convert

Convert images between different formats with quality and compression control.

Usage

Terminal

$ mediaproc image convert <input> -f <format> [options]

Description

The convert command transforms images between different file formats, including modern formats like WebP and AVIF that offer superior compression and quality. This is essential for:

Web optimization: Convert to WebP/AVIF for smaller file sizes
Compatibility: Convert modern formats to legacy formats (JPG/PNG)
Workflow requirements: Match format to specific use cases
Print preparation: Convert to TIFF for professional printing
Format migration: Batch convert image libraries

Supports intelligent format-specific options like progressive rendering, compression levels, and quality settings tailored to each format's capabilities.

Modern Format Benefits

WebP and AVIF formats offer 25-50% better compression than JPEG while maintaining the same visual quality. WebP has excellent browser support (96%+), while AVIF is newer but offers even better compression. Always provide fallbacks for older browsers.

Options

Option	Type	Default	Description
`<input>`	string	required	Input image file path or glob pattern
`-f, --format`	string	`webp`	Output format: jpg, jpeg, png, webp, avif, tiff, gif
`-o, --output`	string	`<input>.<format>`	Output file path
`-q, --quality`	number	`90`	Output quality 1-100
`--compression`	number	`9`	PNG compression level 0-9 (0=none, 9=max)
`--progressive`	boolean	`false`	Use progressive/interlaced format
`--dry-run`	boolean	`false`	Show what would be done without processing
`-v, --verbose`	boolean	`false`	Enable verbose logging

Examples

Basic Format Conversion

Convert between formats:

Terminal

$ mediaproc image convert photo.jpg

✓ Converted to WebP • 2.4 MB → 1.1 MB

Terminal

$ mediaproc image convert image.png -f avif -o image.avif

✓ Converted to AVIF • 892 KB → 312 KB

Terminal

$ mediaproc image convert modern.webp -f jpg -o legacy.jpg

✓ Converted to JPEG

$ mediaproc image convert photo.jpg -f png -o photo.png

$ mediaproc image convert image.jpg -f tiff -o print_ready.tiff

$ mediaproc image convert image.png -f gif -o animation.gif

Quality Control

Adjust output quality:

Terminal

$ mediaproc image convert photo.jpg -f webp -q 95 -o high_quality.webp

✓ Converted • Quality: 95 • Size: 2.8 MB

Terminal

$ mediaproc image convert image.png -f jpg -q 90 -o standard.jpg

✓ Converted • Quality: 90 • Size: 1.2 MB

Terminal

$ mediaproc image convert photo.jpg -f avif -q 80 -o medium.avif

✓ Converted • Quality: 80 • Size: 420 KB

$ mediaproc image convert image.jpg -f webp -q 70 -o compressed.webp

$ mediaproc image convert photo.png -f jpg -q 60 -o low_quality.jpg

PNG Compression

Control PNG compression levels:

# Maximum compression (slowest, smallest file)
mediaproc image convert image.jpg -f png --compression 9 -o max_compressed.png

# Standard compression
mediaproc image convert photo.jpg -f png --compression 6 -o compressed.png

# Fast compression (larger file)
mediaproc image convert image.jpg -f png --compression 3 -o fast.png

# No compression (fastest, largest file)
mediaproc image convert photo.jpg -f png --compression 0 -o uncompressed.png

Progressive Formats

Create progressive/interlaced images:

# Progressive JPEG (loads gradually)
mediaproc image convert image.jpg -f jpg --progressive -o progressive.jpg

# Interlaced PNG
mediaproc image convert photo.png -f png --progressive -o interlaced.png

# Progressive JPEG with quality
mediaproc image convert large.jpg -f jpg --progressive -q 85 -o web_optimized.jpg

Web Optimization

Optimize images for web:

# Convert to WebP for modern browsers
mediaproc image convert photo.jpg -f webp -q 85 -o web.webp

# Convert to AVIF for maximum compression
mediaproc image convert image.png -f avif -q 80 -o ultra_compressed.avif

# Progressive JPEG for better UX
mediaproc image convert large_photo.jpg -f jpg --progressive -q 85 -o optimized.jpg

# WebP with high quality for hero images
mediaproc image convert hero.jpg -f webp -q 95 -o hero.webp

Batch Conversion

Convert multiple images:

# Convert all JPGs to WebP
for file in *.jpg; do
  mediaproc image convert "$file" -f webp -o "webp/${file%.jpg}.webp"
done

# Convert all PNGs to AVIF
for file in *.png; do
  mediaproc image convert "$file" -f avif -q 85 -o "avif/${file%.png}.avif"
done

# Convert all WebP to JPG (legacy support)
for file in *.webp; do
  mediaproc image convert "$file" -f jpg -q 90 -o "jpg/${file%.webp}.jpg"
done

# Convert photos to multiple formats
for photo in photos/*.jpg; do
  filename="${photo##*/}"
  basename="${filename%.jpg}"
  mediaproc image convert "$photo" -f webp -q 85 -o "output/${basename}.webp"
  mediaproc image convert "$photo" -f avif -q 80 -o "output/${basename}.avif"
done

Format Migration

Migrate entire image library:

# Migrate to WebP for web
find . -name "*.jpg" -o -name "*.png" | while read file; do
  dir="$(dirname "$file")"
  basename="$(basename "$file" | sed 's/\.[^.]*$//')"
  mediaproc image convert "$file" -f webp -q 85 -o "${dir}/${basename}.webp"
done

# Convert old formats to modern
for file in images/*.{jpg,png,gif}; do
  [ -f "$file" ] || continue
  mediaproc image convert "$file" -f avif -q 80 -o "modern/${file##*/}"
done

Combining Quality and Compression

Fine-tune output:

# High quality WebP
mediaproc image convert photo.jpg -f webp -q 95 -o high_webp.webp

# Balanced AVIF
mediaproc image convert image.png -f avif -q 85 -o balanced.avif

# Maximum PNG compression with quality
mediaproc image convert photo.jpg -f png --compression 9 -q 90 -o high_quality.png

# Progressive JPEG with custom quality
mediaproc image convert large.jpg -f jpg --progressive -q 85 -o progressive_optimized.jpg

Print Preparation

Prepare images for print:

# Convert to TIFF for professional print
mediaproc image convert photo.jpg -f tiff -q 100 -o print.tiff

# High-quality TIFF
mediaproc image convert image.png -f tiff -q 100 -o high_res_print.tiff

# Convert all photos for print
for file in photos/*.jpg; do
  mediaproc image convert "$file" -f tiff -q 100 -o "print_ready/${file##*/}"
done

Legacy Browser Support

Create fallback images:

# WebP with JPG fallback
mediaproc image convert photo.jpg -f webp -q 85 -o modern.webp
mediaproc image convert photo.jpg -f jpg -q 90 -o fallback.jpg

# Create both formats for <picture> element
for file in *.jpg; do
  basename="${file%.jpg}"
  mediaproc image convert "$file" -f webp -q 85 -o "webp/${basename}.webp"
  mediaproc image convert "$file" -f jpg -q 90 -o "jpg/${basename}.jpg"
done

Dry Run Testing

Test conversions before executing:

# Test WebP conversion
mediaproc image convert photo.jpg -f webp --dry-run

# Test AVIF with quality
mediaproc image convert image.png -f avif -q 80 --dry-run

# Test PNG compression
mediaproc image convert photo.jpg -f png --compression 9 --dry-run

# Test progressive JPEG
mediaproc image convert large.jpg -f jpg --progressive -q 85 --dry-run

Verbose Processing

Monitor conversion details:

# See format details
mediaproc image convert photo.jpg -f webp -v -o converted.webp

# Debug quality settings
mediaproc image convert image.png -f avif -q 80 -v -o compressed.avif

# Monitor batch conversion
for file in *.jpg; do
  mediaproc image convert "$file" -f webp -v -o "webp/${file##*/}"
done

Format Guide

WebP

Best for: Modern web, balanced quality/size

Advantages:

25-35% smaller than JPG/PNG
Supports transparency (like PNG)
Supports animation (like GIF)
Widely supported in modern browsers

Disadvantages:

Not supported in older browsers (IE, old Safari)
May show artifacts at very low quality

Recommended Quality: 80-90

Example:

mediaproc image convert photo.jpg -f webp -q 85 -o optimized.webp

AVIF

Best for: Maximum compression, next-gen web

Advantages:

40-50% smaller than JPG
Superior quality at same file size
Supports HDR and wide color gamut
Excellent detail preservation

Disadvantages:

Limited browser support (newer browsers only)
Slower encoding than WebP
Not all image tools support it

Recommended Quality: 75-85

Example:

mediaproc image convert image.png -f avif -q 80 -o ultra_compressed.avif

JPG/JPEG

Best for: Photos, legacy compatibility

Advantages:

Universal browser/device support
Good compression for photos
Fast encoding/decoding
Industry standard

Disadvantages:

Lossy compression (quality loss)
No transparency support
Larger than WebP/AVIF

Recommended Quality: 85-95 (photos), 90+ (high detail)

Example:

mediaproc image convert image.png -f jpg -q 90 --progressive -o photo.jpg

PNG

Best for: Graphics, transparency, lossless

Advantages:

Lossless compression
Supports full transparency
Good for graphics, text, screenshots
Universal support

Disadvantages:

Larger file sizes than JPG
Not ideal for photos
Slower encoding at high compression

Recommended Compression: 6-9

Example:

mediaproc image convert graphic.jpg -f png --compression 9 -o graphic.png

TIFF

Best for: Print, professional workflows

Advantages:

Lossless or lossy options
Industry standard for print
Supports layers, high bit depth
Excellent quality preservation

Disadvantages:

Very large file sizes
Not suitable for web
Overkill for most uses

Recommended Quality: 95-100

Example:

mediaproc image convert photo.jpg -f tiff -q 100 -o print_ready.tiff

GIF

Best for: Simple animations (use video formats for complex animations)

Advantages:

Universal support for animation
Simple format
Transparency support (1-bit)

Disadvantages:

Limited to 256 colors
Large file sizes for animations
Inferior to modern video formats
Not ideal for photos

Use Cases: Simple animations, legacy support

Example:

mediaproc image convert frame.png -f gif -o animation.gif

Quality Guidelines

Quality Values

95-100: Near lossless

Use for: Master files, archival, print
File size: Very large
Visual: No visible compression

85-95: High quality

Use for: Professional web, hero images
File size: Large to medium
Visual: Excellent, minimal artifacts

75-85: Good quality (recommended for most web)

Use for: Standard web images, galleries
File size: Medium
Visual: Good, minor artifacts on close inspection

65-75: Medium quality

Use for: Thumbnails, large quantity images
File size: Small
Visual: Noticeable artifacts under scrutiny

50-65: Low quality

Use for: Extreme compression needs, previews
File size: Very small
Visual: Visible artifacts, acceptable for previews

Format-Specific Recommendations

WebP:

Photos: quality 80-90
Graphics: quality 90-95
Thumbnails: quality 70-80

AVIF:

Photos: quality 75-85
Graphics: quality 85-90
Thumbnails: quality 65-75

JPG:

Photos: quality 85-95
Web: quality 80-90 with progressive
Thumbnails: quality 70-80

PNG:

Graphics/screenshots: compression 9
Photos: compression 6-9 (consider JPG instead)
Transparency: compression 9, quality 90+

Best Practices

Choose the Right Format:
- Photos → WebP or AVIF for web, JPG for legacy
- Graphics/logos → PNG or WebP
- Transparency needed → PNG or WebP
- Print → TIFF or high-quality JPG
Quality Selection:
- Start with quality 85 and adjust
- Use higher quality (90-95) for important images
- Use lower quality (70-80) for thumbnails
- Test visually to find acceptable quality level
Web Optimization Strategy:
- Primary: WebP or AVIF
- Fallback: JPG or PNG
- Use <picture> element for format support detection
- Serve format based on browser capabilities
Batch Processing:
- Convert similar images with same parameters
- Test on sample images first
- Preserve originals in separate folder
- Use consistent naming convention
Progressive Images:
- Use for images over 100KB
- Better perceived performance
- Especially important for hero images
- Works with JPG and PNG
Compression Levels:
- PNG: Use 9 for final outputs, 6 for faster processing
- Higher compression = smaller files but slower encoding
- Balance speed vs. file size based on needs

Common Use Cases

Website Image Optimization

# Convert all images for modern website
for img in images/*.{jpg,png}; do
  [ -f "$img" ] || continue
  basename="${img##*/}"
  name="${basename%.*}"

  # WebP for modern browsers
  mediaproc image convert "$img" -f webp -q 85 -o "optimized/${name}.webp"

  # AVIF for bleeding edge
  mediaproc image convert "$img" -f avif -q 80 -o "optimized/${name}.avif"

  # JPG fallback
  mediaproc image convert "$img" -f jpg -q 90 --progressive -o "optimized/${name}.jpg"
done

Photography Portfolio

# Convert RAW exports to multiple web formats
for photo in exports/*.jpg; do
  name="$(basename "$photo" .jpg)"

  # High-quality WebP for display
  mediaproc image convert "$photo" -f webp -q 90 -o "web/${name}.webp"

  # Progressive JPG fallback
  mediaproc image convert "$photo" -f jpg -q 88 --progressive -o "web/${name}.jpg"
done

E-commerce Product Images

# Product photos to optimized formats
for product in products/*.png; do
  name="$(basename "$product" .png)"

  # WebP for product display
  mediaproc image convert "$product" -f webp -q 90 -o "optimized/${name}.webp"

  # JPG fallback
  mediaproc image convert "$product" -f jpg -q 90 -o "optimized/${name}.jpg"
done

Blog Post Images

# Optimize blog images
for img in blog/*.jpg; do
  basename="${img##*/}"

  # WebP for modern browsers
  mediaproc image convert "$img" -f webp -q 85 -o "blog/webp/${basename%.jpg}.webp"

  # Progressive JPG
  mediaproc image convert "$img" -f jpg -q 85 --progressive -o "blog/optimized/${basename}"
done

Performance Tips

Encoding Speed: AVIF is slower than WebP, WebP slower than JPG
Batch Efficiency: Process similar images together with same parameters
Quality Trade-offs: Higher quality = larger files and slower encoding
Format Selection: Choose format based on content type (photos vs graphics)
PNG Compression: Level 9 much slower than 6; test if difference matters
Progressive: Minimal performance impact, significant UX benefit for large images

Troubleshooting

File Size Too Large

Problem: Converted file is larger than expected.

Solutions:

# Lower quality
mediaproc image convert image.jpg -f webp -q 75 -o smaller.webp

# Try different format
mediaproc image convert image.png -f avif -q 80 -o much_smaller.avif

# Use maximum PNG compression
mediaproc image convert image.jpg -f png --compression 9 -o compressed.png

# For JPG, use progressive
mediaproc image convert image.jpg -f jpg -q 80 --progressive -o optimized.jpg

Quality Loss Too Visible

Problem: Output shows too many compression artifacts.

Solutions:

# Increase quality
mediaproc image convert photo.jpg -f webp -q 95 -o high_quality.webp

# Try lossless PNG
mediaproc image convert image.jpg -f png --compression 9 -o lossless.png

# Use TIFF for no loss
mediaproc image convert photo.jpg -f tiff -q 100 -o no_loss.tiff

Browser Compatibility Issues

Problem: Format not supported in target browsers.

Solutions:

# Create JPG fallback
mediaproc image convert image.webp -f jpg -q 90 -o fallback.jpg

# Use universal format
mediaproc image convert modern.avif -f png -o compatible.png

# Create multiple formats for <picture> element
mediaproc image convert photo.jpg -f webp -o modern.webp
mediaproc image convert photo.jpg -f jpg --progressive -o fallback.jpg

Conversion Takes Too Long

Problem: Conversion is very slow.

Solutions:

# Use faster format (JPG instead of AVIF)
mediaproc image convert image.png -f jpg -q 90 -o faster.jpg

# Lower PNG compression
mediaproc image convert photo.jpg -f png --compression 6 -o faster_png.png

# Skip progressive for faster encoding
mediaproc image convert image.jpg -f jpg -q 85 -o no_progressive.jpg

# Process in parallel
ls *.jpg | parallel mediaproc image convert {} -f webp -o webp/{/.}.webp

Transparency Lost

Problem: Transparent areas become solid color.

Solutions:

# Use format that supports transparency (PNG or WebP)
mediaproc image convert image.png -f webp -o transparent.webp

# Keep as PNG
mediaproc image convert image.png -f png --compression 9 -o preserved.png

# Don't convert to JPG (doesn't support transparency)

Color Profile Issues

Problem: Colors look different after conversion.

Solutions:

# Use verbose mode to check profiles
mediaproc image convert image.jpg -f webp -v -o check_profile.webp

# Convert to sRGB first (use external tool)
# Then convert format

# Use higher quality to preserve color depth
mediaproc image convert image.jpg -f webp -q 95 -o color_accurate.webp