92 lines
1.8 KiB
Go
92 lines
1.8 KiB
Go
package main
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import (
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"fmt"
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"image"
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_ "image/jpeg"
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"image/png"
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"math/rand"
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"os"
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"time"
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)
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func main() {
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if len(os.Args) == 1 || len(os.Args) > 4 || os.Args[1] == "help" {
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fmt.Printf(`usage: %s <path/to/image.ext> <dither_option> <path/to/output.png>
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Supported dither options are: noop, naive, randomnoise
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Supported input image formats are jpg, png
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`, os.Args[0])
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os.Exit(0)
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}
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filename := os.Args[1]
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ditherer := os.Args[2]
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outfile := os.Args[3]
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i, codex, err := loadImage(filename)
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if err != nil {
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fmt.Printf("error loading %s; %v\n", filename, err)
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os.Exit(255)
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}
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fmt.Printf("loaded %s using %s\n", filename, codex)
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t := time.Now()
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var new image.Image
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switch ditherer {
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case "noop":
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new = apply(i, noOp)
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case "naive":
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new = apply(i, naiveBW)
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case "randomnoise":
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rand.Seed(time.Now().UnixNano())
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new = apply(i, randomNoise)
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case "bayer0":
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new = apply(i, bayerDithering(0, false))
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case "bayer0n":
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new = apply(i, bayerDithering(0, true))
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case "bayer1":
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new = apply(i, bayerDithering(1, false))
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case "bayer1n":
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new = apply(i, bayerDithering(1, true))
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default:
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fmt.Printf("unknown ditherer option: %s\n", ditherer)
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os.Exit(2)
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}
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fmt.Printf("dithering took %s\n", time.Since(t))
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err = saveImage(outfile, new)
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if err != nil {
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fmt.Printf("error saving %s; %v\n", outfile, err)
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os.Exit(255)
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}
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fmt.Printf("saved output to %s\n", outfile)
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}
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func loadImage(filename string) (image.Image, string, error) {
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r, err := os.Open(filename)
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if err != nil {
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return nil, "", err
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}
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return image.Decode(r)
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}
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func saveImage(filename string, img image.Image) error {
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f, err := os.Create(filename)
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if err != nil {
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return err
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}
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if err := png.Encode(f, img); err != nil {
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f.Close()
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return err
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}
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if err := f.Close(); err != nil {
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return err
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}
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return nil
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}
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