/* Write a VIPS image to a JPEG compress struct.
*/
static int
write_vips( Write *write, int qfac, const char *profile )
{
IMAGE *in;
J_COLOR_SPACE space;
/* The image we'll be writing ... can change, see CMYK.
*/
in = write->in;
/* Should have been converted for save.
*/
g_assert( in->BandFmt == IM_BANDFMT_UCHAR );
g_assert( in->Coding == IM_CODING_NONE );
g_assert( in->Bands == 1 || in->Bands == 3 || in->Bands == 4 );
/* Check input image.
*/
if( im_pincheck( in ) )
return( -1 );
if( qfac < 0 || qfac > 100 ) {
im_error( "im_vips2jpeg",
"%s", _( "qfac should be in 0-100" ) );
return( -1 );
}
/* Set compression parameters.
*/
write->cinfo.image_width = in->Xsize;
write->cinfo.image_height = in->Ysize;
write->cinfo.input_components = in->Bands;
if( in->Bands == 4 && in->Type == IM_TYPE_CMYK ) {
space = JCS_CMYK;
/* IJG always sets an Adobe marker, so we should invert CMYK.
*/
if( !(write->inverted = im_open( "vips2jpeg_invert", "p" )) ||
im_invert( in, write->inverted ) )
return( -1 );
in = write->inverted;
}
else if( in->Bands == 3 )
space = JCS_RGB;
else if( in->Bands == 1 )
space = JCS_GRAYSCALE;
else
/* Use luminance compression for all channels.
*/
space = JCS_UNKNOWN;
write->cinfo.in_color_space = space;
/* Build VIPS output stuff now we know the image we'll be writing.
*/
if( !(write->row_pointer =
IM_ARRAY( NULL, write->in->Ysize, JSAMPROW )) )
return( -1 );
/* Rest to default.
*/
jpeg_set_defaults( &write->cinfo );
jpeg_set_quality( &write->cinfo, qfac, TRUE );
/* Build compress tables.
*/
jpeg_start_compress( &write->cinfo, TRUE );
/* Write any APP markers we need.
*/
if( write_exif( write ) )
return( -1 );
/* A profile supplied as an argument overrides an embedded profile.
* "none" means don't attach a profile.
*/
if( profile &&
strcmp( profile, "none" ) != 0 &&
write_profile_file( write, profile ) )
return( -1 );
if( !profile &&
im_header_get_typeof( in, IM_META_ICC_NAME ) &&
write_profile_meta( write ) )
return( -1 );
/* Write data. Note that the write function grabs the longjmp()!
*/
if( vips_sink_disc( write->in, write_jpeg_block, write ) )
return( -1 );
/* We have to reinstate the setjmp() before we jpeg_finish_compress().
*/
if( setjmp( write->eman.jmp ) )
return( -1 );
jpeg_finish_compress( &write->cinfo );
return( 0 );
}
/* Write a VIPS image to a JPEG compress struct.
*/
static int
write_vips( Write *write, int qfac, const char *profile,
gboolean optimize_coding, gboolean progressive, gboolean strip,
gboolean no_subsample, gboolean trellis_quant,
gboolean overshoot_deringing, gboolean optimize_scans, int quant_table )
{
VipsImage *in;
J_COLOR_SPACE space;
/* The image we'll be writing ... can change, see CMYK.
*/
in = write->in;
/* Should have been converted for save.
*/
g_assert( in->BandFmt == VIPS_FORMAT_UCHAR );
g_assert( in->Coding == VIPS_CODING_NONE );
g_assert( in->Bands == 1 ||
in->Bands == 3 ||
in->Bands == 4 );
/* Check input image.
*/
if( vips_image_pio_input( in ) )
return( -1 );
/* Set compression parameters.
*/
write->cinfo.image_width = in->Xsize;
write->cinfo.image_height = in->Ysize;
write->cinfo.input_components = in->Bands;
if( in->Bands == 4 &&
in->Type == VIPS_INTERPRETATION_CMYK ) {
space = JCS_CMYK;
/* IJG always sets an Adobe marker, so we should invert CMYK.
*/
if( vips_invert( in, &write->inverted, NULL ) )
return( -1 );
in = write->inverted;
}
else if( in->Bands == 3 )
space = JCS_RGB;
else if( in->Bands == 1 )
space = JCS_GRAYSCALE;
else
/* Use luminance compression for all channels.
*/
space = JCS_UNKNOWN;
write->cinfo.in_color_space = space;
/* Build VIPS output stuff now we know the image we'll be writing.
*/
if( !(write->row_pointer = VIPS_ARRAY( NULL, in->Ysize, JSAMPROW )) )
return( -1 );
#ifdef HAVE_JPEG_EXT_PARAMS
/* Reset compression profile to libjpeg defaults
*/
if( jpeg_c_int_param_supported( &write->cinfo, JINT_COMPRESS_PROFILE ) )
jpeg_c_set_int_param( &write->cinfo,
JINT_COMPRESS_PROFILE, JCP_FASTEST );
#endif
/* Reset to default.
*/
jpeg_set_defaults( &write->cinfo );
/* Compute optimal Huffman coding tables.
*/
write->cinfo.optimize_coding = optimize_coding;
#ifdef HAVE_JPEG_EXT_PARAMS
/* Apply trellis quantisation to each 8x8 block. Implies
* "optimize_coding".
*/
if( trellis_quant ) {
if( jpeg_c_bool_param_supported( &write->cinfo,
JBOOLEAN_TRELLIS_QUANT ) ) {
jpeg_c_set_bool_param( &write->cinfo,
JBOOLEAN_TRELLIS_QUANT, TRUE );
write->cinfo.optimize_coding = TRUE;
}
else
vips_warn( "vips2jpeg",
"%s", _( "trellis_quant unsupported" ) );
}
/* Apply overshooting to samples with extreme values e.g. 0 & 255
* for 8-bit.
*/
if( overshoot_deringing ) {
if( jpeg_c_bool_param_supported( &write->cinfo,
JBOOLEAN_OVERSHOOT_DERINGING ) )
jpeg_c_set_bool_param( &write->cinfo,
JBOOLEAN_OVERSHOOT_DERINGING, TRUE );
else
vips_warn( "vips2jpeg",
"%s", _( "overshoot_deringing unsupported" ) );
}
/* Split the spectrum of DCT coefficients into separate scans.
* Requires progressive output. Must be set before
* jpeg_simple_progression.
*/
if( optimize_scans ) {
if( progressive ) {
if( jpeg_c_bool_param_supported( &write->cinfo,
JBOOLEAN_OPTIMIZE_SCANS ) )
jpeg_c_set_bool_param( &write->cinfo,
JBOOLEAN_OPTIMIZE_SCANS, TRUE );
else
vips_warn( "vips2jpeg",
"%s", _( "Ignoring optimize_scans" ) );
}
else
vips_warn( "vips2jpeg", "%s",
_( "Ignoring optimize_scans for baseline" ) );
}
/* Use predefined quantization table.
*/
if( quant_table > 0 ) {
if( jpeg_c_int_param_supported( &write->cinfo,
JINT_BASE_QUANT_TBL_IDX ) )
jpeg_c_set_int_param( &write->cinfo,
JINT_BASE_QUANT_TBL_IDX, quant_table );
else
vips_warn( "vips2jpeg",
"%s", _( "Setting quant_table unsupported" ) );
}
#else
/* Using jpeglib.h without extension parameters, warn of ignored
* options.
*/
if( trellis_quant )
vips_warn( "vips2jpeg", "%s", _( "Ignoring trellis_quant" ) );
if( overshoot_deringing )
vips_warn( "vips2jpeg",
"%s", _( "Ignoring overshoot_deringing" ) );
if( optimize_scans )
vips_warn( "vips2jpeg", "%s", _( "Ignoring optimize_scans" ) );
if( quant_table > 0 )
vips_warn( "vips2jpeg", "%s", _( "Ignoring quant_table" ) );
#endif
/* Set compression quality. Must be called after setting params above.
*/
jpeg_set_quality( &write->cinfo, qfac, TRUE );
/* Enable progressive write.
*/
if( progressive )
jpeg_simple_progression( &write->cinfo );
/* Turn off chroma subsampling. Follow IM and do it automatically for
* high Q.
*/
if( no_subsample ||
qfac > 90 ) {
int i;
for( i = 0; i < in->Bands; i++ ) {
write->cinfo.comp_info[i].h_samp_factor = 1;
write->cinfo.comp_info[i].v_samp_factor = 1;
}
}
/* Don't write the APP0 JFIF headers if we are stripping.
*/
if( strip )
write->cinfo.write_JFIF_header = FALSE;
/* Build compress tables.
*/
jpeg_start_compress( &write->cinfo, TRUE );
/* Write any APP markers we need.
*/
if( !strip ) {
if( write_exif( write ) ||
write_blob( write,
VIPS_META_XMP_NAME, JPEG_APP0 + 1 ) ||
write_blob( write,
VIPS_META_IPCT_NAME, JPEG_APP0 + 13 ) )
return( -1 );
/* A profile supplied as an argument overrides an embedded
* profile. "none" means don't attach a profile.
*/
if( profile &&
strcmp( profile, "none" ) != 0 &&
write_profile_file( write, profile ) )
return( -1 );
if( !profile &&
vips_image_get_typeof( in, VIPS_META_ICC_NAME ) &&
write_profile_meta( write ) )
return( -1 );
}
/* Write data. Note that the write function grabs the longjmp()!
*/
if( vips_sink_disc( in, write_jpeg_block, write ) )
return( -1 );
/* We have to reinstate the setjmp() before we jpeg_finish_compress().
*/
if( setjmp( write->eman.jmp ) )
return( -1 );
jpeg_finish_compress( &write->cinfo );
return( 0 );
}