从golang图像获取像素数组 [英] Get a pixel array from from golang image.Image

问题描述

我需要以 [] byte 的形式获取像素数组，以将其传递给texImage2D 方法/mobile/中的.org/golang.org/x/mobile/gl#Context> Contex gl 包.

I need to get a pixel array in the form of []byte to be passed to the texImage2D method of a Contex from the /mobile/gl package.

它需要一个像素阵列，其中每个像素的rgba值按从左到右，从上到下的像素顺序附加.目前，我已从文件加载图像.

It needs a pixel array where rgba values of each pixel is appended in the order of pixels left to right, top to bottom. Currently I have an image loaded from a file.

a, err := asset.Open("key.jpeg")
if err != nil {
    log.Fatal(err)
}
defer a.Close()

img, _, err := image.Decode(a)
if err != nil {
    log.Fatal(err)
}

我正在寻找类似 img.Pixels()

推荐答案

您可以简单地使用 img.At(x，y).RGBA()来获取像素的RBGA值，只需将它们除以257就可以得到8位的表示形式.我建议您建立自己的二维像素阵列.这是一个可能的实现，请根据需要对其进行修改:

You can simply use img.At(x, y).RGBA() to get the RBGA values for a pixel, you just need to divide them by 257 to get the 8 bit representation. I'd recommend building your own bi-dimensional array of pixels. Here's a possible implementation, modify it as needed:

package main

import (
    "fmt"
    "image"
    "image/png"
    "os"
    "io"
    "net/http"
)

func main() {
    // You can register another format here
    image.RegisterFormat("png", "png", png.Decode, png.DecodeConfig)

    file, err := os.Open("./image.png")

    if err != nil {
        fmt.Println("Error: File could not be opened")
        os.Exit(1)
    }

    defer file.Close()

    pixels, err := getPixels(file)

    if err != nil {
        fmt.Println("Error: Image could not be decoded")
        os.Exit(1)
    }

    fmt.Println(pixels)
}

// Get the bi-dimensional pixel array
func getPixels(file io.Reader) ([][]Pixel, error) {
    img, _, err := image.Decode(file)

    if err != nil {
        return nil, err
    }

    bounds := img.Bounds()
    width, height := bounds.Max.X, bounds.Max.Y

    var pixels [][]Pixel
    for y := 0; y < height; y++ {
        var row []Pixel
        for x := 0; x < width; x++ {
            row = append(row, rgbaToPixel(img.At(x, y).RGBA()))
        }
        pixels = append(pixels, row)
    }

    return pixels, nil
}

// img.At(x, y).RGBA() returns four uint32 values; we want a Pixel
func rgbaToPixel(r uint32, g uint32, b uint32, a uint32) Pixel {
    return Pixel{int(r / 257), int(g / 257), int(b / 257), int(a / 257)}
}

// Pixel struct example
type Pixel struct {
    R int
    G int
    B int
    A int
}

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