图像处理---LoMo

来源：互联网发布：成功的网络促销编辑：程序博客网时间：2024/05/16 11:09

所谓Lomo效果无非就是四角变暗，然后加上颜色矩阵变换。

以下是通过c代码实现的Lomo效果，效果有待优化：

/** LOMO效果 */jintArray ToLOMO(JNIEnv *env, jobject obj, jintArray srcPixels, jint width,        jint height, jfloat factor){    jint* pixels = NULL;    pixels = env->GetIntArrayElements(srcPixels, JNI_FALSE);    if (pixels == NULL)    {        return srcPixels;    }    int size = width * height;    int result[size];    int ratio =            width > height ? height * 32768 / width : width * 32768 / height;    int cx = width >> 1;    int cy = height >> 1;    int max = cx * cx + cy * cy;    int min = (int) (max * (1 - 0.8f));    int diff = max - min;    for (int i = 0; i < height; i++)    {        for (int j = 0; j < width; j++)        {            int current_color = pixels[i * width + j];            int r0 = red(current_color);            int g0 = green(current_color);            int b0 = blue(current_color);            int a0 = alpha(current_color);            int value = r0 < 128 ? r0 : 256 - r0;            int newR = (value * value * value) / 64 / 256;            newR = r0 < 128 ? newR : 255 - newR;            value = g0 < 128 ? g0 : 256 - g0;            int newG = (value * value) / 128;            newG = (g0 < 128 ? newG : 255 - newG);            int newB = b0 / 2 + 0x25;            /*****************边缘黑暗**************/            int dx = cx - j;            int dy = cy - i;            if (width > height)            {                dx = (dx * ratio) >> 15;            } else            {                dy = (dy * ratio) >> 15;            }            int distSq = dx * dx + dy * dy;            if (distSq > min)            {                int v = ((max - distSq) << 8) / diff;                v *= v;                int ri = (int) (newR * v) >> 16;                int gi = (int) (newG * v) >> 16;                int bi = (int) (newB * v) >> 16;                newR = ri > 255 ? 255 : (ri < 0 ? 0 : ri);                newG = gi > 255 ? 255 : (gi < 0 ? 0 : gi);                newB = bi > 255 ? 255 : (bi < 0 ? 0 : bi);            }            /**********************边缘黑暗end*****************/            current_color = ARGB(a0, newR, newG, newB);            result[i * width + j] = current_color;        }    }    jintArray resultArray = env->NewIntArray(size);    env->SetIntArrayRegion(resultArray, 0, size, result);    env->ReleaseIntArrayElements(srcPixels, pixels, 0);    return resultArray;}

以上仅供参考，但是效率不是很高，不过还有一种实现方式，就是利用图层混合处理算法，此算法等我总结出来释放demo

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