#include "user_image_process.h"

IFX_ALIGN(4) uint8 image_binary_1[MT9V03X_1_H][MT9V03X_1_W];

int user_otsu_threshold(uint8 *image, uint16 col, uint16 row)
{
    #define GRAYSCALE 256
    uint16 width = col;
    uint16 height = row;
    int pixelCount[GRAYSCALE];
    float pixelPro[GRAYSCALE];
    int i, j;
    int pixelSum = width * height / 4;
    int threshold = 0;
    uint8 *data = image;

    for (i = 0; i < GRAYSCALE; i++)
    {
        pixelCount[i] = 0;
        pixelPro[i] = 0;
    }

    uint32 gray_sum = 0;
    for (i = 0; i < height; i += 2)
    {
        for (j = 0; j < width; j += 2)
        {
            pixelCount[(int)data[i * width + j]]++;
            gray_sum += (int)data[i * width + j];
        }
    }

    for (i = 0; i < GRAYSCALE; i++)
    {
        pixelPro[i] = (float)pixelCount[i] / pixelSum;
    }

    float w0, w1, u0tmp, u1tmp, u0, u1, u, deltaTmp, deltaMax = 0;
    w0 = w1 = u0tmp = u1tmp = u0 = u1 = u = deltaTmp = 0;

    for (j = 0; j < GRAYSCALE; j++)
    {
        w0 += pixelPro[j];
        u0tmp += j * pixelPro[j];
        w1 = 1 - w0;

        /* 防止除零: 某一类为空时跳过该阈值 */
        if (w0 < 1e-6f || w1 < 1e-6f)
            continue;

        u1tmp = (float)gray_sum / pixelSum - u0tmp;

        u0 = u0tmp / w0;
        u1 = u1tmp / w1;
        u = u0tmp + u1tmp;

        deltaTmp = w0 * (u0 - u) * (u0 - u) + w1 * (u1 - u) * (u1 - u);

        if (deltaTmp > deltaMax)
        {
            deltaMax = deltaTmp;
            threshold = j;
        }
    }

    return threshold;
}

void user_image_binarize(uint8 *src_image, uint8 (*dst_image)[MT9V03X_1_W], uint16 col, uint16 row, int threshold)
{
    uint16 i, j;

    for (i = 0; i < row; i++)
    {
        for (j = 0; j < col; j++)
        {
            dst_image[i][j] = (src_image[i * col + j] >= (uint8)threshold) ? IMG_WHITE : IMG_BLACK;
        }
    }
}

void user_image_denoise(uint8 (*image)[MT9V03X_1_W], uint16 col, uint16 row)
{
    uint16 i, j;
    static uint8 buf[MT9V03X_1_H][MT9V03X_1_W];

    for (i = 0; i < row; i++) {
        for (j = 0; j < col; j++) {
            buf[i][j] = image[i][j];
        }
    }

    for (i = 1; i < row - 1; i++) {
        for (j = 1; j < col - 1; j++) {
            int cnt = 0;
            if (buf[i-1][j-1] == IMG_WHITE) cnt++;
            if (buf[i-1][j  ] == IMG_WHITE) cnt++;
            if (buf[i-1][j+1] == IMG_WHITE) cnt++;
            if (buf[i  ][j-1] == IMG_WHITE) cnt++;
            if (buf[i  ][j  ] == IMG_WHITE) cnt++;
            if (buf[i  ][j+1] == IMG_WHITE) cnt++;
            if (buf[i+1][j-1] == IMG_WHITE) cnt++;
            if (buf[i+1][j  ] == IMG_WHITE) cnt++;
            if (buf[i+1][j+1] == IMG_WHITE) cnt++;

            image[i][j] = (cnt >= 5) ? IMG_WHITE : IMG_BLACK;
        }
    }
}