/* saveTargaColorMatrix()
* ----------------------
* Save the specified ColorMatrix as the specified targa file
* @param targaFilename - name of the targa file to save as (including .tga)
* @return - true on successful save, false on failure
*/
bool ImageProcessing::saveTargaColorMatrix(const string& targaFilename,
const ColorMatrix& source)
{
// Try to load a blank targa for the output
TargaImage* dest = TargaImage::blankImage(source.cols(), source.rows());
if( dest == nullptr ) {
cout << "Error: unable to create blank image for output." << endl;
return false;
}
// Setup constants for the output image
const unsigned int rows = dest->height();
const unsigned int cols = dest->width();
unsigned char* pixels = dest->pixels();
// Write the source ColorMatrix to the dest TargaImage
for(unsigned int row = 0, i = 0; row < rows; ++row)
for(unsigned int col = 0; col < cols; ++col, ++i)
{
const Color color(source(row,col));
pixels[i*4 + 0] = color.r();
pixels[i*4 + 1] = color.g();
pixels[i*4 + 2] = color.b();
pixels[i*4 + 3] = color.a();
}
// Save the new dest TargaImage
bool success = true;
if( dest->write(targaFilename.c_str()) != 1 ) {
cout << "Error: unable to save " << targaFilename
<< ", " << tga_error_string(tga_get_last_error())
<< endl;
success = false;
}
// Cleanup the new TargaImage
delete dest;
return success;
}
/* loadTargaColorMatrix()
* ----------------------
* Load the specified targa file into a ColorMatrix object
* @param targaFilename - name of the targa file to open (including .tga)
* @return - pixel data from the targa file in a ColorMatrix object
*/
ColorMatrix ImageProcessing::loadTargaColorMatrix(const string& targaFilename)
{
// Try to load the targa image
TargaImage* image = TargaImage::readImage(targaFilename.c_str());
if( image == nullptr ) {
stringstream ss;
ss << "Error: unable to open " << targaFilename << endl;
throw FailedToLoad(ss.str());
}
// Setup constants from the input image
const unsigned int rows = image->height();
const unsigned int cols = image->width();
const unsigned char* pixels = image->pixels();
if( pixels == nullptr ) {
stringstream ss;
ss << "Error: invalid pixel data in " << targaFilename << endl;
throw BadPixelData(ss.str());
}
// Generate the color matrix based on the image pixels
ColorMatrix colors(rows, cols);
for(unsigned int row = 0, i = 0; row < rows; ++row)
for(unsigned int col = 0; col < cols; ++col, ++i)
{
colors(row,col) = Color(pixels[i*4 + 0], // red
pixels[i*4 + 1], // green
pixels[i*4 + 2], // blue
pixels[i*4 + 3]); // alpha
}
// Cleanup the TargaImage
delete image;
return colors;
}
