无法在位图中设置调色板

问题描述

我一直在编写 PCX 解码器，到目前为止，PCX 图像本身解析得很好，但我不知道如何设置位图的调色板.

I have been writing a PCX decoder and, so far, the PCX image itself parses fine, but I can't work out how to set the palette of a bitmap.

我已经创建了一个像这样的位图:

I have created a bitmap like so:

Bitmap bmp = new Bitmap(width,
                        height,
                        stride2,
                        System.Drawing.Imaging.PixelFormat.Format8bppIndexed,
                        pixels);

但我似乎无法使用以下方法设置调色板:

But I can't seem to set the palette using the following method:

for (int i = 0; i < 256; i += 3)
{
    Color b = new Color();
    b = Color.FromArgb(palette[i], palette[i + 1], palette[i + 2]);
    bmp.Palette.Entries.SetValue(b, i);
}

在这个例子中，我已经阅读了 pcx 文件调色板中的每个字节并将它们存储在调色板 [] 中.从那里，我用它来设置位图调色板中的条目.如何设置颜色?

In this example, I have read through each byte in the palette of the pcx file and stored them in palette[]. from there, I have used this to set the entries in the palette of the bitmap. How do I set the colours?

推荐答案

这也让我感到困惑.似乎 bitmap.Palette 返回位图调色板的克隆.一旦你修改了你的副本，你需要使用 bitmap.Palette = Palette 重置位图的调色板，例如

This had me confused too. It seems bitmap.Palette returns a clone of the bitmap's palette. Once you've modified your copy, you need to reset the bitmap's pallete by using bitmap.Palette = palette, e.g.

ColorPalette palette = bitmap.Palette;
Color entries = palette.Entries;
....
entries[i] = new Color(...);
....
bitmap.Palette = palette; // The crucial statement

参见 http://www.charlespetzold.com/pwcs/PaletteChange.html