void jpeg_loader::read_image(const unsigned char * buffer, size_t len) {
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
// Setup decompression structure
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&cinfo);
my_set_source_mgr(&cinfo, buffer, len);
// read info from header.
int r = jpeg_read_header(&cinfo, TRUE);
jpeg_start_decompress(&cinfo);
// ..<snip>..
// .. decompress the JPEG here as usual
// ..<snip>..
height_ = cinfo.output_height;
width_ = cinfo.output_width;
output_components_ = cinfo.output_components;
if (output_components_ != 1 &&
output_components_ != 3 &&
output_components_ != 4)
{
jpeg_destroy_decompress(&cinfo);
std::ostringstream sout;
sout << "jpeg_loader: Unsupported number of colors (" << output_components_ << ") in buffer ";
throw image_load_error(sout.str());
}
std::vector<unsigned char*> rows;
rows.resize(height_);
// size the image buffer
data.resize(height_*width_*output_components_);
// setup pointers to each row
for (unsigned long i = 0; i < rows.size(); ++i)
rows[i] = &data[i*width_*output_components_];
// read the data into the buffer
while (cinfo.output_scanline < cinfo.output_height)
{
jpeg_read_scanlines(&cinfo, &rows[cinfo.output_scanline], 100);
}
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
}
void png_loader::read_image( const char* filename )
{
ld_.reset(new LibpngData);
if ( filename == NULL )
{
throw image_load_error("png_loader: invalid filename, it is NULL");
}
FILE *fp = fopen( filename, "rb" );
if ( !fp )
{
throw image_load_error(std::string("png_loader: unable to open file ") + filename);
}
png_byte sig[8];
if (fread( sig, 1, 8, fp ) != 8)
{
fclose( fp );
throw image_load_error(std::string("png_loader: error reading file ") + filename);
}
if ( png_sig_cmp( sig, 0, 8 ) != 0 )
{
fclose( fp );
throw image_load_error(std::string("png_loader: format error in file ") + filename);
}
ld_->png_ptr_ = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL );
if ( ld_->png_ptr_ == NULL )
{
fclose( fp );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
ld_->info_ptr_ = png_create_info_struct( ld_->png_ptr_ );
if ( ld_->info_ptr_ == NULL )
{
fclose( fp );
png_destroy_read_struct( &( ld_->png_ptr_ ), ( png_infopp )NULL, ( png_infopp )NULL );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
ld_->end_info_ = png_create_info_struct( ld_->png_ptr_ );
if ( ld_->end_info_ == NULL )
{
fclose( fp );
png_destroy_read_struct( &( ld_->png_ptr_ ), &( ld_->info_ptr_ ), ( png_infopp )NULL );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
png_init_io( ld_->png_ptr_, fp );
png_set_sig_bytes( ld_->png_ptr_, 8 );
// flags force one byte per channel output
png_read_png( ld_->png_ptr_, ld_->info_ptr_, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_PACKING, NULL );
height_ = png_get_image_height( ld_->png_ptr_, ld_->info_ptr_ );
width_ = png_get_image_width( ld_->png_ptr_, ld_->info_ptr_ );
bit_depth_ = png_get_bit_depth( ld_->png_ptr_, ld_->info_ptr_ );
color_type_ = png_get_color_type( ld_->png_ptr_, ld_-> info_ptr_ );
if (color_type_ != PNG_COLOR_TYPE_GRAY &&
color_type_ != PNG_COLOR_TYPE_RGB &&
color_type_ != PNG_COLOR_TYPE_RGB_ALPHA )
{
fclose( fp );
png_destroy_read_struct( &( ld_->png_ptr_ ), &( ld_->info_ptr_ ), &( ld_->end_info_ ) );
throw image_load_error(std::string("png_loader: unsupported color type in file ") + filename);
}
ld_->row_pointers_ = png_get_rows( ld_->png_ptr_, ld_->info_ptr_ );
// FIXME: the following call makes libpng crash. Why?
//png_read_end( ld_->png_ptr_, ld_->end_info_ );
fclose( fp );
if ( ld_->row_pointers_ == NULL )
{
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
}
void jpeg_loader::read_image( const char* filename )
{
if ( filename == NULL )
{
throw image_load_error("jpeg_loader: invalid filename, it is NULL");
}
FILE *fp = fopen( filename, "rb" );
if ( !fp )
{
throw image_load_error(std::string("jpeg_loader: unable to open file ") + filename);
}
jpeg_decompress_struct cinfo;
jpeg_loader_error_mgr jerr;
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = jpeg_loader_error_exit;
/* Establish the setjmp return context for my_error_exit to use. */
if (setjmp(jerr.setjmp_buffer))
{
/* If we get here, the JPEG code has signaled an error.
* We need to clean up the JPEG object, close the input file, and return.
*/
jpeg_destroy_decompress(&cinfo);
fclose(fp);
throw image_load_error(std::string("jpeg_loader: error while reading ") + filename);
}
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, fp);
jpeg_read_header(&cinfo, TRUE);
jpeg_start_decompress(&cinfo);
height_ = cinfo.output_height;
width_ = cinfo.output_width;
output_components_ = cinfo.output_components;
if (output_components_ != 1 &&
output_components_ != 3)
{
fclose( fp );
jpeg_destroy_decompress(&cinfo);
std::ostringstream sout;
sout << "jpeg_loader: Unsupported number of colors (" << output_components_ << ") in file " << filename;
throw image_load_error(sout.str());
}
std::vector<unsigned char*> rows;
rows.resize(height_);
// size the image buffer
data.resize(height_*width_*output_components_);
// setup pointers to each row
for (unsigned long i = 0; i < rows.size(); ++i)
rows[i] = &data[i*width_*output_components_];
// read the data into the buffer
while (cinfo.output_scanline < cinfo.output_height)
{
jpeg_read_scanlines(&cinfo, &rows[cinfo.output_scanline], 100);
}
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose( fp );
}
void png_loader::read_image( const char* filename )
{
ld_.reset(new LibpngData);
if ( filename == NULL )
{
throw image_load_error("png_loader: invalid filename, it is NULL");
}
FILE *fp = fopen( filename, "rb" );
if ( !fp )
{
throw image_load_error(std::string("png_loader: unable to open file ") + filename);
}
png_byte sig[8];
if (fread( sig, 1, 8, fp ) != 8)
{
fclose( fp );
throw image_load_error(std::string("png_loader: error reading file ") + filename);
}
if ( png_sig_cmp( sig, 0, 8 ) != 0 )
{
fclose( fp );
throw image_load_error(std::string("png_loader: format error in file ") + filename);
}
ld_->png_ptr_ = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, &png_loader_user_error_fn_silent, &png_loader_user_warning_fn_silent );
if ( ld_->png_ptr_ == NULL )
{
fclose( fp );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
ld_->info_ptr_ = png_create_info_struct( ld_->png_ptr_ );
if ( ld_->info_ptr_ == NULL )
{
fclose( fp );
png_destroy_read_struct( &( ld_->png_ptr_ ), ( png_infopp )NULL, ( png_infopp )NULL );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
ld_->end_info_ = png_create_info_struct( ld_->png_ptr_ );
if ( ld_->end_info_ == NULL )
{
fclose( fp );
png_destroy_read_struct( &( ld_->png_ptr_ ), &( ld_->info_ptr_ ), ( png_infopp )NULL );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
if (setjmp(png_jmpbuf(ld_->png_ptr_)))
{
// If we get here, we had a problem writing the file
fclose(fp);
png_destroy_read_struct( &( ld_->png_ptr_ ), &( ld_->info_ptr_ ), &( ld_->end_info_ ) );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
png_set_palette_to_rgb(ld_->png_ptr_);
png_init_io( ld_->png_ptr_, fp );
png_set_sig_bytes( ld_->png_ptr_, 8 );
// flags force one byte per channel output
byte_orderer bo;
int png_transforms = PNG_TRANSFORM_PACKING;
if (bo.host_is_little_endian())
png_transforms |= PNG_TRANSFORM_SWAP_ENDIAN;
png_read_png( ld_->png_ptr_, ld_->info_ptr_, png_transforms, NULL );
height_ = png_get_image_height( ld_->png_ptr_, ld_->info_ptr_ );
width_ = png_get_image_width( ld_->png_ptr_, ld_->info_ptr_ );
bit_depth_ = png_get_bit_depth( ld_->png_ptr_, ld_->info_ptr_ );
color_type_ = png_get_color_type( ld_->png_ptr_, ld_-> info_ptr_ );
if (color_type_ != PNG_COLOR_TYPE_GRAY &&
color_type_ != PNG_COLOR_TYPE_RGB &&
color_type_ != PNG_COLOR_TYPE_RGB_ALPHA )
{
fclose( fp );
png_destroy_read_struct( &( ld_->png_ptr_ ), &( ld_->info_ptr_ ), &( ld_->end_info_ ) );
throw image_load_error(std::string("png_loader: unsupported color type in file ") + filename);
}
if (bit_depth_ != 8 && bit_depth_ != 16)
{
fclose( fp );
png_destroy_read_struct( &( ld_->png_ptr_ ), &( ld_->info_ptr_ ), &( ld_->end_info_ ) );
throw image_load_error("png_loader: unsupported bit depth of " + cast_to_string(bit_depth_) + " in file " + std::string(filename));
}
ld_->row_pointers_ = png_get_rows( ld_->png_ptr_, ld_->info_ptr_ );
fclose( fp );
if ( ld_->row_pointers_ == NULL )
{
png_destroy_read_struct( &( ld_->png_ptr_ ), &( ld_->info_ptr_ ), &( ld_->end_info_ ) );
throw image_load_error(std::string("png_loader: parse error in file ") + filename);
}
}
