postprocess

Converts each pixel to luminance using the ITU-R BT.601 formula (0.299R + 0.587G + 0.114B) and writes the same value to R, G, and B. Alpha is preserved.

use plugin postprocess::{postprocess_grayscale}

// Assume `pixels` is an RGBA byte buffer from the image plugin
let grey = postprocess_grayscale(pixels, 640, 480)

Multiplies each RGB channel by factor. Values above 1.0 brighten; values below 1.0 darken. Result is clamped to 0–255. Alpha is preserved.

use plugin postprocess::{postprocess_brightness}

let brighter = postprocess_brightness(pixels, 800, 600, 1.4)
let darker = postprocess_brightness(pixels, 800, 600, 0.6)

Adjusts contrast by pivoting around mid-grey (0.5). factor above 1.0 increases contrast; below 1.0 reduces it. Alpha is preserved.

use plugin postprocess::{postprocess_contrast}

let high_contrast = postprocess_contrast(pixels, 640, 480, 2.0)

Inverts each RGB channel (255 minus the channel value). Produces a photo-negative effect. Alpha is preserved.

use plugin postprocess::{postprocess_invert}

let inverted = postprocess_invert(pixels, 320, 240)

Applies a warm sepia tone using standard sepia matrix coefficients. Gives images a classic antique photograph appearance.

use plugin postprocess::{postprocess_sepia}

let aged = postprocess_sepia(pixels, 640, 480)

Binarises each pixel: pixels with luminance >= value (0–255) become white (255), others become black (0). Alpha is preserved.

use plugin postprocess::{postprocess_threshold}

let binary = postprocess_threshold(pixels, 640, 480, 128.0)

Applies a box (mean) blur of the given pixel radius. Each pixel becomes the average of the square neighbourhood of side 2*radius+1. All four RGBA channels are blurred.

use plugin postprocess::{postprocess_box_blur}

let blurred = postprocess_box_blur(pixels, 800, 600, 3)

Darkens pixels toward the image edges based on their normalised distance from the centre. strength of 1.0 produces a moderate vignette; higher values produce stronger darkening.

use plugin postprocess::{postprocess_vignette}

let vignetted = postprocess_vignette(pixels, 1920, 1080, 1.5)

Extracts pixels brighter than threshold (luminance 0–255), blurs them with a small kernel, then adds the result back to the original image scaled by intensity. Simulates light scatter around bright sources.

use plugin postprocess::{postprocess_bloom}

let bloomed = postprocess_bloom(pixels, 1280, 720, 200.0, 0.8)

Applies Reinhard tone mapping: each channel c becomes c / (1 + c) (after normalising to 0.0–1.0 range). Compresses HDR values into displayable range smoothly.

use plugin postprocess::{postprocess_tone_map_reinhard}

let mapped = postprocess_tone_map_reinhard(hdr_pixels, 1920, 1080)

Applies the ACES filmic tone mapping approximation, which produces rich contrast and colour saturation that mimics film stock. Better suited to game rendering than Reinhard.

use plugin postprocess::{postprocess_tone_map_aces}

let mapped = postprocess_tone_map_aces(hdr_pixels, 1920, 1080)

Applies gamma correction (pow(channel, 1/gamma)) followed by saturation adjustment. saturation of 1.0 is unchanged; 0.0 is fully desaturated; values above 1.0 boost colours.

use plugin postprocess::{postprocess_color_grade}

// Warm, contrasty grade
let graded = postprocess_color_grade(pixels, 1280, 720, 2.2, 1.3)
// Desaturated grade
let grey = postprocess_color_grade(pixels, 1280, 720, 1.0, 0.0)

Sharpens the image using an unsharp-mask kernel where the centre weight is 1 + 4*strength and each cardinal neighbour is -strength. Higher strength produces more aggressive sharpening. Edge pixels are left unchanged.

use plugin postprocess::{postprocess_sharpen}

let sharp = postprocess_sharpen(pixels, 800, 600, 0.5)

Applies gamma correction to each RGB channel: out = pow(in/255, 1/gamma) * 255. Common values are 2.2 (display gamma) and 0.4545 (linear-to-sRGB).

use plugin postprocess::{postprocess_gamma}

let corrected = postprocess_gamma(pixels, 640, 480, 2.2)