关于渐变色的研究

近在研究灰度图像的渲染。arcgis在对dem进行渲染的时候出来的图也很精美。这得意于它色卡，色卡都是渐变色。因此出来的图具有渐变效果，栅格颜色之间的过渡很自然。

      1为效果图,2为色卡。

经过我的研究其实这里的色卡得到的过程如下：

Blue渐变到（0，255，255），（0，255，255）渐变到Yellow，Yellow渐变到Red

 

 

1 效果图。

 

2 色卡

 

int stepnum = 1200;
            Color[] color1 = new Color[2];
            color1[0] = Color.Blue;
            color1[1] = Color.FromArgb(0, 255, 255);
            Color[] clr1 = this.GetGradient(color1, 400);

            Color[] color2 = new Color[2];
            color2[0] = Color.FromArgb(0, 255, 255);
            color2[1] = Color.Yellow;
            Color[] clr2 = this.GetGradient(color2, 400);

            Color[] color3 = new Color[2];
            color3[0] = Color.Yellow;
            color3[1] = Color.FromArgb(255, 0, 0);
            Color[] clr3 = this.GetGradient(color3, 400);

            int len = clr1.Length + clr2.Length + clr3.Length;
            Color[] color = new Color[len];
            for (int i = 0; i < clr1.Length; i++)
            {
                color[i] = clr1[i];
            }
            for (int i = clr1.Length; i < clr1.Length + clr2.Length; i++)
            {
                color[i] = clr2[i - clr1.Length];
            }
            for (int i = clr1.Length + clr2.Length; i < clr1.Length + clr2.Length + clr3.Length; i++)
            {
                color[i] = clr3[i - clr1.Length - clr2.Length];
            }

            //下面创建bitmap开始画图
            Bitmap bm = new Bitmap(stepnum, stepnum);
            for (int i = 0; i < stepnum; i++)
            {
              

                for (int j = 0; j < 50; j++)
                {
                    //通过设置每个像素点的值画图
                    bm.SetPixel(i, j,color[i]);
                }

           
            }
            //在窗体上显示,预览
            Graphics g = this.CreateGraphics();
            g.DrawImage(bm, 0, 100);