C语言实现直方图统计和直方图均衡化

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C语言实现直方图统计

#include <stdio.h>

void DrawHistogram(int nArray[], int nCount, char ch) {

    for (int i = 0; i < nCount; i++) {
        for (int j = 0; j < nArray[i]; j++)
            printf("%c", ch);
        printf(" %d\n", nArray[i]);
    }
    printf("\n");
}

void CountRangeItems(int dArray[], int nDataItems, int nArray[]) {
    for (int i = 0; i < nDataItems; i++) {
        if (dArray[i] <= 160) nArray[0]++;
        else if (dArray[i] < 165) nArray[1]++;
        else if (dArray[i] < 170) nArray[2]++;
        else if (dArray[i] < 175) nArray[3]++;
        else if (dArray[i] > 175) nArray[4]++;
    }
}

int main() {
    int height[] = { 185, 176, 165, 169, 160, 152, 173, 196, 178, 169, 166, 182, 181, 171, 159, 163, 168 };
    int nArray[5] = { 0 };
    int nCount = 5, size = sizeof(height) / sizeof(height[0]);
    CountRangeItems(height, size, nArray);
    DrawHistogram(nArray, nCount, '*');
    getchar();
    return 0;
}

C语言实现直方图均衡化

#include <stdio.h>

void DrawHistogram(int nArray[], int nCount, char ch) {

    for (int i = 0; i < nCount; i++) {
        for (int j = 0; j < nArray[i]; j++)
            printf("%c", ch);
        printf(" %d\n", nArray[i]);
    }
    printf("\n");
}

void CountRangeItems(int dArray[], int nDataItems, int nArray[]) {
    for (int i = 0; i < nDataItems; i++) {
        if (dArray[i] <= 160) nArray[0]++;
        else if (dArray[i] < 165) nArray[1]++;
        else if (dArray[i] < 170) nArray[2]++;
        else if (dArray[i] < 175) nArray[3]++;
        else if (dArray[i] > 175) nArray[4]++;
    }
}

int main() {
    int height[] = { 158, 176, 165, 159, 160, 182, 173, 159, 178, 169, 166, 182, 179, 171, 159, 166, 157, 176, 171, 159 };
    int nArray[5] = { 0 };
    int nCount = 5, size = sizeof(height) / sizeof(height[0]);
    CountRangeItems(height, size, nArray);
    DrawHistogram(nArray, nCount, '*');
    printf("\n");

    //直方图归一化
    float histPDF[] = { 0 };
    printf("直方图归一化：\n");
    for (int i = 0; i < nCount; i++)
    {
        histPDF[i] = float(nArray[i])/20.0;
        //printf(" (%d) ", nArray[i]);
        printf("%.2f ", histPDF[i]);
    }

    //累积直方图
    printf("\n累积直方图：\n");
    float histCDF[] = { 0 };
    for (int i = 0; i < nCount; i++)
    {
        if (0 == i)
            histCDF[i] = histPDF[i];
        else 
            histCDF[i] = histCDF[i - 1] + histPDF[i];
        printf("%.2f ",histCDF[i]);

    }
    //直方图均衡化，映射
    printf("\n直方图均衡化：\n");
    int histEQU[] = {0};
    for (int i = 0; i < nCount; i++)
    {
        histEQU[i] = (int)(5.0 * histCDF[i] + 0.5);
        printf("%d ",histEQU[i]);
    }
    getchar();
    return 0;
}