branding: Clean logo files

Combining with Other Commands

Trim + Crop

Trim then precise crop:

# Auto-trim borders
mediaproc image trim scan.jpg -t 15 -o trimmed.jpg

# Then precise crop
mediaproc image crop trimmed.jpg --width 2000 --height 1500

Precision: Automated then manual

Rotate + Trim

Straighten then trim:

# Rotate if skewed
mediaproc image rotate scan.jpg -a 2 -o straight.jpg

# Trim rotated edges
mediaproc image trim straight.jpg -t 15

Straightening: Clean aligned image

Trim + Threshold

Trim then binarize:

# Trim borders
mediaproc image trim document.jpg -t 15 -o trimmed.jpg

# Convert to black/white
mediaproc image threshold trimmed.jpg -t 180

Documents: Clean binary documents

Adjust + Trim

Enhance then trim:

# Increase contrast
mediaproc image linear photo.jpg -a 1.2 -o enhanced.jpg

# Trim edges
mediaproc image trim enhanced.jpg -t 10

Enhancement: Better edge detection

Trim + Border

Trim then add new border:

# Remove old border
mediaproc image trim image.jpg -t 15 -o clean.jpg

# Add custom border
mediaproc image border clean.jpg --width 10 --color black

Reframing: Replace borders

Batch Trim + Resize

Clean then standardize:

# Trim all
mediaproc image trim "scans/*.jpg" -t 15

# Then resize
mediaproc image resize "*-trimmed.jpg" -w 2000

Workflow: Consistent output

Technical Details

Trim Algorithm

Process:

Analyze image edges
Detect uniform/boring regions
Compare pixels to edge color
If difference < threshold: trim
Remove detected border pixels
Output trimmed image

Edge Detection:

Starts from image edges (top, bottom, left, right)
Compares adjacent pixels
Removes pixels within threshold of edge color
Stops when variation exceeds threshold

Threshold Behavior

Low threshold (1-10):

Requires very similar colors to trim
Stops at subtle color changes
Preserves more content

High threshold (15-30):

Tolerates larger color differences
Trims more aggressively
Risk of removing wanted content

Formula:

If |pixel_color - edge_color| < threshold: trim pixel

Performance

Very fast: ~30-100ms per image
Small images: ~30-50ms
Large images (4K): ~80-150ms
Minimal memory usage
Efficient edge detection

Precision

Pixel-perfect edge detection
Independent per side (top/bottom/left/right)
Non-destructive to image content
Maintains aspect ratio changes

Best Practices

1. Start with Default

Try default threshold first:

# Default (10) is usually good
mediaproc image trim document.jpg

2. Adjust Based on Results

Increase or decrease based on outcome:

# Too much trimmed? Lower threshold
mediaproc image trim image.jpg -t 5

# Not enough? Raise threshold
mediaproc image trim image.jpg -t 20

3. Consistent Threshold for Batch

Use same threshold for similar images:

# Consistent results
mediaproc image trim "scans/*.jpg" -t 15

4. Test on Sample First

Try one image before batch:

# Test first
mediaproc image trim sample.jpg -t 15

# If good, process all
mediaproc image trim "all/*.jpg" -t 15

5. Higher Threshold for Obvious Borders

Screenshots, thick borders need higher values:

# Screenshots usually need 15-20
mediaproc image trim screenshot.png -t 18

6. Lower Threshold for Subtle Edges

Gentle trim for subtle borders:

# Subtle borders need 5-10
mediaproc image trim photo.png -t 7

7. Preserve Quality

Use high quality for important images:

# Maximum quality
mediaproc image trim artwork.png -t 10 -q 100

Troubleshooting

Issue: Trimmed Too Much

Problem: Important content removed

Cause: Threshold too high

Solution: Lower threshold value

# Reduce threshold
mediaproc image trim image.jpg -t 5

Issue: Nothing Trimmed

Problem: No visible trimming

Cause: Threshold too low or no uniform edges

Solution: Increase threshold or image has no borders

# Try higher threshold
mediaproc image trim image.jpg -t 20

# Or image may not have borders to trim

Issue: Uneven Trim

Problem: Some sides trimmed, others not

Cause: Non-uniform borders

Solution: This is correct behavior

# Trim only removes uniform edges
# Non-uniform borders won't trim evenly

Issue: Still Has Small Border

Problem: Thin border remains

Cause: Threshold not high enough

Solution: Increase threshold slightly

# Slightly higher
mediaproc image trim image.jpg -t 12

Issue: Over-Trimming on One Side

Problem: One side trimmed too aggressively

Cause: That side has more uniform color

Solution: This is expected; trim is per-side

# Independent per side
# Each edge evaluated separately

Issue: Content at Edges Removed

Problem: Wanted content near edges removed

Cause: Content too similar to border color

Solution: Lower threshold or manually crop instead

# Lower threshold
mediaproc image trim image.jpg -t 5

# Or use manual crop
mediaproc image crop image.jpg --width 2000 --height 1500

crop - Manual precise cropping
rotate - Straighten before trimming
border - Add borders after trimming
threshold - Binarize after trimming
auto-orient - Orient before trimming