C 创建 PGM 图像的参数编号

Question

我必须用 C 为大学做一个任务。程序在 PGM 中创建图像 format.The 程序编译成功，但是，我不能运行程序正确。在主函数的开头，if 运算符需要 2 个 argc，但每次我尝试运行程序时，我只有一个 argc，我得到结果

“错误：参数丢失或错误，使用 a3 [图像文件]”

密码是：

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <math.h>

const double PI = 3.1415926535897932;

int** loadImage (const char *filename, int* width, int* height);
bool saveImage (const char *filename, int **pixels,
                const unsigned int width, const unsigned int height);

/* *** task (a) *** */

int normalize(int value) {
  return 0;    // Dummy return
}

/* *** task (b) *** */

int** createImage(unsigned int width, unsigned int height, int value){
  
  return NULL;    // Dummy return
}

/* *** task (c) *** */

void freeImage(int** pixels, unsigned int width, unsigned int height){
  
}

/* *** task (d) *** */

int** inverter (int **pixels, int width, int height)
{
  
  return NULL;    // Dummy return
}

/* *** task (e) *** */

int** laplace (int **pixels, int width, int height)
{
  
  return NULL;    // Dummy return
}

/* *** task (f) *** */

int** rotate (int** pixels, int width, int height, double angle, int background)
{

  return NULL;    // Dummy return
}

int main (int argc, char **argv)
{
  if (argc == 2)
  {
    int width=0, height=0;
    int **image = loadImage (argv[1], &width, &height);
    if (image != NULL)
    {
      int **image1 = inverter (image, width, height);
      int **image2 = laplace (image, width, height);
      int **image3 = rotate (image, width, height, 150, 128);

      saveImage ("image0.pgm", image,  width, height);
      saveImage ("image1.pgm", image1, width, height);
      saveImage ("image2.pgm", image2, width, height);
      saveImage ("image3.pgm", image3, width, height);

      freeImage (image, width, height);
      freeImage (image1, width, height);
      freeImage (image2, width, height);
      freeImage (image3, width, height);
    }
  }
  else {
    printf ("Error: missing or bad parameters, usage a3 [imagefile]\n");
  }
  return 0;
}

/* *** Bild aus Datei laden *** */
int** loadImage (const char *filename, int* width, int* height)
{
  const char *delimiter = " \n\r\t";
  FILE *file = fopen (filename, "rt");
  int** pixels;
  bool isValid = true;

  if (file != NULL)
  {
    char line [80];
    int n = 0, params [3];

    if (fgets (line, 80, file) == NULL) isValid = false;
    if (strlen (line) != 3 || strncmp (line, "P2", 2)) isValid = false;
    while (isValid && fgets (line, 80, file) != NULL)
    {
      if (strlen (line) <= 71)
      {
        if (line[0] == '#') continue;
        char *p = strtok (line, delimiter);
        while (isValid && p != NULL)
        {
          if (n < 3)
          {
            int a = atoi (p);
            if (a <= 0) {isValid = false;}
            else {params[n++] = a;}
          }
          else
          {
            if (n == 3)
            {
              if (params[2] != 255) {isValid = false;}
              else {
                pixels = createImage (params[0], params[1], 0);
                *width = params[0];
                *height = params[1];
              }
            }
            if (n-3 < *width * *height)
            {
              int x = (n-3) % *width;
              int y = (n-3) / *width;
              int value = atoi (p);
              pixels[y][x] = normalize(value);
              n++;
            }
            else {isValid = false;}
          }
          p = strtok (NULL, delimiter);
        }
      }
      else { isValid = false;}
    }
    fclose (file);
    if (n-3 != *width * *height) {isValid = false;}
    if (!isValid) freeImage (pixels, *width, *height);
  }
  return isValid ? pixels : NULL;
}

/* *** Bild in Datei speichern *** */

bool saveImage (const char *filename, int **pixels, unsigned int width, unsigned int height)
{
  FILE *file = fopen (filename, "wt");

  if (file != NULL && pixels != NULL)
  {
    fprintf (file, "P2\n");
    fprintf (file, "%d %d\n", width, height);
    fprintf (file, "%d\n", 255);
    for (int y = 0; y < height; y++)
    {
      for (int x = 0; x < width; x++)
      {
        fprintf (file, "%d\n", pixels[y][x]);
      }
    }
    fclose (file);
    return true;
  }
  return false;
}

教授还说我们应该在VSCode的任务中添加以下参数：

"args": [
"-g",
"-std=c99",
"-Wall",
"${file}",
"-o",
"${fileDirname}/${fileBasenameNoExtension}",
"-lm"
],

Answer 1

您的程序 a3.exe 需要一个参数，即文件名。要从命令行运行它，请输入

.\a3.exe YourFilename

将 YourFilename 替换为您要使用的实际文件名。

C 创建 PGM 图像的参数编号

C Argument number to create PGM images

c

arrays

image

pgm

visual-studio-code