bitmap image file manipulation using bitmap file structure in c - c

Question

I want to implement a simple command line based image editor. The program will
provide a text based menu, which provides several functions for user to manipulate a windows
bitmap (.bmp) image file. The menu will include load image, rotate image, mirror image, save image
and quit options. The load image option will be used to open and read pixel values from a given
bitmap file. This option will also print out the basic properties, such as dimensions and total size, of the given file. The rotate and mirror options will manipulate previously read pixel values. An image
must be loaded before applying these options. The save option will save the pixel values in the
memory to a bitmap file with a given filename.
Which approach do you recommend for me about this project and about bitmap file structure?
It would be very appreciated if you give me advice even about one particular topic for example load the file.

Answer 1

libbmp will make your program all but trivial to implement.

Answer 2

If you really want to use C then try the libbmp library http://code.google.com/p/libbmp/
However, I'd recommend using C#, then the task would be trivial with the System.Drawing namespace.

Answer 3

This function is used for loading a bmp file to memory.
you have to declare first a header file with bmp structure
BMP* load_BMP(char *filename);
BMP *bmp; // local integer for file loaded
FILE *in; // pointer for file opening
int rowsize;
int row, col, color, i;
unsigned char b;
in=fopen(filename,"rb"); // open binary file
if (in==NULL)
{
printf("Problem in opening file %s.\n",filename);
return NULL;
}
bmp=(BMP*) malloc(sizeof(BMP)); //memory allocation
if (bmp==NULL)
{
printf("Not enough memory to load the image.\n");
return NULL;
}
fread(bmp->BM,2,1,in);
if (bmp->BM[0]!='B' || bmp->BM[1]!='M')
{
printf("Bad BMP image file.\n");
free(bmp);
return NULL;
}
fread(&bmp->fileSize,4,1,in);
fread(&bmp->Reserved1,2,1,in);
fread(&bmp->Reserved2,2,1,in);
fread(&bmp->imageOffset,4,1,in);
fread(&bmp->imageHeaderSize,4,1,in);
fread(&bmp->imageWidth,4,1,in);
rowsize=4*((3*bmp->imageWidth+3)/4); //calculate rowsize because of padding
fread(&bmp->imageHeight,4,1,in);
fread(&bmp->colorPlanes,2,1,in);
fread(&bmp->compressionMethod,4,1,in);
fread(&bmp->imageSize,4,1,in);
fread(&bmp->hPPM,4,1,in);
fread(&bmp->vPPM,4,1,in);
fread(&bmp->paletteColors,4,1,in);
fread(&bmp->paletteImportantColors,4,1,in);
bmp->data=(unsigned char*) malloc(bmp->imageSize); //allocate memory for image data array
if (bmp->data==NULL)
{
printf("There is not enough memory to load the image\n");
free(bmp);
return NULL;
}
for(row=0;row<bmp->imageHeight;row++) //read picture data
{
for(col=0;col<bmp->imageWidth;col++)
for(color=0;color<=2;color++)
fread(&bmp->data[row*rowsize+3*col+color],
sizeof(unsigned char),1,in);
//read extra bytes for end of row padding
for(i=0;i<rowsize-3*bmp->imageWidth;i++)
fread(&b,1,1,in);
}
fclose(in);
return bmp;
}