Exemple #1
0
/* 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 );
}