Android图片特效:黑白特效、圆角效果、高斯模糊
1.黑白效果
/**
* 将彩色图转换为黑白图
*
* @param 位图
* @return 返回转换好的位图
*/
public static bitmap converttoblackwhite(bitmap bmp) {
int width = bmp.getwidth(); // 获取位图的宽
int height = bmp.getheight(); // 获取位图的高
int[] pixels = new int[width * height]; // 通过位图的大小创建像素点数组
bmp.getpixels(pixels, 0, width, 0, 0, width, height);
int alpha = 0xff << 24;
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) {
int grey = pixels[width * i + j];
int red = ((grey & 0x00ff0000) >> 16);
int green = ((grey & 0x0000ff00) >> 8);
int blue = (grey & 0x000000ff);
grey = (int) (red * 0.3 + green * 0.59 + blue * 0.11);
grey = alpha | (grey << 16) | (grey << 8) | grey;
pixels[width * i + j] = grey;
}
}
bitmap newbmp = bitmap.createbitmap(width, height, config.rgb_565);
newbmp.setpixels(pixels, 0, width, 0, 0, width, height);
return newbmp;
}
2.图片圆角
/**
* 转换成圆角
*
* @param bmp
* @param roundpx
* @return
*/
public static bitmap converttoroundedcorner(bitmap bmp, float roundpx) {
bitmap newbmp = bitmap.createbitmap(bmp.getwidth(), bmp.getheight(),
config.argb_8888);
// 得到画布
canvas canvas = new canvas(newbmp);
final int color = 0xff424242;
final paint paint = new paint();
final rect rect = new rect(0, 0, bmp.getwidth(), bmp.getheight());
final rectf rectf = new rectf(rect);
paint.setantialias(true);
canvas.drawargb(0, 0, 0, 0);
paint.setcolor(color);
// 第二个和第三个参数一样则画的是正圆的一角,否则是椭圆的一角
canvas.drawroundrect(rectf, roundpx, roundpx, paint);
paint.setxfermode(new porterduffxfermode(mode.src_in));
canvas.drawbitmap(bmp, rect, rect, paint);
return newbmp;
}
3.高斯模糊
/**
* 高斯模糊
*
* @param bmp
* @return
*/
public static bitmap converttoblur(bitmap bmp) {
// 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 newbmp = 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 + pixr * gauss[idx];
newg = newg + pixg * gauss[idx];
newb = newb + 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;
}
}
newbmp.setpixels(pixels, 0, width, 0, 0, width, height);
return newbmp;
}
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