gistfile1.c

BOOL bmp_open(char* file, IMAGE* image) {

	BITMAPFILEHEADER bmfh;
	BITMAPINFOHEADER bmih;
	unsigned int rowSize, i, totalPixels = 0;
	BYTE blue, green, red;

	/* note: "rb" means open for binary read */
	FILE* fp = fopen(file, "rb");

	if (fp == NULL) {
		/* failed to open file, return failure */
		perror("Could not open file");
		return FALSE;
	}

	/* todo: process file */
	fread(&bmfh, sizeof (bmfh), 1, fp);
	fread(&bmih, sizeof (bmih), 1, fp);

	image->Height = bmih.BiHeight;
	image->Width = bmih.BiWidth;

	// Starting address of the image data can be found in the file header
	fseek(fp, bmfh.BfOffBits, SEEK_SET);

	if (bmih.BiCompression == BI_RGB)
	{
		rowSize = ceil(bmih.BiBitCount * bmih.BiWidth / 32.0) * 4;

#ifdef DEBUG
		printf("Image compression: RGB%d\n", bmih.BiBitCount);
		printf("Bit offset: %d\n", bmfh.BfOffBits);
		printf("Row size: %d\n", rowSize);
#endif
		if (bmih.BiBitCount > 8) {
			for (i = 0; i < (bmih.BiWidth * bmih.BiHeight); i++) {
				fread(&blue, sizeof (BYTE), 1, fp);
				fread(&green, sizeof (BYTE), 1, fp);
				fread(&red, sizeof (BYTE), 1, fp);
				image->Pixels[i] = 0.11 * blue + 0.59 * green + 0.3 * red;
				if ((i + 1) % image->Width == 0) {
					fseek(fp, sizeof (BYTE) * ((image->Width) % 4), SEEK_CUR); // padding
				}
			}
		} else {
			// Assuming 8 bit
			for (i = 0; i < (bmih.BiWidth * bmih.BiHeight); i++) {
				fread(&blue, sizeof (BYTE), 1, fp);
				image->Pixels[i] = blue;
			}
		}

	} 
	else if ( bmih.BiCompression == BI_RLE8) 
	{
#ifdef DEBUG
		printf("Image compression: RLE8\n");
		printf("Bit offset: %d\n", bmfh.BfOffBits);
#endif
		/*if (!bmp_decompress(fp, image)) {
		printf("Failed to decompress RLE8 image");
		return EXIT_FAILURE;
		}*/
	}

#ifdef DEBUG
	printf("Image width:\t%d\nImage height:\t%d\n", image->Width, image->Height);
	printf("Pixels:\t%ld\n", sizeof(image->Pixels)/sizeof(BYTE));
	printf("\nImage upper left 3x3:\n\t%d\t%d\t%d\n\t%d\t%d\t%d\n\t%d\t%d\t%d\n\n",
		image->Pixels[0], image->Pixels[1], image->Pixels[2],
		image->Pixels[3], image->Pixels[4], image->Pixels[5],
		image->Pixels[6], image->Pixels[7], image->Pixels[8]);
#endif

	/* success */
	fclose(fp);
	return TRUE;
}

BOOL bmp_save(char* file, IMAGE* image, BOOL compress) {

	BITMAPFILEHEADER bmfh;
	BITMAPINFOHEADER bmih;
	unsigned int rowSize, i;
	COLORENTRY colorpalette[256];
	int compressOffset = 0;
	BYTE reserved = 0;

	/* note: "wb" means open for binary write */
	FILE* fp = fopen(file, "wb");

	if (fp == NULL) {
		/* failed to open file, return failure */
		perror("Could not open file");
		return FALSE;
	}

	/* todo: store image to fp */
	bmih.BiSize = sizeof (BITMAPINFOHEADER);
	bmih.BiWidth = image->Width;
	bmih.BiHeight = image->Height;
	bmih.BiPlanes = 1;
	bmih.BiBitCount = 8;
	bmih.BiCompression = BI_RGB;
	bmih.BiSizeImage = sizeof (BYTE) * image->Width * image->Height;
	bmih.BiXPelsPerMeter = 0;//2834;
	bmih.BiYPelsPerMeter = 0;//2834;
	bmih.BiClrUsed = 0;
	bmih.BiClrImportant = 0;
#ifdef DEBUG
	printf("Generating color palette..\n");
#endif

	bmfh.BfOffBits = sizeof (BITMAPFILEHEADER) + sizeof (BITMAPINFOHEADER);
	/*if (compress) {
		if (!(compressOffset = bmp_compress(image))) {
			printf("Failed to compress image with RLE8");
			return EXIT_FAILURE;
		}
		bmih.BiCompression = BI_RLE8;
		bmfh.BfOffBits += compressOffset;
	}
	else
	{*/
		bmfh.BfOffBits += sizeof(image->Pixels);
	//}

	bmfh.BfType = 0x4D42;
	bmfh.BfSize = bmfh.BfOffBits + bmih.BiSizeImage;
	bmfh.BfReserved1 = 0;
	bmfh.BfReserved2 = 0;

#ifdef DEBUG
	printf("Bit offset: %d\n", bmfh.BfOffBits);
#endif

	fwrite(&bmfh, sizeof (bmfh), 1, fp);
	/*fwrite(&bmfh.BfType, sizeof(bmfh.BfType), 1, fp);
	fwrite(&bmfh.BfSize, sizeof(bmfh.BfType), 1, fp);
	fwrite(&bmfh.BfReserved1, sizeof(bmfh.BfType), 1, fp);
	fwrite(&bmfh.BfReserved2, sizeof(bmfh.BfType), 1, fp);
	fwrite(&bmfh.BfOffBits, sizeof(bmfh.BfType), 1, fp);*/

	fwrite(&bmih, sizeof (bmih), 1, fp);
	/*fwrite(&bmih.BiSize, sizeof(bmih.BiSize), 1, fp);
	fwrite(&bmih.BiWidth, sizeof(bmih.BiWidth), 1, fp);
	fwrite(&bmih.BiHeight, sizeof(bmih.BiHeight), 1, fp);
	fwrite(&bmih.BiPlanes, sizeof(bmih.BiPlanes), 1, fp);
	fwrite(&bmih.BiBitCount, sizeof(bmih.BiBitCount), 1, fp);
	fwrite(&bmih.BiCompression, sizeof(bmih.BiCompression), 1, fp);
	fwrite(&bmih.BiSizeImage, sizeof(bmih.BiSizeImage), 1, fp);
	fwrite(&bmih.BiXPelsPerMeter, sizeof(bmih.BiXPelsPerMeter), 1, fp);
	fwrite(&bmih.BiYPelsPerMeter, sizeof(bmih.BiYPelsPerMeter), 1, fp);
	fwrite(&bmih.BiClrUsed, sizeof(bmih.BiClrUsed), 1, fp);
	fwrite(&bmih.BiClrImportant, sizeof(bmih.BiClrImportant), 1, fp);*/

	//fwrite(&colorpalette, sizeof (colorpalette), 1, fp);
	for(i = 0; i < 256; i++)
	{
		fwrite(&i, sizeof(BYTE), 3, fp);
		fwrite(&reserved, sizeof(BYTE), 1, fp);
	}

	rowSize = ceil(bmih.BiBitCount * bmih.BiWidth / 32.0) * 4;

#ifdef DEBUG
	printf("Row size: %d\n", rowSize);
	printf("\nImage upper left 3x3:\n\t%d\t%d\t%d\n\t%d\t%d\t%d\n\t%d\t%d\t%d\n\n",
		image->Pixels[0], image->Pixels[1], image->Pixels[2],
		image->Pixels[3], image->Pixels[4], image->Pixels[5],
		image->Pixels[6], image->Pixels[7], image->Pixels[8]);
#endif

	for (i = 0; i < (bmih.BiWidth * bmih.BiHeight); i++) {
		fwrite(&image->Pixels[i], sizeof (BYTE), 1, fp);
		if (( (i + 1) % image->Width == 0) ) {
			fwrite(" ", sizeof (BYTE), rowSize - image->Width, fp); // padding
		}
	}

	fclose(fp);
	return TRUE;
}