just_image_cli

Command-line tool for high-performance image processing, powered by just_image.

Resize, convert, crop, rotate, apply artistic filters, generate thumbnails, and work with BlurHash — all from the terminal.

Prerequisites

• Dart SDK >= 3.10.8
• Rust toolchain (rustup.rs)

Installation

dart pub global activate just_image_cli

Commands

process — Transform images

just_image_cli process -i photo.jpg -o result.webp [options]

Option	Description	Example
-i, --input	Input file path (required)	-i photo.jpg
-o, --output	Output file path (required)	-o out.webp
--resize	Resize to WxH	--resize 1920x1080
-f, --format	Output format (jpeg, png, webp, avif, tiff, bmp)	-f webp
-q, --quality	Compression quality 1-100 (default: 90)	-q 85
--blur	Gaussian blur sigma	--blur 2.0
--sharpen	Sharpen amount	--sharpen 1.5
--brightness	Brightness -1.0, 1.0	--brightness 0.1
--contrast	Contrast -1.0, 1.0	--contrast 0.2
--rotate	Rotation in degrees	--rotate 90
--flip	Flip direction (horizontal, vertical)	--flip horizontal
--crop	Crop as X,Y,W,H	--crop 0,0,800,600
--filter	Apply artistic filter by name	--filter vintage
--thumbnail	Generate thumbnail WxH	--thumbnail 200x200
--watermark	Watermark image path	--watermark logo.png
--watermark-x	Watermark X offset (default: 0)	--watermark-x 50
--watermark-y	Watermark Y offset (default: 0)	--watermark-y 50
--watermark-opacity	Watermark opacity 0.0-1.0 (default: 1.0)	--watermark-opacity 0.7

filters — List available filters

just_image_cli filters

Output:

Available filters (15):
  • vintage
  • sepia
  • cool
  • warm
  • marine
  • dramatic
  • lomo
  • retro
  • noir
  • bloom
  • polaroid
  • golden_hour
  • arctic
  • cinematic
  • fade

blurhash — Encode/decode BlurHash

# Encode an image to BlurHash string
just_image_cli blurhash encode -i photo.jpg

# Decode a BlurHash string to PNG
just_image_cli blurhash decode --hash "LEHV6nWB2yk8..." -o placeholder.png --width 32 --height 32

info — Inspect images

just_image_cli info -i photo.jpg

Output:

File:       photo.jpg
Dimensions: 4032x3024
File size:  3.2 MB

Examples

# Apply vintage filter and convert to WebP
just_image_cli process -i photo.jpg -o vintage.webp --filter vintage -f webp -q 85

# Generate thumbnail
just_image_cli process -i photo.jpg -o thumb.jpg --thumbnail 200x200

# Encode BlurHash for a placeholder
just_image_cli blurhash encode -i photo.jpg
# Output: LEHV6nWB2yk8pyo0adR*.7kCMdnj

# Full pipeline: resize, filter, and format conversion
just_image_cli process -i raw.tiff -o final.avif \
  --resize 1920x1080 --filter cinematic --brightness 0.05 -f avif -q 80

# Add watermark with transparency
just_image_cli process -i photo.jpg -o branded.jpg \
  --watermark logo.png --watermark-x 50 --watermark-y 50 --watermark-opacity 0.5

License

See LICENSE.