Stegano

//Read a binary file //Bitmap file header contain the information about == type == , == size == , == layout == --->14 bytes //Bitmap information header contain the information about == dim == , == type of compresion==, ==coulor format== --->40 bytes #include<stdio.h> #include<stdlib.h> #include <string.h> int width, height, image_size, text_size, buff_bit_size, my_text[100]; unsigned char Mat[100000][3]; char TextToBinary[100 * 8]; void Read_BMP_FILE() { //Deschiderea fisierului image.bmp si citirea FILE* image = fopen("image.bmp", "rb"); fseek(image, 18, SEEK_SET); //Mutam cursorul de la inceputul fisierului SEEK_SET peste 18 octeti pozitie citind astfel dim fread(&width, sizeof(int), 1, image); fread(&height, sizeof(int), 1, image); //printf("%i x %i", width, height); fseek(image, 54, SEEK_SET); image_size = width * height; //width * height * 3 bytes for pixel //BGR->RGB for (int i = 0; i < image_size; ++i) { Mat[i][2] = getc(image); Mat[i][1] = getc(image); Mat[i][0] = getc(image); } fclose(image); } void Read_Message_Text() { FILE* text = fopen("text.txt", "r"); fread(my_text, sizeof(char), 100, text); text_size = strlen(my_text); fclose(text); } void ConvertTextToBinary(char *str) { char binars[9]; int cnt = 0; char output[9]; while (*str) { itoa(*str, output, 2); for (int i = 0; i < 7; ++i) TextToBinary[buff_bit_size++] = output[i]; //puts(output); ++str; } } void ComputeEachPixel() { for (int i = 0, j = 0; i < buff_bit_size; i += 3, ++j) { if (TextToBinary[i] == '1') { if (Mat[j][0] % 2 == 0) Mat[j][0] += 1; } else { if (Mat[j][0] % 2) Mat[j][0] -= 1; } if (TextToBinary[i + 1] == '1') { if (Mat[j][1] % 2 == 0) Mat[j][1] += 1; } else { if (Mat[j][1] % 2) Mat[j][1] -= 1; } if (TextToBinary[i + 2] == '1') { if (Mat[j][2] % 2 == 0) Mat[j][2] += 1; } else { if (Mat[j][2] % 2) Mat[j][2] -= 1; } } } int main() { //Codul maxim a unui caracter este 'Z' = 90 <= 2^7 ===> maxim 7 biti pentru fiecare caracter Read_BMP_FILE(); Read_Message_Text(); ConvertTextToBinary(my_text); ComputeEachPixel(); getch(); return 0; }