i want to store an JPEG image into a normal unsigned char array, i'd used ifstream to store it; however, when i checked if the array i'd stored is correct or not ( by rewrite it again to an JPEG image), the image that i rewrote by using the stored array couldn't show correctly, so i think the problem must come from the technique that i use to store the image into an array is not correct. I want an array which can be stored perfectly so that i can use it to rewrite back into a JPEG image again.I'd really appreciate if anyone can help me solve this problem!
int size = 921600;
unsigned char output[size];
int i = 0;
ifstream DataFile;
DataFile.open("abc.jpeg");
while(!DataFile.eof()){
DataFile >> output[i];
i++;
}
/* i try to rewrite the above array into a new image here */
FILE * image2;
image2 = fopen("def.jpeg", "w");
fwrite(output,1,921600, image2);
fclose(image2);
There are multiple problems in the shown code.
while(!DataFile.eof()){
This is always a bug. See the linked question for a detailed explanation.
DataFile >> output[i];
The formatted extraction operator, >>, by definition, skips over all white space characters and ignores them. Your jpg file surely has bytes 0x09, 0x20, and a few others, somewhere in it, and this automatically skips over and does not read them.
In order to do this correctly, you need to use read() and gcount() to read your binary file. Using gcount() correctly should also result in your code detecting the end-of-file condition properly.