Golang の画像操作: 画像のグレースケールと明るさの調整方法

go get -u github.com/lazywei/go-opencv

package main

import (
    "fmt"
    "github.com/lazywei/go-opencv/opencv"
)

func main() {
    imagePath := "test.jpg"
    // 通过go-opencv的LoadImage方法读取图片
    image := opencv.LoadImage(imagePath)
    defer image.Release()

    // 使用go-opencv的CvtColor方法将图片转为灰度图像
    grayImage := opencv.CreateImage(image.Width(), image.Height(), 8, 1)
    opencv.CvtColor(image, grayImage, opencv.CV_BGR2GRAY)

    // 保存灰度图像
    outputPath := "output_gray.jpg"
    opencv.SaveImage(outputPath, grayImage, 0)
    fmt.Printf("Gray image saved to: %s
", outputPath)
}

go get -u github.com/nfnt/resize

package main

import (
    "fmt"
    "image"
    "image/color"
    "github.com/nfnt/resize"
)

func main() {
    imagePath := "test.jpg"
    // 使用Golang内置的image包加载图片
    img, err := loadImage(imagePath)
    if err != nil {
        fmt.Printf("Failed to load image: %s
", err)
        return
    }

    // 调整图片亮度
    brightness := 50
    brightImage := adjustBrightness(img, brightness)

    // 保存亮度调整后的图片
    outputPath := "output_bright.jpg"
    saveImage(outputPath, brightImage)
    fmt.Printf("Brightness adjusted image saved to: %s
", outputPath)
}

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

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

    return img, nil
}

// 调整图片亮度
func adjustBrightness(img image.Image, brightness int) image.Image {
    b := img.Bounds()
    dst := image.NewRGBA(b)

    for y := 0; y < b.Max.Y; y++ {
        for x := 0; x < b.Max.X; x++ {
            oldColor := img.At(x, y)
            r, g, b, _ := oldColor.RGBA()

            newR := uint8(clamp(int(r)+brightness, 0, 0xffff))
            newG := uint8(clamp(int(g)+brightness, 0, 0xffff))
            newB := uint8(clamp(int(b)+brightness, 0, 0xffff))

            newColor := color.RGBA{newR, newG, newB, 0xff}
            dst.Set(x, y, newColor)
        }
    }

    return dst
}

// 保存图片
func saveImage(path string, img image.Image) {
    file, err := os.Create(path)
    if err != nil {
        fmt.Printf("Failed to save image: %s
", err)
        return
    }
    defer file.Close()

    png.Encode(file, img)
}

// 辅助函数，限定数值在指定范围内
func clamp(value, min, max int) int {
    if value < min {
        return min
    }
    if value > max {
        return max
    }
    return value
}