在图像上找到最大颜色的问题

Question

这是查找图像中最大颜色的代码，但它总是返回错误的坐标。 代码搜索并找到最大值并返回图像的二维数组，但是当他找到最大颜色时，它会创建一个十字并返回带有十字的图像，只是为了知道最大颜色的位置在哪里。

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "dip.h"

#define INPUT_FILENAME      "chest339x339.raw"      
#define OUTPUT_FILENAME     "task_4_chest339x339_out.raw"   
#define ROWS                339                     
#define COLUMNS             339                     
#define GREYLEVELS          256                     
#define OUTPUT_ROWS         ROWS                
#define OUTPUT_COLUMNS      COLUMNS 


unsigned char** createImage(unsigned char** inputImage, int rows, int columns, int x_max, int y_max ) ;


int main(void) {


     unsigned char  **inputImage,                   
                    **outputImage;

     int x_max=0,y_max=0;

     FILE    *inputFile,                                            
             *outputFile;

  
    inputImage = allocateImage(ROWS, COLUMNS);
    inputImage = loadImage(INPUT_FILENAME, ROWS, COLUMNS);
    outputImage = createImage(inputImage,ROWS, COLUMNS,x_max,y_max);
    saveImage( OUTPUT_FILENAME,outputImage ,ROWS, COLUMNS);
    deallocateImage(inputImage, ROWS);
    deallocateImage(outputImage, ROWS);
    
    printf("The coordinates are (x,y)=(%d,%d) .\n",x_max,y_max);
}

unsigned char** createImage(unsigned char** inputImage, int rows, int columns, int x_max, int y_max ) {

    int i,j;
    float temp=0.0;
    unsigned char **outputImage = allocateImage(rows, columns);
    
    int max = -1 ;

    for( i= 0; i< rows; i++ ) {

        for( j= 0; j< columns; j++ ) {
               
            outputImage[i][j] = inputImage[i][j];

           if ( outputImage[i][j] > max ) {

                outputImage[i][j] = max;
                x_max = i;
                y_max = j;
           }  
    printf("The coordinates are %d  .\n",outputImage[i][j]); 
        }
    }
    
    printf("The coordinates are %d (x,y)=(%d,%d) .\n",max,x_max,y_max);

     outputImage[x_max-1][j] = 0;
     outputImage[x_max+1][j] = 0;
     outputImage[i][y_max-1] = 0;
     outputImage[i][y_max+1] = 0;        

    return outputImage;
}

这是库

#include <stdio.h>
#include <stdlib.h>

unsigned char **allocateImage(int rows, int columns)
{
      unsigned char **image = (unsigned char **)malloc(rows * sizeof(unsigned char *));
      int i;
      for (i = 0; i < rows; i++)
      {
          image[i] = (unsigned char *)malloc(columns * sizeof(unsigned char));
      }
      return image;
}

void deallocateImage(unsigned char **image, int rows)
{
     int i;
     for (i = 0; i < rows; i++)
     {
         free(image[i]);
     }
     free(image);     
}

unsigned char **loadImage(char *filename, int rows, int columns)
{
    FILE *inputFile;
    unsigned char **image = allocateImage(rows, columns);

    int i,j;    
    if ( ((inputFile = fopen(filename,"rb")) != NULL))
    {
        for  (i = 0; i < rows; i++)
        {
            for  (j = 0; j < columns; j++)
            {
                fscanf(inputFile, "%c", &image[i][j]);
            }
        }
    } 
    else
    {
        printf("Error loading image.");
    }
    fclose(inputFile);
    return image;
}


void saveImage(char *filename, unsigned char **image, int rows, int columns)
{
    FILE *outputFile;
     
    int i,j;
    if ( ((outputFile = fopen(filename,"wb")) != NULL))
    {
        for  (i = 0; i < rows; i++)
        {
            for  (j = 0; j < columns; j++)
            {
                fprintf(outputFile, "%c", image[i][j]);
            }
        }
    } 
    else
    {
        printf("Error saving image.");
    }
    fclose(outputFile);
}

在此处输入图像描述

Answer 1

1. 头文件用于声明，所有定义都应在您编译的 .c 文件中。

2. 使用x_max &的地址调用createImage() y_max。

unsigned char** createImage(inputImage,ROWS, COLUMNS, &x_max, &y_max);

3. 然后函数接受地址和用所需的像素索引填充它们：

unsigned char** 
createImage (unsigned char** inputImage, int rows, int columns, int* x_max, int* y_max) {
    int i, j;
    float temp = 0.0;
    unsigned char **outputImage = allocateImage (rows, columns);
    int max = -1 ;
    
    for (i = 0; i < rows; i++) {
        for (j = 0; j < columns; j++) {
            outputImage[i][j] = inputImage[i][j];
            outputImage[i][j] = inputImage[i][j];
            if (outputImage[i][j] > max) {
//                outputImage[i][j] = max;
                max = outputImage[i][j] = max; // update max value
                *x_max = i;
                *y_max = j;
            }
            printf ("The coordinates are %d  .\n", outputImage[i][j]);
        }
    }
    printf ("The coordinates are %d (x,y)=(%d,%d) .\n", max, *x_max, *y_max);
    
    outputImage[*x_max - 1][j] = 0;
    outputImage[*x_max + 1][j] = 0;
    outputImage[i][*y_max - 1] = 0;
    outputImage[i][*y_max + 1] = 0;
    
    return outputImage;
}

4. 在单色图像中，尤其是在 X 射线图像中，您会在多个位置找到最大值（白色）像素。