将图像的像素设置为整数数组中存储的值

Question

namespace txtToImg
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            string fileContent = File.ReadAllText("D:\\pixels.txt");

            string[] integerStrings = fileContent.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

            int[] integers = new int[integerStrings.Length];

            for (int n = 0; n < integerStrings.Length; n++)
            {
                integers[n] = int.Parse(integerStrings[n]);
            }

            Bitmap my = new Bitmap(512, 512);

            for (int i = 0; i < 512; i++)
                for (int j = 0; j < 512; j++)
                    my.SetPixel(i, j, Color.Blue);
            my.Save("D:\\my.jpg");

        }
    }
}

我想使用数组中的值，而不是像我所做的那样将所有像素设置为蓝色。

这就是我将像素保存到文本文件的方式！它们是从 0 到 255 的整数。现在我正在尝试处理灰度图像，所以我不需要单独的 R、G 和 B，这就是 (R+G+B)/3 的原因。

using (Bitmap bitmap = new Bitmap("D:\\6.jpg"))
    {
        int width = 512;
        int height = 512;
        TextWriter tw = new StreamWriter("D:\\pixels.txt");

        for (int i = 0; i < height; i++)
        {
            for (int j = 0; j < width; j++)
            {
                Color color = bitmap.GetPixel(j, i);
                tw.Write((color.R + color.G + color.B) / 3 + " ");
            }
            //tw.Write(" ");
        }
        tw.Close();
    }

Answer 1

由于您已经拥有每种颜色 1 个字节的灰度值，因此对新图像使用 Format8bppIndexed 是有意义的：

// Create 8 bit per pixel bitmap
var bitmap = new Bitmap(512, 512, PixelFormat.Format8bppIndexed);

// Set grayscale color palette
var colorPalette = bitmap.Palette;
var colorEntries = colorPalette.Entries;

for ( int i = 0; i < 256; i++ )
{
    colorEntries[i] = Color.FromArgb(i, i, i);
}

// Apply changes to color pallete
bitmap.Palette = colorPalette;

// Retrieve bitmap data for efficient writes
var bitmapData = bitmap.LockBits(Rectangle.FromLTRB(0, 0, 512, 512), ImageLockMode.WriteOnly, PixelFormat.Format8bppIndexed);

// Allocate array to store intermediate pixel data
byte[] colorData = new byte[bitmapData.Stride * bitmapData.Height]; // 1 byte per pixel since it is 8bppIndexed format

for (int i = 0; integers.Length; i++)
{
    int line = i / 512;
    int position = i % 512;

    colorData[line * bitmapData.Stride + position] = (byte)integers[i]; // color values from file
}

// Copy computed pixel data to BitmapData
Marshal.Copy(colorData, 0, bitmapData.Scan0, colorData.Length);

bitmap.UnlockBits(bitmapData);

bitmap.Save("D:\\test.bmp");