用c语言读一张图片

我觉得写的很好，网上有一模一样的代码，感谢分享。

/*   *This program will open a image,and output to another file   *Author:hujian in nankai 2016/3/29*/#include  <cstdio>#include <iostream>using namespace std;#define   __FILENAME  "./img/in.jpg"  //this is the default image,if no input filename,the image will be usedint main(){    //the fp is the file stream of reading data    //the out is the file stream of writing to file(hex)    //the dst file is the file stream of dest image    //    FILE *fp, *out, *dstFile;    //this is the image size    //we will use fseek and ftell to get the size    //    long int size;    unsigned char ch, ch1, ch2;    //get the higt bites and low bites    //    unsigned char high, low;    //this is the image name buffer    //    char pic_name[30];    memset(pic_name, 0, sizeof(pic_name));    //we can input the file's name,and the program will open the image and do some    //oprtation,such as read data,write from image data..    ////#define INPUT#ifdef INPUT //if we want to input the filename ,just define the input.    printf("\nPlease input the image's name:");    cin >> pic_name;#else  //ok,you don't want to input    strcpy_s(pic_name,__FILENAME);#endif  INPUT    printf_s("The filename is:%s\n", pic_name);    //the follow lines will open the file    //    {        //open the src image for reading the image data        //        fopen_s(&fp, pic_name, "rb");        //open the text stream(write)        //        fopen_s(&out,"res.txt", "wb+");        //open the dest image file stream        //        fopen_s(&dstFile,"./img/res.jpg", "wb+");        //ok,check the file stream        //        {            if (!fp || !out || !dstFile){                printf_s("Can not open the file you input,check the filename and re-try\n");                //exit(EXIT_FAILURE);            }        }    }//end of open file,now we get the file stream done.    //we want to get the size of the image,we just use the fseek and ftell get the size    //    fseek(fp, 0, SEEK_END);    size = ftell(fp);    //printf the size    printf("get the size is: %d\n", size);    //rewind means jump to start of the file    //    rewind(fp);    //traversal the image data    //    long int i;    for (i = 0; i<size; i++)    {        ch = fgetc(fp);        high = ch >> 4;        low = ch & 0x0f;        if (high < 10)            high += '0';        else            high += 55;        if (low < 10)            low += '0';        else            low += 55;        //write to file stream out        //        fputc(high, out);        fputc(low, out);        fputc(' ', out);        //16 one line        //        if (i % 16 == 0)            fprintf(out, "\r\n");    }    //jump to start of the image file    //    rewind(fp);    bool FormatRight = false;    for (i = 0; i<size; i++)    {        ch1 = fgetc(fp);        if (ch1 == 0xff)        {            ch2 = fgetc(fp);            if (ch2 == 0xd8)            {                fputc(ch1, dstFile);                fputc(ch2, dstFile);                FormatRight = true;                break;            }        }    }    if (FormatRight)    {        for (; i<size; i++)        {            ch1 = fgetc(fp);            fputc(ch1, dstFile);            if (ch1 == 0xff)            {                ch2 = fgetc(fp);                if (ch2 == 0xd9)                    break;                else                    fputc(ch2, dstFile);            }        }    }    //close the image file stream    //    fclose(fp);    fclose(out);    fclose(dstFile);    printf_s("--operation done--\n");    return 0;}