C# .Net實現灰度圖和HeatMap熱力圖winform(進階)

一、前文

前文可以參考我的前一篇博文:C# .Net實現簡易灰度圖和酷炫HeatMap熱力圖winform

但是,先前的熱力圖效果,我並不滿意。不滿意的地方主要有三點:

  • 熱力圖的顏色是通過一個調色板圖片來實現,如果想要其他顏色,改起來比較麻煩
  • 熱力圖的擴散效果不好看,不夠漸進
  • 熱力圖的每個點大小都一致,應該是大小不一才對

因此,我做瞭改進,上一個圖是之前的效果,下一個圖是改進後的效果

二、漸進顏色調色板

//創建調色板,顏色映射
private ColorMap[] CreatePalette()
{
    ColorMap[] colorMaps = new ColorMap[256];
    List<Color> newColors = new List<Color>();

    //顏色集合
    newColors.AddRange(GetGradientColorList(Color.Red, Color.Yellow, 64));
    newColors.AddRange(GetGradientColorList(Color.Yellow, Color.Green, 64));
    newColors.AddRange(GetGradientColorList(Color.Green, Color.Blue, 64));
    newColors.AddRange(GetGradientColorList(Color.Blue, Color.Navy, 64));
    //顏色調色板展示
    Bitmap colorBitmap = new Bitmap(colorPanel.Width, colorPanel.Height);

    Graphics graphic = Graphics.FromImage(colorBitmap);             
    for (int i = 0; i < 256; i++)
    {
        SolidBrush solidBrush = new SolidBrush(newColors[i]);
        Rectangle rectangle = new Rectangle((int)(i * 2), 0, (int)2, colorPanel.Height);
        graphic.FillRectangle(solidBrush, rectangle);
        graphic.Save();
        solidBrush.Dispose();
    }
    colorPanel.BackgroundImage = colorBitmap;

    // 遍歷每個像素並創建一個新的顏色映射
    for (int X = 0; X <= 255; X++)
    {
        colorMaps[X] = new ColorMap();
        colorMaps[X].OldColor = System.Drawing.Color.FromArgb(X, X, X);
        colorMaps[X].NewColor = System.Drawing.Color.FromArgb(255, newColors[X]);
    }
    return colorMaps;
}

/// <summary>
/// 獲得兩個顏色之間漸進顏色的集合
/// </summary>
/// <param name="sourceColor">起始顏色</param>
/// <param name="destColor">終止顏色</param>
/// <param name="count">漸進顏色的個數</param>
/// <returns>返回顏色集合</returns>
public static List<Color> GetGradientColorList(Color srcColor, Color desColor, int count)
{
    List<Color> colorFactorList = new List<Color>();
    int redSpan = desColor.R - srcColor.R;
    int greenSpan = desColor.G - srcColor.G;
    int blueSpan = desColor.B - srcColor.B;
    for (int i = 0; i < count; i++)
    {
        Color color = Color.FromArgb(
            srcColor.R + (int)((double)i / count * redSpan),
            srcColor.G + (int)((double)i / count * greenSpan),
            srcColor.B + (int)((double)i / count * blueSpan)
        );
        colorFactorList.Add(color);
    }
    return colorFactorList;
}

三、熱力點大小和擴展大小

private void DrawHeatPoint2(Graphics graphics, HeatPoint heatPoint)
{
    Console.WriteLine("heatPoint.Intensity = " + heatPoint.Intensity);

    int radius = 40 * (heatPoint.Intensity+6) / 240;

    List<System.Drawing.Point> pointsList = new List<System.Drawing.Point>();
    for (double degrees = 0; degrees <= 360; degrees += 10)
    {
        // 在定義半徑的圓的圓周上繪制新點
        // 使用點坐標、半徑和角度
        // 計算這個迭代點在圓上的位置
        System.Drawing.Point point = new System.Drawing.Point();
        point.X = Convert.ToInt32(heatPoint.X + radius * Math.Cos((Math.PI / 180) * degrees));
        point.Y = Convert.ToInt32(heatPoint.Y + radius * Math.Sin((Math.PI / 180) * degrees));
        pointsList.Add(point);
    }

    // 創建新的顏色混合來告訴 PathGradientBrush 使用什麼顏色以及放置它們的位置
    ColorBlend colorBlend = new ColorBlend(3);

    colorBlend.Positions = new float[3] { 0, 0.8f, 1 };
    colorBlend.Colors = new System.Drawing.Color[3]
    {
        System.Drawing.Color.FromArgb(0, System.Drawing.Color.White),
        System.Drawing.Color.FromArgb(heatPoint.Intensity, System.Drawing.Color.Black),
        System.Drawing.Color.FromArgb(heatPoint.Intensity, System.Drawing.Color.Black)
    };

    // 創建新的 PathGradientBrush 以使用圓周點創建徑向漸變
    PathGradientBrush brush = new PathGradientBrush(pointsList.ToArray());
    // 將顏色混合傳遞給 PathGradientBrush 以指示它如何生成漸變
    brush.InterpolationColors = colorBlend;
    graphics.FillPolygon(brush, pointsList.ToArray());
    //brush.Dispose();
}

四、更新視圖 

private void UpdateView()
{
    //灰度
    Bitmap bitmap1 = CreateIntensityMask(new Bitmap((int)panel1.Width, (int)panel1.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb), heatPoints, 1);
    panel1.BackgroundImage = bitmap1;

    //上色
    panel3.BackgroundImage = Colorize(bitmap1);
}


private Bitmap CreateIntensityMask(Bitmap bitmap, List<HeatPoint> aHeatPoints)
{
    //從Bitmap獲得Graphics GDI+ 繪圖圖面
    Graphics graphics = Graphics.FromImage(bitmap);
    //清除整個繪圖面並以白色填充
    graphics.Clear(System.Drawing.Color.White);
    foreach (HeatPoint point in aHeatPoints)
    {
       DrawHeatPoint2(graphics, point);
    }
    return bitmap;
} 

到此這篇關於C# .Net實現灰度圖和HeatMap熱力圖winform(進階)的文章就介紹到這瞭,更多相關C# .Net 灰度圖 熱力圖內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet!

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