android 图片特效处理之模糊效果
这篇将讲到图片特效处理的模糊效果。跟前面一样是对像素点进行处理,算法是通用的,但耗时会更长,至于为什么,看了下面的代码你就会明白。
算法:
一、简单算法:将像素点周围八个点包括自身一共九个点的RGB值分别相加后平均,作为当前像素点的RGB值,即可实现效果。
举例:
ABC
DEF
GHI
假如当前点是E,那么会有:
- E.r = (A.r + B.r + C.r + D.r + E.r + F.r + G.r + H.r + I.r) /9 // r表示的是E像素点RGB值的R值
- E.r = (A.r + B.r + C.r + D.r + E.r + F.r + G.r + H.r + I.r) / 9 // r表示的是E像素点RGB值的R值
E像素点的GB值类似。
二、采用高斯模糊:
高斯矩阵:
- int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 };
- int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 };
算法是:将九个点的RGB值分别与高斯矩阵中的对应项相乘的和,然后再除以一个相应的值作为当前像素点的RGB值。
举例:(还是上面的九个点)
假如当前点是E,那么会有:
- int delta = 16;
- E.r =( A.r * gauss[0] + B.r * gauss[1] + C.r * gauss[2] + D.r * gauss[3] + E.r * gauss[4] + F.r * gauss[5] + G.r * gauss[6] + H.r * gauss[7] + I.r * gauss[8]) / delta
- int delta = 16;
- E.r =( A.r * gauss[0] + B.r * gauss[1] + C.r * gauss[2] + D.r * gauss[3] + E.r * gauss[4] + F.r * gauss[5] + G.r * gauss[6] + H.r * gauss[7] + I.r * gauss[8]) / delta
E像素点的GB值类似,delta的取值貌似没有规定值,可以自己设置任意值,但要想达到效果,能设的值很少,下面图片是值为16的效果。
处理效果:
原图片:
处理后:
两种处理方式的代码:
- /**
- * 模糊效果
- * @param bmp
- * @return
- */
- private Bitmap blurImage(Bitmap bmp)
- {
- int width = bmp.getWidth();
- int height = bmp.getHeight();
- Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
- int pixColor = 0;
- int newR = 0;
- int newG = 0;
- int newB = 0;
- int newColor = 0;
- int[][] colors = new int[9][3];
- for (int i = 1, length = width - 1; i < length; i++)
- {
- for (int k = 1, len = height - 1; k < len; k++)
- {
- for (int m = 0; m < 9; m++)
- {
- int s = 0;
- int p = 0;
- switch(m)
- {
- case 0:
- s = i - 1;
- p = k - 1;
- break;
- case 1:
- s = i;
- p = k - 1;
- break;
- case 2:
- s = i + 1;
- p = k - 1;
- break;
- case 3:
- s = i + 1;
- p = k;
- break;
- case 4:
- s = i + 1;
- p = k + 1;
- break;
- case 5:
- s = i;
- p = k + 1;
- break;
- case 6:
- s = i - 1;
- p = k + 1;
- break;
- case 7:
- s = i - 1;
- p = k;
- break;
- case 8:
- s = i;
- p = k;
- }
- pixColor = bmp.getPixel(s, p);
- colors[m][0] = Color.red(pixColor);
- colors[m][1] = Color.green(pixColor);
- colors[m][2] = Color.blue(pixColor);
- }
- for (int m = 0; m < 9; m++)
- {
- newR += colors[m][0];
- newG += colors[m][1];
- newB += colors[m][2];
- }
- newR = (int) (newR / 9F);
- newG = (int) (newG / 9F);
- newB = (int) (newB / 9F);
- newR = Math.min(255, Math.max(0, newR));
- newG = Math.min(255, Math.max(0, newG));
- newB = Math.min(255, Math.max(0, newB));
- newColor = Color.argb(255, newR, newG, newB);
- bitmap.setPixel(i, k, newColor);
- newR = 0;
- newG = 0;
- newB = 0;
- }
- }
- return bitmap;
- }
- /**
- * 柔化效果(高斯模糊)(优化后比上面快三倍)
- * @param bmp
- * @return
- */
- private Bitmap blurImageAmeliorate(Bitmap bmp)
- {
- long start = System.currentTimeMillis();
- // 高斯矩阵
- int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 };
- int width = bmp.getWidth();
- int height = bmp.getHeight();
- Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
- int pixR = 0;
- int pixG = 0;
- int pixB = 0;
- int pixColor = 0;
- int newR = 0;
- int newG = 0;
- int newB = 0;
- int delta = 16; // 值越小图片会越亮,越大则越暗
- int idx = 0;
- int[] pixels = new int[width * height];
- bmp.getPixels(pixels, 0, width, 0, 0, width, height);
- for (int i = 1, length = height - 1; i < length; i++)
- {
- for (int k = 1, len = width - 1; k < len; k++)
- {
- idx = 0;
- for (int m = -1; m <= 1; m++)
- {
- for (int n = -1; n <= 1; n++)
- {
- pixColor = pixels[(i + m) * width + k + n];
- pixR = Color.red(pixColor);
- pixG = Color.green(pixColor);
- pixB = Color.blue(pixColor);
- newR = newR + (int) (pixR * gauss[idx]);
- newG = newG + (int) (pixG * gauss[idx]);
- newB = newB + (int) (pixB * gauss[idx]);
- idx++;
- }
- }
- newR /= delta;
- newG /= delta;
- newB /= delta;
- newR = Math.min(255, Math.max(0, newR));
- newG = Math.min(255, Math.max(0, newG));
- newB = Math.min(255, Math.max(0, newB));
- pixels[i * width + k] = Color.argb(255, newR, newG, newB);
- newR = 0;
- newG = 0;
- newB = 0;
- }
- }
- bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
- long end = System.currentTimeMillis();
- Log.d("may", "used time="+(end - start));
- return bitmap;
- }
- /**
- * 模糊效果
- * @param bmp
- * @return
- */
- private Bitmap blurImage(Bitmap bmp)
- {
- int width = bmp.getWidth();
- int height = bmp.getHeight();
- Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
- int pixColor = 0;
- int newR = 0;
- int newG = 0;
- int newB = 0;
- int newColor = 0;
- int[][] colors = new int[9][3];
- for (int i = 1, length = width - 1; i < length; i++)
- {
- for (int k = 1, len = height - 1; k < len; k++)
- {
- for (int m = 0; m < 9; m++)
- {
- int s = 0;
- int p = 0;
- switch(m)
- {
- case 0:
- s = i - 1;
- p = k - 1;
- break;
- case 1:
- s = i;
- p = k - 1;
- break;
- case 2:
- s = i + 1;
- p = k - 1;
- break;
- case 3:
- s = i + 1;
- p = k;
- break;
- case 4:
- s = i + 1;
- p = k + 1;
- break;
- case 5:
- s = i;
- p = k + 1;
- break;
- case 6:
- s = i - 1;
- p = k + 1;
- break;
- case 7:
- s = i - 1;
- p = k;
- break;
- case 8:
- s = i;
- p = k;
- }
- pixColor = bmp.getPixel(s, p);
- colors[m][0] = Color.red(pixColor);
- colors[m][1] = Color.green(pixColor);
- colors[m][2] = Color.blue(pixColor);
- }
- for (int m = 0; m < 9; m++)
- {
- newR += colors[m][0];
- newG += colors[m][1];
- newB += colors[m][2];
- }
- newR = (int) (newR / 9F);
- newG = (int) (newG / 9F);
- newB = (int) (newB / 9F);
- newR = Math.min(255, Math.max(0, newR));
- newG = Math.min(255, Math.max(0, newG));
- newB = Math.min(255, Math.max(0, newB));
- newColor = Color.argb(255, newR, newG, newB);
- bitmap.setPixel(i, k, newColor);
- newR = 0;
- newG = 0;
- newB = 0;
- }
- }
- return bitmap;
- }
- /**
- * 柔化效果(高斯模糊)(优化后比上面快三倍)
- * @param bmp
- * @return
- */
- private Bitmap blurImageAmeliorate(Bitmap bmp)
- {
- long start = System.currentTimeMillis();
- // 高斯矩阵
- int[] gauss = new int[] { 1, 2, 1, 2, 4, 2, 1, 2, 1 };
- int width = bmp.getWidth();
- int height = bmp.getHeight();
- Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
- int pixR = 0;
- int pixG = 0;
- int pixB = 0;
- int pixColor = 0;
- int newR = 0;
- int newG = 0;
- int newB = 0;
- int delta = 16; // 值越小图片会越亮,越大则越暗
- int idx = 0;
- int[] pixels = new int[width * height];
- bmp.getPixels(pixels, 0, width, 0, 0, width, height);
- for (int i = 1, length = height - 1; i < length; i++)
- {
- for (int k = 1, len = width - 1; k < len; k++)
- {
- idx = 0;
- for (int m = -1; m <= 1; m++)
- {
- for (int n = -1; n <= 1; n++)
- {
- pixColor = pixels[(i + m) * width + k + n];
- pixR = Color.red(pixColor);
- pixG = Color.green(pixColor);
- pixB = Color.blue(pixColor);
- newR = newR + (int) (pixR * gauss[idx]);
- newG = newG + (int) (pixG * gauss[idx]);
- newB = newB + (int) (pixB * gauss[idx]);
- idx++;
- }
- }
- newR /= delta;
- newG /= delta;
- newB /= delta;
- newR = Math.min(255, Math.max(0, newR));
- newG = Math.min(255, Math.max(0, newG));
- newB = Math.min(255, Math.max(0, newB));
- pixels[i * width + k] = Color.argb(255, newR, newG, newB);
- newR = 0;
- newG = 0;
- newB = 0;
- }
- }
- bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
- long end = System.currentTimeMillis();
- Log.d("may", "used time="+(end - start));
- return bitmap;
- }