Golangを使用して画像を白黒およびハーフトーン効果に変換する方法

package main

import (
    "image"
    "image/color"
    "image/jpeg"
    "log"
    "os"
)

func loadImage(filename string) (image.Image, error) {
    file, err := os.Open(filename)
    if err != nil {
        return nil, err
    }
    defer file.Close()

    img, err := jpeg.Decode(file)
    if err != nil {
        return nil, err
    }

    return img, nil
}

func toGrayscale(img image.Image) *image.Gray {
    bounds := img.Bounds()
    gray := image.NewGray(bounds)

    for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
        for x := bounds.Min.X; x < bounds.Max.X; x++ {
            oldColor := img.At(x, y)
            grayColor := color.GrayModel.Convert(oldColor)
            gray.Set(x, y, grayColor)
        }
    }

    return gray
}

func toHalftone(img image.Image) *image.Gray16 {
    bounds := img.Bounds()
    halftone := image.NewGray16(bounds)

    for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
        for x := bounds.Min.X; x < bounds.Max.X; x++ {
            oldColor := img.At(x, y)
            halftoneColor := color.Gray16Model.Convert(oldColor)
            halftone.Set(x, y, halftoneColor)
        }
    }

    return halftone
}

func saveImage(img image.Image, filename string) error {
    file, err := os.Create(filename)
    if err != nil {
        return err
    }
    defer file.Close()

    err = jpeg.Encode(file, img, nil)
    if err != nil {
        return err
    }

    return nil
}

func main() {
    // 读取图片文件
    img, err := loadImage("input.jpg")
    if err != nil {
        log.Fatal(err)
    }

    // 转换为黑白效果
    gray := toGrayscale(img)
    err = saveImage(gray, "output_gray.jpg")
    if err != nil {
        log.Fatal(err)
    }

    // 转换为半色调效果
    halftone := toHalftone(img)
    err = saveImage(halftone, "output_halftone.jpg")
    if err != nil {
        log.Fatal(err)
    }

    log.Println("图片转换完成")
}