索引图像上的图形

Question

我收到错误:

"无法从具有索引像素格式的图像创建图形对象."

在功能:

public static void AdjustImage(ImageAttributes imageAttributes, Image image)
{
        Rectangle rect = new Rectangle(0, 0, image.Width, image.Height);

        Graphics g = Graphics.FromImage(image);       
        g.InterpolationMode = InterpolationMode.HighQualityBicubic;
        g.DrawImage(image, rect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, imageAttributes);
        g.Dispose();
}

我想问你,我该如何解决？

Answer 1

参考这个,它可以通过创建一个具有相同尺寸的空白位图和正确的PixelFormat以及该位图上的绘图来解决.

// The original bitmap with the wrong pixel format. 
// You can check the pixel format with originalBmp.PixelFormat
Bitmap originalBmp = new (Bitmap)Image.FromFile("YourFileName.gif");

// Create a blank bitmap with the same dimensions
Bitmap tempBitmap = new Bitmap(originalBmp.Width, originalBmp.Height);

// From this bitmap, the graphics can be obtained, because it has the right PixelFormat
using(Graphics g = Graphics.FromImage(tempBitmap))
{
    // Draw the original bitmap onto the graphics of the new bitmap
    g.DrawImage(originalBmp, 0, 0);
    // Use g to do whatever you like
    g.DrawLine(...);
}

// Use tempBitmap as you would have used originalBmp
return tempBitmap;

Answer 2

最简单的方法是创建一个新图像，如下所示：

Bitmap EditableImg = new Bitmap(IndexedImg);

它会创建一个与原始图像完全相同的新图像。