了解使用 ColorMatrix 和 ColorMatrixColorFilter 修改 Drawable 的色调

Question

我正在为一个应用程序开发用户界面，我正在尝试使用灰度图标，并允许用户将主题更改为他们选择的颜色。为此，我尝试仅应用某种 ColorFilter 将颜色覆盖在可绘制对象的顶部。我尝试过使用 PorterDuff.Mode.MULTIPLY，它的工作原理几乎完全符合我的需要，只是白色也被颜色覆盖。我理想中寻找的是类似 Photoshop 中的“颜色”混合模式，其中图形保留其透明度和亮度，并且仅修改图像的颜色。例如：

变为

经过一些研究，似乎 ColorMatrixColorFilter 类可以满足我的需要，但我似乎找不到任何指向如何使用矩阵的资源。这是一个 4x5 矩阵，但我需要知道的是如何设计该矩阵。有什么想法吗？

编辑：好吧，到目前为止我发现的内容如下：

1 0 0 0 0 //red
0 1 0 0 0 //green
0 0 1 0 0 //blue
0 0 0 1 0 //alpha

这个矩阵是单位矩阵（应用时，不进行任何更改），数字范围从 0 到 1（浮点数）。该矩阵将与每个像素相乘以转换为新颜色。所以这就是我开始变得模糊的地方。所以我认为每个像素都是一个 1 x 4 向量，其中包含 argb 值（例如 0.2, 0.5, 0.8, 1），该值将用变换矩阵点缀。因此，要将图像的红色强度加倍，您可以使用如下矩阵：

2 0 0 0 0 
0 1 0 0 0 
0 0 1 0 0 
0 0 0 1 0 

这将为您提供 0.4, 0.5, 0.8, 1 的向量（颜色）。从有限的测试来看，情况似乎如此，并且工作正常，但实际上我仍然遇到同样的问题（即白色获得着色）。进一步阅读告诉我，这是因为它对 RGB 值进行转换，而对于色调偏移，应首先将值转换为 HSL 值。因此，我可能可以编写一个类来读取图像并转换颜色，并使用新颜色重新绘制图像。这给 StateListDrawables 带来了另一个问题，因为我不确定如何在代码中获取这些内容并修改所有内容，以及这个过程有多慢。 ：/

嗯，好吧，所以我想我会遇到的另一个问题是矩阵是否可以用于将 RGB 转换为另一个具有亮度信息的颜色空间，例如 Lab 或 HSL？如果是这样，我只需乘以该转换的矩阵，然后对该矩阵进行色调调整，然后将该矩阵应用为 ColorFilter。

Answer 1

这就是我在游戏中使用的。这是在网站上的各种文章中找到的各个部分的汇编。致谢来自@see 链接的原作者。
请注意，颜色矩阵可以做更多的事情。包括反转等......

public class ColorFilterGenerator
{
    /**
 * Creates a HUE ajustment ColorFilter
 * @see http://groups.google.com/group/android-developers/browse_thread/thread/9e215c83c3819953
 * @see http://gskinner.com/blog/archives/2007/12/colormatrix_cla.html
 * @param value degrees to shift the hue.
 * @return
 */
public static ColorFilter adjustHue( float value )
{
    ColorMatrix cm = new ColorMatrix();

    adjustHue(cm, value);

    return new ColorMatrixColorFilter(cm);
}

/**
 * @see http://groups.google.com/group/android-developers/browse_thread/thread/9e215c83c3819953
 * @see http://gskinner.com/blog/archives/2007/12/colormatrix_cla.html
 * @param cm
 * @param value
 */
public static void adjustHue(ColorMatrix cm, float value)
{
    value = cleanValue(value, 180f) / 180f * (float) Math.PI;
    if (value == 0)
    {
        return;
    }
    float cosVal = (float) Math.cos(value);
    float sinVal = (float) Math.sin(value);
    float lumR = 0.213f;
    float lumG = 0.715f;
    float lumB = 0.072f;
    float[] mat = new float[]
    { 
            lumR + cosVal * (1 - lumR) + sinVal * (-lumR), lumG + cosVal * (-lumG) + sinVal * (-lumG), lumB + cosVal * (-lumB) + sinVal * (1 - lumB), 0, 0, 
            lumR + cosVal * (-lumR) + sinVal * (0.143f), lumG + cosVal * (1 - lumG) + sinVal * (0.140f), lumB + cosVal * (-lumB) + sinVal * (-0.283f), 0, 0,
            lumR + cosVal * (-lumR) + sinVal * (-(1 - lumR)), lumG + cosVal * (-lumG) + sinVal * (lumG), lumB + cosVal * (1 - lumB) + sinVal * (lumB), 0, 0, 
            0f, 0f, 0f, 1f, 0f, 
            0f, 0f, 0f, 0f, 1f };
    cm.postConcat(new ColorMatrix(mat));
}

protected static float cleanValue(float p_val, float p_limit)
{
    return Math.min(p_limit, Math.max(-p_limit, p_val));
}
}

为了完成这个我应该添加一个例子：

ImageView Sun = (ImageView)findViewById(R.id.sun);
Sun.setColorFilter(ColorFilterGenerator.adjustHue(162)); // 162 degree rotation

Answer 2

如果你想调整亮度、对比度、饱和度和色调，这里是完整的代码。享受！
非常感谢@RichardLalancette

public class ColorFilterGenerator {

private static double DELTA_INDEX[] = {
    0,    0.01, 0.02, 0.04, 0.05, 0.06, 0.07, 0.08, 0.1,  0.11,
    0.12, 0.14, 0.15, 0.16, 0.17, 0.18, 0.20, 0.21, 0.22, 0.24,
    0.25, 0.27, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, 0.40, 0.42,
    0.44, 0.46, 0.48, 0.5,  0.53, 0.56, 0.59, 0.62, 0.65, 0.68, 
    0.71, 0.74, 0.77, 0.80, 0.83, 0.86, 0.89, 0.92, 0.95, 0.98,
    1.0,  1.06, 1.12, 1.18, 1.24, 1.30, 1.36, 1.42, 1.48, 1.54,
    1.60, 1.66, 1.72, 1.78, 1.84, 1.90, 1.96, 2.0,  2.12, 2.25, 
    2.37, 2.50, 2.62, 2.75, 2.87, 3.0,  3.2,  3.4,  3.6,  3.8,
    4.0,  4.3,  4.7,  4.9,  5.0,  5.5,  6.0,  6.5,  6.8,  7.0,
    7.3,  7.5,  7.8,  8.0,  8.4,  8.7,  9.0,  9.4,  9.6,  9.8, 
    10.0
};

/**
 * @see http://groups.google.com/group/android-developers/browse_thread/thread/9e215c83c3819953
 * @see http://gskinner.com/blog/archives/2007/12/colormatrix_cla.html
 * @param cm
 * @param value
 */
public static void adjustHue(ColorMatrix cm, float value)
{
    value = cleanValue(value, 180f) / 180f * (float) Math.PI;
    if (value == 0){
        return;
    }

    float cosVal = (float) Math.cos(value);
    float sinVal = (float) Math.sin(value);
    float lumR = 0.213f;
    float lumG = 0.715f;
    float lumB = 0.072f;
    float[] mat = new float[]
    { 
            lumR + cosVal * (1 - lumR) + sinVal * (-lumR), lumG + cosVal * (-lumG) + sinVal * (-lumG), lumB + cosVal * (-lumB) + sinVal * (1 - lumB), 0, 0, 
            lumR + cosVal * (-lumR) + sinVal * (0.143f), lumG + cosVal * (1 - lumG) + sinVal * (0.140f), lumB + cosVal * (-lumB) + sinVal * (-0.283f), 0, 0,
            lumR + cosVal * (-lumR) + sinVal * (-(1 - lumR)), lumG + cosVal * (-lumG) + sinVal * (lumG), lumB + cosVal * (1 - lumB) + sinVal * (lumB), 0, 0, 
            0f, 0f, 0f, 1f, 0f, 
            0f, 0f, 0f, 0f, 1f };
    cm.postConcat(new ColorMatrix(mat));
}

public static void adjustBrightness(ColorMatrix cm, float value) {
    value = cleanValue(value,100);
    if (value == 0) {
        return;
    }

    float[] mat = new float[]
    { 
        1,0,0,0,value,
        0,1,0,0,value,
        0,0,1,0,value,
        0,0,0,1,0,
        0,0,0,0,1
    };
    cm.postConcat(new ColorMatrix(mat));
}

public static void adjustContrast(ColorMatrix cm, int value) {
    value = (int)cleanValue(value,100);
    if (value == 0) { 
        return; 
    }
    float x;
    if (value < 0) {
        x = 127 + (float) value / 100*127;
    } else {
        x = value % 1;
        if (x == 0) {
            x = (float)DELTA_INDEX[value];
        } else {
            //x = DELTA_INDEX[(p_val<<0)]; // this is how the IDE does it.
            x = (float)DELTA_INDEX[(value<<0)]*(1-x) + (float)DELTA_INDEX[(value<<0)+1] * x; // use linear interpolation for more granularity.
        }
        x = x*127+127;
    }

    float[] mat = new float[]
    { 
            x/127,0,0,0, 0.5f*(127-x),
            0,x/127,0,0, 0.5f*(127-x),
            0,0,x/127,0, 0.5f*(127-x),
            0,0,0,1,0,
            0,0,0,0,1
    };
    cm.postConcat(new ColorMatrix(mat));

}

public static void adjustSaturation(ColorMatrix cm, float value) {
    value = cleanValue(value,100);
    if (value == 0) {
        return;
    }

    float x = 1+((value > 0) ? 3 * value / 100 : value / 100);
    float lumR = 0.3086f;
    float lumG = 0.6094f;
    float lumB = 0.0820f;

    float[] mat = new float[]
    { 
        lumR*(1-x)+x,lumG*(1-x),lumB*(1-x),0,0,
        lumR*(1-x),lumG*(1-x)+x,lumB*(1-x),0,0,
        lumR*(1-x),lumG*(1-x),lumB*(1-x)+x,0,0,
        0,0,0,1,0,
        0,0,0,0,1
    };
    cm.postConcat(new ColorMatrix(mat));
}



protected static float cleanValue(float p_val, float p_limit)
{
    return Math.min(p_limit, Math.max(-p_limit, p_val));
}

public static ColorFilter adjustColor(int brightness, int contrast, int saturation, int hue){
    ColorMatrix cm = new ColorMatrix();
    adjustHue(cm, hue);
    adjustContrast(cm, contrast);
    adjustBrightness(cm, brightness);
    adjustSaturation(cm, saturation);

    return new ColorMatrixColorFilter(cm);
}
}

Answer 3

对于任何对如何使用 ColorMatrixColorFilter 感兴趣的人。我在这里使用的示例在画布上绘制位图时将每个像素都转换为红色。

类中的注释来自： http://developer.android.com/reference /android/graphics/ColorMatrix.html 这让您了解其工作原理

@Override
protected void onDraw(Canvas canvas) {

    // The matrix is stored in a single array, and its treated as follows: [ a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t ]
    // When applied to a color [r, g, b, a], the resulting color is computed as (after clamping) ;
    //   R' = a*R + b*G + c*B + d*A + e; 
    //   G' = f*R + g*G + h*B + i*A + j; 
    //   B' = k*R + l*G + m*B + n*A + o; 
    //   A' = p*R + q*G + r*B + s*A + t; 

    Paint paint = new Paint();
    float[] matrix = { 
        1, 1, 1, 1, 1, //red
        0, 0, 0, 0, 0, //green
        0, 0, 0, 0, 0, //blue
        1, 1, 1, 1, 1 //alpha
    };
    paint.setColorFilter(new ColorMatrixColorFilter(matrix));

    Rect source = new Rect(0, 0, 100, 100);
    Rect dest = new Rect(0, 0, 100, 100);

    Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.sampleimage);
    canvas.drawBitmap(bitmap , source, dest, paint);
}

Answer 4

下面的课程是对已经发布的答案的改进。这使得从位图读取和创建ColorFilter变得更加容易。

用法示例：

ImageView imageView = ...;
Drawable drawable = imageView.getDrawable();
ColorFilter colorFilter = ColorFilterGenerator.from(drawable).to(Color.RED);
imageView.setColorFilter(colorFilter);

---

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorFilter;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.PictureDrawable;
import android.widget.ImageView;

/**
 * Creates a {@link ColorMatrixColorFilter} to adjust the hue, saturation, brightness, or
 * contrast of an {@link Bitmap}, {@link Drawable}, or {@link ImageView}.
 * <p/>
 * Example usage:
 * <br/>
 * {@code imageView.setColorFilter(ColorFilterGenerator.from(Color.BLUE).to(Color.RED));}
 *
 * @author Jared Rummler <[email protected]>
 */
public class ColorFilterGenerator {

  // Based off answer from StackOverflow
  // See: http://stackoverflow.com/a/15119089/1048340

  private ColorFilterGenerator() {
    throw new AssertionError();
  }

  public static From from(Drawable drawable) {
    return new From(drawableToBitmap(drawable));
  }

  public static From from(Bitmap bitmap) {
    return new From(bitmap);
  }

  public static From from(int color) {
    return new From(color);
  }

  // --------------------------------------------------------------------------------------------

  private static final double DELTA_INDEX[] = {
      0, 0.01, 0.02, 0.04, 0.05, 0.06, 0.07, 0.08, 0.1, 0.11, 0.12, 0.14, 0.15, 0.16, 0.17, 0.18,
      0.20, 0.21, 0.22, 0.24, 0.25, 0.27, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, 0.40, 0.42, 0.44,
      0.46, 0.48, 0.5, 0.53, 0.56, 0.59, 0.62, 0.65, 0.68, 0.71, 0.74, 0.77, 0.80, 0.83, 0.86, 0.89,
      0.92, 0.95, 0.98, 1.0, 1.06, 1.12, 1.18, 1.24, 1.30, 1.36, 1.42, 1.48, 1.54, 1.60, 1.66, 1.72,
      1.78, 1.84, 1.90, 1.96, 2.0, 2.12, 2.25, 2.37, 2.50, 2.62, 2.75, 2.87, 3.0, 3.2, 3.4, 3.6,
      3.8, 4.0, 4.3, 4.7, 4.9, 5.0, 5.5, 6.0, 6.5, 6.8, 7.0, 7.3, 7.5, 7.8, 8.0, 8.4, 8.7, 9.0, 9.4,
      9.6, 9.8, 10.0
  };

  public static void adjustHue(ColorMatrix cm, float value) {
    value = cleanValue(value, 180f) / 180f * (float) Math.PI;
    if (value == 0) {
      return;
    }

    float cosVal = (float) Math.cos(value);
    float sinVal = (float) Math.sin(value);
    float lumR = 0.213f;
    float lumG = 0.715f;
    float lumB = 0.072f;
    float[] mat = new float[]{
        lumR + cosVal * (1 - lumR) + sinVal * (-lumR),
        lumG + cosVal * (-lumG) + sinVal * (-lumG),
        lumB + cosVal * (-lumB) + sinVal * (1 - lumB), 0, 0,
        lumR + cosVal * (-lumR) + sinVal * (0.143f),
        lumG + cosVal * (1 - lumG) + sinVal * (0.140f),
        lumB + cosVal * (-lumB) + sinVal * (-0.283f), 0, 0,
        lumR + cosVal * (-lumR) + sinVal * (-(1 - lumR)),
        lumG + cosVal * (-lumG) + sinVal * (lumG),
        lumB + cosVal * (1 - lumB) + sinVal * (lumB), 0, 0, 0f, 0f, 0f, 1f, 0f, 0f, 0f, 0f,
        0f, 1f
    };
    cm.postConcat(new ColorMatrix(mat));
  }

  public static void adjustBrightness(ColorMatrix cm, float value) {
    value = cleanValue(value, 100);
    if (value == 0) {
      return;
    }

    float[] mat = new float[]{
        1, 0, 0, 0, value, 0, 1, 0, 0, value, 0, 0, 1, 0, value, 0, 0, 0, 1, 0, 0, 0, 0, 0,
        1
    };
    cm.postConcat(new ColorMatrix(mat));
  }

  public static void adjustContrast(ColorMatrix cm, int value) {
    value = (int) cleanValue(value, 100);
    if (value == 0) {
      return;
    }
    float x;
    if (value < 0) {
      x = 127 + value / 100 * 127;
    } else {
      x = value % 1;
      if (x == 0) {
        x = (float) DELTA_INDEX[value];
      } else {
        x = (float) DELTA_INDEX[(value << 0)] * (1 - x)
            + (float) DELTA_INDEX[(value << 0) + 1] * x;
      }
      x = x * 127 + 127;
    }

    float[] mat = new float[]{
        x / 127, 0, 0, 0, 0.5f * (127 - x), 0, x / 127, 0, 0, 0.5f * (127 - x), 0, 0,
        x / 127, 0, 0.5f * (127 - x), 0, 0, 0, 1, 0, 0, 0, 0, 0, 1
    };
    cm.postConcat(new ColorMatrix(mat));

  }

  public static void adjustSaturation(ColorMatrix cm, float value) {
    value = cleanValue(value, 100);
    if (value == 0) {
      return;
    }

    float x = 1 + ((value > 0) ? 3 * value / 100 : value / 100);
    float lumR = 0.3086f;
    float lumG = 0.6094f;
    float lumB = 0.0820f;

    float[] mat = new float[]{
        lumR * (1 - x) + x, lumG * (1 - x), lumB * (1 - x), 0, 0, lumR * (1 - x),
        lumG * (1 - x) + x, lumB * (1 - x), 0, 0, lumR * (1 - x), lumG * (1 - x),
        lumB * (1 - x) + x, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1
    };
    cm.postConcat(new ColorMatrix(mat));
  }

  // --------------------------------------------------------------------------------------------

  private static float cleanValue(float p_val, float p_limit) {
    return Math.min(p_limit, Math.max(-p_limit, p_val));
  }

  private static float[] getHsv(int color) {
    float[] hsv = new float[3];
    Color.RGBToHSV(Color.red(color), Color.green(color), Color.blue(color), hsv);
    return hsv;
  }

  /**
   * Converts a {@link Drawable} to a {@link Bitmap}
   *
   * @param drawable
   *     The {@link Drawable} to convert
   * @return The converted {@link Bitmap}.
   */
  private static Bitmap drawableToBitmap(Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
      return ((BitmapDrawable) drawable).getBitmap();
    } else if (drawable instanceof PictureDrawable) {
      PictureDrawable pictureDrawable = (PictureDrawable) drawable;
      Bitmap bitmap = Bitmap.createBitmap(pictureDrawable.getIntrinsicWidth(),
          pictureDrawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
      Canvas canvas = new Canvas(bitmap);
      canvas.drawPicture(pictureDrawable.getPicture());
      return bitmap;
    }
    int width = drawable.getIntrinsicWidth();
    width = width > 0 ? width : 1;
    int height = drawable.getIntrinsicHeight();
    height = height > 0 ? height : 1;
    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);
    return bitmap;
  }

  /**
   * Calculate the average red, green, blue color values of a bitmap
   *
   * @param bitmap
   *     a {@link Bitmap}
   * @return
   */
  private static int[] getAverageColorRGB(Bitmap bitmap) {
    int width = bitmap.getWidth();
    int height = bitmap.getHeight();
    int size = width * height;
    int[] pixels = new int[size];
    int r, g, b;
    r = g = b = 0;
    bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
    for (int i = 0; i < size; i++) {
      int pixelColor = pixels[i];
      if (pixelColor == Color.TRANSPARENT) {
        size--;
        continue;
      }
      r += Color.red(pixelColor);
      g += Color.green(pixelColor);
      b += Color.blue(pixelColor);
    }
    r /= size;
    g /= size;
    b /= size;
    return new int[]{
        r, g, b
    };
  }

  /**
   * Calculate the average color value of a bitmap
   *
   * @param bitmap
   *     a {@link Bitmap}
   * @return
   */
  private static int getAverageColor(Bitmap bitmap) {
    int[] rgb = getAverageColorRGB(bitmap);
    return Color.argb(255, rgb[0], rgb[1], rgb[2]);
  }

  // Builder
  // --------------------------------------------------------------------------------------------

  public static final class Builder {

    int hue;

    int contrast;

    int brightness;

    int saturation;

    public Builder setHue(int hue) {
      this.hue = hue;
      return this;
    }

    public Builder setContrast(int contrast) {
      this.contrast = contrast;
      return this;
    }

    public Builder setBrightness(int brightness) {
      this.brightness = brightness;
      return this;
    }

    public Builder setSaturation(int saturation) {
      this.saturation = saturation;
      return this;
    }

    public ColorFilter build() {
      ColorMatrix cm = new ColorMatrix();
      adjustHue(cm, hue);
      adjustContrast(cm, contrast);
      adjustBrightness(cm, brightness);
      adjustSaturation(cm, saturation);
      return new ColorMatrixColorFilter(cm);
    }
  }

  public static final class From {

    final int oldColor;

    private From(Bitmap bitmap) {
      oldColor = getAverageColor(bitmap);
    }

    private From(int oldColor) {
      this.oldColor = oldColor;
    }

    public ColorFilter to(int newColor) {
      float[] hsv1 = getHsv(oldColor);
      float[] hsv2 = getHsv(newColor);
      int hue = (int) (hsv2[0] - hsv1[0]);
      int saturation = (int) (hsv2[1] - hsv1[1]);
      int brightness = (int) (hsv2[2] - hsv1[2]);
      return new ColorFilterGenerator.Builder()
          .setHue(hue)
          .setSaturation(saturation)
          .setBrightness(brightness)
          .build();
    }
  }

}

Answer 5

色调和 RGB 之间不存在线性关系。色调以 60° 块分段定义 (http://en.wikipedia.org/wiki/HSL_color_space#General_approach ），因此HSV和RGB之间不存在简单的矩阵转换。
要更改图像的色调，可以使用以下方法：

public Bitmap changeHue( Bitmap source, double hue ) {
    Bitmap result = Bitmap.createBitmap( source.getWidth(), source.getHeight(), source.getConfig() );

    float[] hsv = new float[3];
    for( int x = 0; x < source.getWidth(); x++ ) {
        for( int y = 0; y < source.getHeight(); y++ ) {
            int c = source.getPixel( x, y );
            Color.colorToHSV( c, hsv );
            hsv[0] = (float) ((hsv[0] + 360 * hue) % 360);
            c = (Color.HSVToColor( hsv ) & 0x00ffffff) | (c & 0xff000000);
            result.setPixel( x, y, c );
        }
    }

    return result;
}

Answer 6

我认为这个方法会给你你想要的：

http ://android.okhelp.cz/hue-color-colored-filter-bitmap-image-android-example/

bitmapOrg.setColorFilter(Color.RED, PorterDuff.Mode.MULTIPLY);

Answer 7

与其他答案一样，我使用颜色矩阵来实现此行为，但您可以传入常规 Android 颜色资源。该矩阵将颜色映射到图像值和白色之间的范围。

/**
 * Color everything that isn't white, the tint color
 * @param tintColor the color to tint the icon
 */
public void setInverseMultiplyFilter(Drawable imgCopy, @ColorInt int tintColor) {

    Drawable imgCopy = imageView.getDrawable().getConstantState().newDrawable();

    float colorRed = Color.red(tintColor) / 255f;
    float colorGreen = Color.green(tintColor) / 255f;
    float colorBlue = Color.blue(tintColor) / 255f;

    imgCopy.setColorFilter(new ColorMatrixColorFilter(new ColorMatrix(new float[]{
            1 - colorRed, 0,              0,             0,     colorRed * 255,
            0,            1 - colorGreen, 0,             0,     colorGreen * 255,
            0,            0,              1 - colorBlue, 0,     colorBlue * 255,
            0,            0,              0,             Color.alpha(tintColor) / 255f, 0,
    })));

    imageView.setImageDrawable(imgCopy);
    imageView.invalidate();
}

Answer 8

我根据以下代码片段制作了一个小小的 ColorMatrixFilter 测试器：

private Bitmap setColorFilter(Bitmap drawable) {                
            Bitmap grayscale  = Bitmap.createBitmap(drawable.getWidth(), drawable.getHeight(), drawable.getConfig());
            //if(isRenderMode) bOriginal.recycle();
            Canvas c = new Canvas(grayscale );
            Paint p = new Paint();

            final ColorMatrix matrixA = new ColorMatrix();
            matrixA.setSaturation(sauturationValue/2);


            float[] mx = {
                    r1Value,  r2Value,  r3Value,  r4Value,  r5Value,
                    g1Value,  g2Value,  g3Value,  g4Value,  g5Value,
                    b1Value,  b2Value,  b3Value,  b4Value,  b5Value,
                    a1Value,  a2Value,  a3Value,  a4Value,  a5Value
                    };
                    final ColorMatrix matrixB = new ColorMatrix(mx);

            matrixA.setConcat(matrixB, matrixA);

            final ColorMatrixColorFilter filter = new ColorMatrixColorFilter(matrixA);
            p.setColorFilter(filter);
            c.drawBitmap(drawable, 0, 0, p);
            return grayscale;               
        } 

您可以在此处查看：
https://play.google.com/store/apps/details ?id=org.vaelostudio.colormatrixtester

Answer 9

尽管使用 ColorMatrix 可以实现很多有用的效果，但我个人会考虑将 ColorMap[] 与 ImageAttributes 一起使用。通过这样做，我们可以定义哪些颜色应该替换为哪些颜色。

Answer 10

我解决这个问题的方法是从灰度图像开始。

原创 ---> grayImage

你可以在 Photoshop 中轻松完成，或者如果你需要用代码完成，你可以使用以下方法。

private fun changeImageToGreyScale() {
   val matrix = ColorMatrix()
   matrix.setSaturation(0f)

   val originalBitmap = BitmapFactory.decodeResource(resources, originalImageID)
   val bitmapCopy = Bitmap.createBitmap(originalBitmap.width, 
   originalBitmap.height, Bitmap.Config.ARGB_8888)
   val canvas = Canvas(bitmapCopy)

   val paint = Paint()
   val colorFilter = ColorMatrixColorFilter(matrix)
   paint.colorFilter = colorFilter
   canvas.drawBitmap(originalBitmap, 0f, 0f, paint)
   grayScaleImage = bitmapCopy
}

获得灰度图像后，您可以使用 PorterDuff OVERLAY 模式添加所需的颜色。

private fun applyFilterToImage() {

    val bitmapCopy = Bitmap.createBitmap(grayScaleImage.width, grayScaleImage.height, Bitmap.Config.ARGB_8888)
    val canvas = Canvas(bitmapCopy)

    val rnd = java.util.Random()
    val randomColor = Color.rgb(rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256))

    val paint = Paint()
    val porterDuffMode = PorterDuff.Mode.OVERLAY
    paint.colorFilter = PorterDuffColorFilter(randomColor, porterDuffMode)

    val maskPaint = Paint()
    maskPaint. xfermode = PorterDuffXfermode(PorterDuff.Mode.DST_ATOP)

    canvas.drawBitmap(grayScaleImage, 0f, 0f, paint) 

    /**
    Note OVERLAY will disregard the alpha channel and will turn transparent 
    pixels into the randomColor. To resolve this I clip out that transparent area by 
    drawing the image again with the DST_ATOP XferMode
    **/
    canvas.drawBitmap(grayScaleImage, 0f, 0f, maskPaint)

    imageView.setImageBitmap(bitmapCopy)
}

上面结果如下
randomColorGif

Answer 11

为了支持完整的 360 度色调，我将接受的答案中的以下行更改为：

从：

value = cleanValue(value, 180f) / 180f * (float) Math.PI;

到：

value = cleanValue(value, 360f) / 360f * (float) Math.PI * 2;