Go Glitch

A go package to glitch an image based on an expression you pass in as input! The only limit is your creativity (and patience)!

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What is the deal with the expressions?

You can think of the image as a functor that you map an expression to, for each pixel's component colors, returning a new one. The allowed operators are:

• + plus
• - minus
• * multiplication
• / division
• % modulo
• # power of operator
• & bit and
• | bit or
• : bit and not
• ^ bit xor
• < bit left shift
• > bit right shift
• ? returns 255 if left side is greater otherwise 0
• @ attributes a weight in the range [0, 255] to the value on the left

The expressions are made up of operators, numbers, parenthesis, and a set of parameters:

• c the current value of each pixel component color
• b the blurred version of c
• h the horizontally flipped version of c
• v the vertically flipped version of c
• d the diagonally flipped version of c
• Y the luminosity, or grayscale component of each pixel
• N a noise pixel (i.e. a pixel where each component is a random value)
• R the red color (i.e. rgb(255, 0, 0))
• G the green color (i.e. rgb(0, 255, 0))
• B the blue color (i.e. rgb(0, 0, 255))
• s the value of each pixel's last saved evaluated expression
• r a pixel made up of a random color component from the neighboring 8 pixels
• e the difference of all pixels in a box, creating an edge-like effect
• x the current x coordinate being evaluated normalized in the range [0, 255]
• y the current y coordinate being evaluated normalized in the range [0, 255]
• H the highest valued color component in the neighboring 8 pixels
• L the lowest valued color component in the neighboring 8 pixels

Examples

• 128 & (c - ((c - 150 + s) > 5 < s))
• (c & (c ^ 55)) + 25
• 128 & (c + 255) : (s ^ (c ^ 255)) + 25

More examples can be found here.

Command line tool usage

Use the docker image:

$ docker run sugoiuguu/go-glitch

API usage

package main

import (
    "os"
    "time"
    "math/rand"
    "image"
    "image/png"
    _ "image/jpeg"

    "github.com/sugoiuguu/go-glitch"
)

func main() {
    f, err := os.Open(os.Args[2])
    if err != nil {
        panic(err)
    }
    defer f.Close()

    f2, err := os.Create(os.Args[1])
    if err != nil {
        panic(err)
    }
    defer f2.Close()

    img, _, err := image.Decode(f)
    if err != nil {
        panic(err)
    }

    rand.Seed(time.Now().UnixNano())

    expr, err := glitch.CompileExpression("(n|(c > 1)) ^ 128")
    if err != nil {
        panic(err)
    }

    g, err := expr.JumblePixels(img)
    if err != nil {
        panic(err)
    }
    png.Encode(f2, g)
}

C/C++ interface

There is an experimental interface for C/C++ code here. The API is:

typedef struct {
    char *data;
    size_t size;
} Image_t;

extern Image_t *jumble_pixels(char *expression, char *data, int size);