bool ImageLoaderJPG::LoadParams(Image &cImage, File &cFile, bool bBlockSmoothing, bool bFancyUpsampling)
{
jpeg_decompress_struct sInfo;
jpeg_error_mgr sError;
sInfo.err = jpeg_std_error(&sError);
sInfo.err->error_exit = ExitErrorHandle;
jpeg_create_decompress(&sInfo);
// Set the user given parameters
sInfo.do_block_smoothing = bBlockSmoothing;
sInfo.do_fancy_upsampling = bFancyUpsampling;
jpeg_read_init(&sInfo, &cFile);
jpeg_read_header(&sInfo, TRUE);
jpeg_start_decompress(&sInfo);
// Get the color format
EColorFormat nColorFormat;
switch (sInfo.num_components) {
case 1:
nColorFormat = ColorGrayscale;
break;
case 3:
nColorFormat = ColorRGB;
break;
case 4:
nColorFormat = ColorRGBA;
break;
default:
// Error: Unsupported color format
return false;
}
// Create image buffer
ImageBuffer *pImageBuffer = cImage.CreatePart()->CreateMipmap();
pImageBuffer->CreateImage(DataByte, nColorFormat, Vector3i(sInfo.output_width, sInfo.output_height, 1));
// Read in the data
uint8 *pCurrentData = pImageBuffer->GetData();
while (sInfo.output_scanline < sInfo.output_height) {
jpeg_read_scanlines(&sInfo, &pCurrentData, 1);
pCurrentData += pImageBuffer->GetBytesPerRow();
}
// Cleanup
jpeg_finish_decompress(&sInfo);
jpeg_destroy_decompress(&sInfo);
// Done
return true;
}
bool ImageLoaderJPG::SaveParams(const Image &cImage, File &cFile, uint32 nQuality)
{
// Get the image buffer
ImageBuffer *pImageBuffer = cImage.GetBuffer();
if (pImageBuffer && pImageBuffer->GetBytesPerRow()) {
// We only support 1 or 3 byte per pixel component
if (pImageBuffer->GetBytesPerPixelComponent() == 1 || pImageBuffer->GetBytesPerPixelComponent() == 3) {
jpeg_compress_struct sInfo;
jpeg_error_mgr sError;
sInfo.err = jpeg_std_error(&sError);
sInfo.err->error_exit = ExitErrorHandle;
jpeg_create_compress(&sInfo);
const int nComponents = pImageBuffer->GetComponentsPerPixel();
sInfo.in_color_space = (nComponents == 1)? JCS_GRAYSCALE : JCS_RGB;
jpeg_set_defaults(&sInfo);
sInfo.input_components = nComponents;
sInfo.num_components = (nComponents == 1) ? 1 : 3;
sInfo.image_width = pImageBuffer->GetSize().x;
sInfo.image_height = pImageBuffer->GetSize().y;
sInfo.data_precision = 8;
sInfo.input_gamma = 1.0;
// Set the user given parameter
jpeg_set_quality(&sInfo, nQuality, FALSE);
jpeg_write_init(&sInfo, &cFile);
jpeg_start_compress(&sInfo, TRUE);
// Is the input image RGBA? If so, we really need to throw away the alpha channel...
if (nComponents == 4) {
// Allocate memory for an converted output row
uint8 *pOutputRow = new uint8[sInfo.image_width*sInfo.num_components];
// Write the data
const uint8 *pCurrentImageData = pImageBuffer->GetData();
for (uint32 y=0; y<sInfo.image_height; y++) {
// Convert the current row
for (uint32 x=0; x<sInfo.image_width; x++) {
const uint8 *pnPixelIn = &pCurrentImageData[x*4];
uint8 *pnPixelOut = &pOutputRow[x*3];
pnPixelOut[0] = pnPixelIn[0];
pnPixelOut[1] = pnPixelIn[1];
pnPixelOut[2] = pnPixelIn[2];
}
// Write out the current row
jpeg_write_scanlines(&sInfo, &pOutputRow, 1);
// Next, please
pCurrentImageData += pImageBuffer->GetBytesPerRow();
}
// Free the allocated output row memory
delete [] pOutputRow;
} else {
// Write the data
uint8 *pCurrentImageData = pImageBuffer->GetData();
for (uint32 y=0; y<sInfo.image_height; y++) {
jpeg_write_scanlines(&sInfo, &pCurrentImageData, 1);
pCurrentImageData += pImageBuffer->GetBytesPerRow();
}
}
// Cleanup
jpeg_finish_compress(&sInfo);
jpeg_destroy_compress(&sInfo);
// Done
return true;
} else {
// Error: Unsupported number of bytes per pixel component
}
} else {
// Error: Failed to get image buffer
}
// Error!
return false;
}