int R2Image::
ReadBMP(const char *filename)
{
// Open file
FILE *fp = fopen(filename, "rb");
if (!fp) {
fprintf(stderr, "Unable to open image file: %s\n", filename);
return 0;
}
/* Read file header */
BITMAPFILEHEADER bmfh;
bmfh.bfType = WordReadLE(fp);
bmfh.bfSize = DWordReadLE(fp);
bmfh.bfReserved1 = WordReadLE(fp);
bmfh.bfReserved2 = WordReadLE(fp);
bmfh.bfOffBits = DWordReadLE(fp);
/* Check file header */
assert(bmfh.bfType == BMP_BF_TYPE);
/* ignore bmfh.bfSize */
/* ignore bmfh.bfReserved1 */
/* ignore bmfh.bfReserved2 */
assert(bmfh.bfOffBits == BMP_BF_OFF_BITS);
/* Read info header */
BITMAPINFOHEADER bmih;
bmih.biSize = DWordReadLE(fp);
bmih.biWidth = LongReadLE(fp);
bmih.biHeight = LongReadLE(fp);
bmih.biPlanes = WordReadLE(fp);
bmih.biBitCount = WordReadLE(fp);
bmih.biCompression = DWordReadLE(fp);
bmih.biSizeImage = DWordReadLE(fp);
bmih.biXPelsPerMeter = LongReadLE(fp);
bmih.biYPelsPerMeter = LongReadLE(fp);
bmih.biClrUsed = DWordReadLE(fp);
bmih.biClrImportant = DWordReadLE(fp);
// Check info header
assert(bmih.biSize == BMP_BI_SIZE);
assert(bmih.biWidth > 0);
assert(bmih.biHeight > 0);
assert(bmih.biPlanes == 1);
assert(bmih.biBitCount == 24); /* RGB */
assert(bmih.biCompression == BI_RGB); /* RGB */
int lineLength = bmih.biWidth * 3; /* RGB */
if ((lineLength % 4) != 0) lineLength = (lineLength / 4 + 1) * 4;
assert(bmih.biSizeImage == (unsigned int) lineLength * (unsigned int) bmih.biHeight);
// Assign width, height, and number of pixels
width = bmih.biWidth;
height = bmih.biHeight;
npixels = width * height;
// Allocate unsigned char buffer for reading pixels
int rowsize = 3 * width;
if ((rowsize % 4) != 0) rowsize = (rowsize / 4 + 1) * 4;
int nbytes = bmih.biSizeImage;
unsigned char *buffer = new unsigned char [nbytes];
if (!buffer) {
fprintf(stderr, "Unable to allocate temporary memory for BMP file");
fclose(fp);
return 0;
}
// Read buffer
fseek(fp, (long) bmfh.bfOffBits, SEEK_SET);
if (fread(buffer, 1, bmih.biSizeImage, fp) != bmih.biSizeImage) {
fprintf(stderr, "Error while reading BMP file %s", filename);
return 0;
}
// Close file
fclose(fp);
// Allocate pixels for image
pixels = new R2Pixel [ width * height ];
if (!pixels) {
fprintf(stderr, "Unable to allocate memory for BMP file");
fclose(fp);
return 0;
}
// Assign pixels
for (int j = 0; j < height; j++) {
unsigned char *p = &buffer[j * rowsize];
for (int i = 0; i < width; i++) {
double b = (double) *(p++) / 255;
double g = (double) *(p++) / 255;
double r = (double) *(p++) / 255;
R2Pixel pixel(r, g, b, 1);
SetPixel(i, j, pixel);
}
}
// Free unsigned char buffer for reading pixels
delete [] buffer;
// Return success
return 1;
}
int R2Image::
ReadBMP(const char *filename)
{
// Open file
FILE *fp = fopen(filename, "rb");
if (!fp) {
fprintf(stderr, "Unable to open image file: %s", filename);
return 0;
}
/* Read file header */
BITMAPFILEHEADER bmfh;
bmfh.bfType = WordReadLE(fp);
bmfh.bfSize = DWordReadLE(fp);
bmfh.bfReserved1 = WordReadLE(fp);
bmfh.bfReserved2 = WordReadLE(fp);
bmfh.bfOffBits = DWordReadLE(fp);
/* Check file header */
assert(bmfh.bfType == BMP_BF_TYPE);
/* ignore bmfh.bfSize */
/* ignore bmfh.bfReserved1 */
/* ignore bmfh.bfReserved2 */
assert(bmfh.bfOffBits == BMP_BF_OFF_BITS);
/* Read info header */
BITMAPINFOHEADER bmih;
bmih.biSize = DWordReadLE(fp);
bmih.biWidth = LongReadLE(fp);
bmih.biHeight = LongReadLE(fp);
bmih.biPlanes = WordReadLE(fp);
bmih.biBitCount = WordReadLE(fp);
bmih.biCompression = DWordReadLE(fp);
bmih.biSizeImage = DWordReadLE(fp);
bmih.biXPelsPerMeter = LongReadLE(fp);
bmih.biYPelsPerMeter = LongReadLE(fp);
bmih.biClrUsed = DWordReadLE(fp);
bmih.biClrImportant = DWordReadLE(fp);
// Check info header
assert(bmih.biSize == BMP_BI_SIZE);
assert(bmih.biWidth > 0);
assert(bmih.biHeight > 0);
assert(bmih.biPlanes == 1);
assert(bmih.biBitCount == 24); /* RGB */
assert(bmih.biCompression == BI_RGB); /* RGB */
int lineLength = bmih.biWidth * 3; /* RGB */
if ((lineLength % 4) != 0) lineLength = (lineLength / 4 + 1) * 4;
assert(bmih.biSizeImage == (unsigned int) lineLength * (unsigned int) bmih.biHeight);
// Assign width, height, and ncomponents
width = bmih.biWidth;
height = bmih.biHeight;
ncomponents = 3;
rowsize = ncomponents * width;
if ((rowsize % 4) != 0) rowsize = (rowsize / 4 + 1) * 4;
// Allocate pixels
int nbytes = bmih.biSizeImage;
pixels = new unsigned char [nbytes];
if (!pixels) {
fprintf(stderr, "Unable to allocate memory for BMP file");
fclose(fp);
return 0;
}
// Read pixels
fseek(fp, (long) bmfh.bfOffBits, SEEK_SET);
if (fread(pixels, 1, bmih.biSizeImage, fp) != bmih.biSizeImage) {
fprintf(stderr, "Error while reading BMP file %s", filename);
return 0;
}
// Swap blue and red in each pixel
for (int j = 0; j < height; j++) {
unsigned char *p = &pixels[j * rowsize];
for (int i = 0; i < width; i++) {
unsigned char c = *p;
*(p) = *(p+2);
*(p+2) = c;
p += 3;
}
}
// Close file
fclose(fp);
// Return success
return 1;
}
