Modifiers Reference

Options

Option	Description
`-o <file>`	Output filename
`-d <dir>`	Output directory
`-v`	Verbose output
`--preset <file>`	Load modifier chain from preset file
`--help`	Show help message

Color Adjustments (21 modifiers)

Modifier	Usage	Description
`brightness`	`brightness <value>`	Adjust brightness (-128 to 127)
`contrast`	`contrast <factor>`	Adjust contrast
`saturation`	`saturation <factor>`	Adjust color saturation
`gamma`	`gamma <value>`	Apply gamma correction
`vibrance`	`vibrance <factor>`	Adjust vibrance (smart saturation)
`exposure`	`exposure <value>`	Adjust exposure (-2.0 to 2.0)
`hue-shift`	`hue-shift <degrees>`	Shift hue (-180 to 180)
`adjust-hsl`	`adjust-hsl <hue> <sat> <light>`	Adjust hue, saturation, and lightness separately
`adjust-channels`	`adjust-channels <red> <green> <blue>`	Adjust RGB channel intensities
`colorize`	`colorize <#RRGGBB> <intensity>`	Tint image with hex color
`duotone`	`duotone <#dark> <#light>`	Apply duotone effect (Spotify-style) using hex colors
`posterize`	`posterize <levels>`	Reduce color levels (2-256)
`threshold`	`threshold <value>`	Convert to black/white based on luminance (0-255)
`solarize`	`solarize <threshold>`	Invert colors above threshold (0-255)
`equalize`	`equalize`	Apply histogram equalization for better contrast
`equalize-area`	`equalize-area <x> <y> <width> <height>`	Apply histogram equalization to specific region
`grayscale`	`grayscale`	Convert to grayscale
`sepia`	`sepia`	Apply sepia tone
`invert`	`invert`	Invert colors

Filters (15 modifiers)

Modifier	Usage	Description
`blur`	`blur <size>`	Box blur (kernel size, odd numbers)
`gaussian-blur`	`gaussian-blur <sigma>`	Gaussian blur with configurable sigma
`sharpen`	`sharpen`	Sharpen image
`emboss`	`emboss <strength>`	Emboss effect for 3D-like appearance
`color-emboss`	`color-emboss <strength>`	Emboss effect with color preservation
`edge-detect`	`edge-detect`	Detect edges using Sobel operator
`edge-enhancement`	`edge-enhancement <strength>`	Enhance edges (0.0-2.0)
`median-filter`	`median-filter <size>`	Median filter for noise reduction (odd kernel size)
`denoise`	`denoise <strength>`	Remove noise using bilateral filter (1-10)
`pixelate`	`pixelate <size>`	Apply pixelation/mosaic effect
`oil-painting`	`oil-painting <radius>`	Apply oil painting artistic effect
`vignette`	`vignette <intensity>`	Apply vignette effect to darken corners (0.0-1.0)
`glow`	`glow <intensity> <radius>`	Add soft glow around bright areas
`tilt-shift`	`tilt-shift <blur> <focus_pos> <focus_width>`	Advanced tilt-shift effect with two-pass Gaussian blur, smooth focus transitions, and subtle saturation boost for realistic miniature appearance. Blur: 0.0-10.0, Focus position: 0.0-1.0 (top to bottom), Focus width: 0.0-1.0
`noise`	`noise <amount>`	Add random noise to image (0.0-1.0)
`gradient-linear`	`gradient-linear <start_color> <end_color> <angle> <opacity>`	Apply linear gradient overlay
`gradient-radial`	`gradient-radial <cx> <cy> <start_color> <end_color> <radius> <opacity>`	Apply radial gradient overlay
`censor`	`censor <x> <y> <width> <height> <method> <strength>`	Apply censoring effect (blur/pixelate/black)

Transforms (6 modifiers)

Modifier	Usage	Description
`resize`	`resize <width> <height>`	Resize image using nearest-neighbor sampling
`crop`	`crop <x> <y> <width> <height>`	Crop image using top-left coordinate and size
`rotate`	`rotate <degrees>`	Rotate image clockwise by any angle (auto-resizes canvas)
`flip`	`flip <horizontal\|vertical>`	Flip image horizontally or vertically
`round-corners`	`round-corners <radius>`	Round corners with specified radius

Usage Examples

# Single modifier
zig build run -- input.png brightness 20 -o output.png

# Chain multiple modifiers
zig build run -- input.png brightness 10 contrast 1.2 sharpen -o output.png

# Advanced color grading
zig build run -- photo.jpg vibrance 0.3 exposure 0.2 contrast 1.1 hue-shift 15 -o graded.png

# Artistic effects
zig build run -- photo.jpg oil-painting 3 posterize 8 vignette 0.4 -o artistic.png

# Professional portrait enhancement
zig build run -- portrait.jpg median-filter 3 vibrance 0.2 contrast 1.1 sharpen -o enhanced.png

# Batch processing
zig build run -- *.jpg grayscale posterize 6 -d output/

# Creative duotone effect
zig build run -- photo.jpg duotone #333333 #C8C8C8 contrast 1.2 -o duotone.png

# Edge detection for comic effect
zig build run -- photo.jpg edge-detect posterize 6 contrast 1.5 -o comic.png

Supported Formats

Input: PNG, TGA, QOI, PAM, PBM, PGM, PPM, PCX
Output: PNG, TGA, QOI, PAM, PBM, PGM, PPM, PCX