C#无插值调整图像大小

时间:2015-11-11 15:21:02

标签: c# graphics paint interpolation antialiasing

我知道这个问题经常被问到,但没有一个典型的答案给了我需要的结果。我试图像Paint.exe一样缩放灰度位图。我不需要插值,因此可以观察到原始的单个像素。我已经尝试了经常建议的NearestNeighbor方法,它接近但不完全是我想要的。

这就是我想要的:

Here is what I need

这就是我得到的:

Here is what I get with my application

这是我用来缩放和重绘图像的代码。

protected override void OnPaint(PaintEventArgs e)
{
    e.Graphics.PixelOffsetMode = PixelOffsetMode.Half;
    e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;            
    e.Graphics.SmoothingMode = SmoothingMode.None;

    Matrix m = new Matrix();
    m.Scale(mScale, mScale, MatrixOrder.Append);
    e.Graphics.Transform = m;

    e.Graphics.TranslateTransform(this.AutoScrollPosition.X / mScale,this.AutoScrollPosition.Y / mScale);

    if (mImage != null) 
        e.Graphics.DrawImage(mImage, 0, 0);

    base.OnPaint(e);
}

当缩放工作时,代码会对图像产生影响,更改InterpolationMode会改变图像。但是,没有任何设置组合可以获得我需要的结果。

有什么想法吗?

1 个答案:

答案 0 :(得分:0)

我正在尝试使用C#显示16位图像。我遇到了同样的麻烦,即完全相同的像素中的颜色不相同。最后,我用下面的示例代码解决了这个问题:

        protected override void OnPaint(PaintEventArgs e)
        {
            e.Graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
            e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor; 
            e.Graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighSpeed;
            e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.None;

            e.Graphics.Clear(Color.Black); //Clear the background with the black color

            if(m_bmp != null)  //if m_bmp == null, then do nothing.
            {
                //To calculate the proper display area's width and height that fit the window.
                if (this.Width / (double)this.Height > m_bmp.Width / (double)m_bmp.Height)
                {
                    m_draw_height = (int)(this.Height * m_roomRatio);
                    m_draw_width = (int)(m_bmp.Width / (double)m_bmp.Height * m_draw_height);
                }
                else
                {
                    m_draw_width = (int)(this.Width * m_roomRatio);
                    m_draw_height = (int)(m_bmp.Height / (double)m_bmp.Width * m_draw_width);
                }

                //To calculate the starting point.
                m_draw_x = (int)((this.Width - m_draw_width) / 2.0 + m_offsetX / 2.0);
                m_draw_y = (int)((this.Height - m_draw_height) / 2.0 + m_offsetY / 2.0);
                e.Graphics.DrawImage(m_bmp, m_draw_x, m_draw_y, m_draw_width, m_draw_height);

                //draw some useful information
                string window_info = "m_draw_x" + m_draw_x.ToString() + "m_draw_width" + m_draw_width.ToString();
                e.Graphics.DrawString(window_info, this.Font, new SolidBrush(Color.Yellow), 0, 20);
            }

顺便说一句,为什么不尝试使用双缓冲区来提高绘图图像的性能?

效果如下: enter image description here
希望会有所帮助。