Exemple #1
0
/* Call im_extract_band via arg vector.
 */
static int
extract_band_vec( im_object *argv )
{
	int chsel = *((int *) argv[2]);

	return( im_extract_band( argv[0], argv[1], chsel ) );
}
/* Two images overlap in an area ... make a mask the size of the area, which
 * has 255 for every pixel where both images are non-zero.
 */
static int
make_overlap_mask( IMAGE *ref, IMAGE *sec, IMAGE *mask, 
	Rect *rarea, Rect *sarea )
{
	IMAGE *t[6];

	if( im_open_local_array( mask, t, 6, "mytemps", "p" ) ||
		extract_rect( ref, t[0], rarea ) ||
		extract_rect( sec, t[1], sarea ) ||
		im_extract_band( t[0], t[2], 0 ) ||
		im_extract_band( t[1], t[3], 0 ) ||
		im_notequalconst( t[2], t[4], 0.0 ) || 
		im_notequalconst( t[3], t[5], 0.0 ) || 
		im_andimage( t[4], t[5], mask ) ) 
		return( -1 );

	return( 0 );
}
Exemple #3
0
/**
 * im_tone_map:
 * @in: input image
 * @out: output image
 * @lut: look-up table
 *
 * Map the first channel of @in through @lut. If @in is IM_CODING_LABQ, unpack
 * to LABS, map L and then repack.
 *
 * @in should be a LABS or LABQ image for this to work
 * sensibly.
 *
 * See also: im_maplut().
 *
 * Returns: 0 on success, -1 on error
 */
int
im_tone_map( IMAGE *in, IMAGE *out, IMAGE *lut )
{
    IMAGE *t[8];

    if( im_check_hist( "im_tone_map", lut ) ||
            im_open_local_array( out, t, 8, "im_tone_map", "p" ) )
        return( -1 );

    /* If in is IM_CODING_LABQ, unpack.
     */
    if( in->Coding == IM_CODING_LABQ ) {
        if( im_LabQ2LabS( in, t[0] ) )
            return( -1 );
    }
    else
        t[0] = in;

    /* Split into bands.
     */
    if( im_extract_band( t[0], t[1], 0 ) )
        return( -1 );
    if( t[0]->Bands > 1 ) {
        if( im_extract_bands( t[0], t[2], 1, t[0]->Bands - 1 ) )
            return( -1 );
    }

    /* Map L.
     */
    if( im_maplut( t[1], t[3], lut ) )
        return( -1 );

    /* Recombine bands.
     */
    if( t[0]->Bands > 1 ) {
        if( im_bandjoin( t[3], t[2], t[4] ) )
            return( -1 );
    }
    else
        t[4] = t[3];

    /* If input was LabQ, repack.
     */
    if( in->Coding == IM_CODING_LABQ ) {
        if( im_LabS2LabQ( t[4], t[5] ) )
            return( -1 );
    }
    else
        t[5] = t[4];

    return( im_copy( t[4], out ) );
}
Exemple #4
0
/**
 * im_tone_analyse:
 * @in: input image
 * @out: output image
 * @Ps: shadow point (eg. 0.2)
 * @Pm: mid-tone point (eg. 0.5)
 * @Ph: highlight point (eg. 0.8)
 * @S: shadow adjustment (+/- 30)
 * @M: mid-tone adjustment (+/- 30)
 * @H: highlight adjustment (+/- 30)
 *
 * As im_tone_build(), but analyse the histogram of @in and use it to
 * pick the 0.1% and 99.9% points for @Lb and @Lw.
 *
 * See also: im_tone_build().
 *
 * Returns: 0 on success, -1 on error
 */
int
im_tone_analyse(
    IMAGE *in,
    IMAGE *out,
    double Ps, double Pm, double Ph,
    double S, double M, double H )
{
    IMAGE *t[4];
    int low, high;
    double Lb, Lw;

    if( im_open_local_array( out, t, 4, "im_tone_map", "p" ) )
        return( -1 );

    /* If in is IM_CODING_LABQ, unpack.
     */
    if( in->Coding == IM_CODING_LABQ ) {
        if( im_LabQ2LabS( in, t[0] ) )
            return( -1 );
    }
    else
        t[0] = in;

    /* Should now be 3-band short.
     */
    if( im_check_uncoded( "im_tone_analyse", t[0] ) ||
            im_check_bands( "im_tone_analyse", t[0], 3 ) ||
            im_check_format( "im_tone_analyse", t[0], IM_BANDFMT_SHORT ) )
        return( -1 );

    if( im_extract_band( t[0], t[1], 0 ) ||
            im_clip2fmt( t[1], t[2], IM_BANDFMT_USHORT ) ||
            im_histgr( t[2], t[3], -1 ) )
        return( -1 );

    if( im_mpercent_hist( t[3], 0.1 / 100.0, &high ) ||
            im_mpercent_hist( t[3], 99.9 / 100.0, &low ) )
        return( -1 );

    Lb = 100 * low / 32768;
    Lw = 100 * high / 32768;

    im_diag( "im_tone_analyse", "set Lb = %g, Lw = %g", Lb, Lw );

    return( im_tone_build( out, Lb, Lw, Ps, Pm, Ph, S, M, H ) );
}
Exemple #5
0
/* Transform an n-band image with a 1-band processing function.
 */
int 
im__fftproc( IMAGE *dummy, IMAGE *in, IMAGE *out, im__fftproc_fn fn )
{
	if( im_pincheck( in ) || im_outcheck( out ) )
                return( -1 );
	
	if( in->Bands == 1 ) {
		if( fn( dummy, in, out ) )
			return( -1 );
	}
	else {
		IMAGE *acc;
		int b;

		for( acc = NULL, b = 0; b < in->Bands; b++ ) {
			IMAGE *t1 = im_open_local( dummy, 
				"fwfftn:1", "p" );
			IMAGE *t2 = im_open_local( dummy, 
				"fwfftn:2", "p" );

			if( !t1 || !t2 || 
				im_extract_band( in, t1, b ) ||
				fn( dummy, t1, t2 ) )
				return( -1 );
			
			if( !acc )
				acc = t2;
			else {
				IMAGE *t3 = im_open_local( dummy, 
					"fwfftn:3", "p" );

				if( !t3 || im_bandjoin( acc, t2, t3 ) )
					return( -1 );

				acc = t3;
			}
		}

		if( im_copy( acc, out ) )
			return( -1 );
	}

	return( 0 );
}
Exemple #6
0
/**
 * im_correl:
 * @ref: reference image
 * @sec: secondary image
 * @xref: position in reference image
 * @yref: position in reference image
 * @xsec: position in secondary image
 * @ysec: position in secondary image
 * @hwindowsize: half window size
 * @hsearchsize: half search size 
 * @correlation: return detected correlation
 * @x: return found position
 * @y: return found position
 *
 * This operation finds the position of @sec within @ref. 
 *
 * The area around
 * (@xsec, @ysec) is searched for the best match to the area around (@xref,
 * @yref). It  searches an area of size @hsearchsize for a
 * match of size @hwindowsize.  The position of the best match is
 * returned, together with the correlation at that point.
 *
 * Only  the  first  band  of each image is correlated. @ref and @sec may be
 * very large --- the function  extracts  and  generates  just  the
 * parts needed.  Correlation is done with im_spcor(); the position of
 * the maximum is found with im_maxpos().
 * 
 * See also: im_match_linear(), im_match_linear_search(), im_lrmosaic().
 *
 * Returns: 0 on success, -1 on error
 */
int 
im_correl( IMAGE *ref, IMAGE *sec, 
	int xref, int yref, int xsec, int ysec,
	int hwindowsize, int hsearchsize,
	double *correlation, int *x, int *y )
{
	IMAGE *surface = im_open( "surface", "t" );
	IMAGE *t1, *t2, *t3, *t4;

	Rect refr, secr;
	Rect winr, srhr;
	Rect wincr, srhcr;

	if( !surface || 
		!(t1 = im_open_local( surface, "correlate:1", "p" )) ||
		!(t2 = im_open_local( surface, "correlate:1", "p" )) ||
		!(t3 = im_open_local( surface, "correlate:1", "p" )) ||
		!(t4 = im_open_local( surface, "correlate:1", "p" )) )
		return( -1 );
	
	/* Find position of window and search area, and clip against image
	 * size.
	 */
	refr.left = 0;
	refr.top = 0;
	refr.width = ref->Xsize;
	refr.height = ref->Ysize;
	winr.left = xref - hwindowsize;
	winr.top = yref - hwindowsize;
	winr.width = hwindowsize*2 + 1;
	winr.height = hwindowsize*2 + 1;
	im_rect_intersectrect( &refr, &winr, &wincr );

	secr.left = 0;
	secr.top = 0;
	secr.width = sec->Xsize;
	secr.height = sec->Ysize;
	srhr.left = xsec - hsearchsize;
	srhr.top = ysec - hsearchsize;
	srhr.width = hsearchsize*2 + 1;
	srhr.height = hsearchsize*2 + 1;
	im_rect_intersectrect( &secr, &srhr, &srhcr );

	/* Extract window and search area.
	 */
	if( im_extract_area( ref, t1, 
			wincr.left, wincr.top, wincr.width, wincr.height ) ||
		im_extract_area( sec, t2, 
			srhcr.left, srhcr.top, srhcr.width, srhcr.height ) ) {
		im_close( surface );
		return( -1 );
	}

	/* Make sure we have just one band. From im_*mosaic() we will, but
	 * from im_match_linear_search() etc. we may not.
	 */
	if( t1->Bands != 1 ) {
		if( im_extract_band( t1, t3, 0 ) ) {
			im_close( surface );
			return( -1 );
		}
		t1 = t3;
	}
	if( t2->Bands != 1 ) {
		if( im_extract_band( t2, t4, 0 ) ) {
			im_close( surface );
			return( -1 );
		}
		t2 = t4;
	}

	/* Search!
	 */
	if( im_spcor( t2, t1, surface ) ) {
		im_close( surface );
		return( -1 );
	}

	/* Find maximum of correlation surface.
	 */
	if( im_maxpos( surface, x, y, correlation ) ) {
		im_close( surface );
		return( -1 );
	}
	im_close( surface );

	/* Translate back to position within sec.
	 */
	*x += srhcr.left;
	*y += srhcr.top;

	return( 0 );
}
/* The main part of the benchmark ... transform labq to labq. Chain several of
 * these together to get a CPU-bound operation.
 */
static int
benchmark( IMAGE *in, IMAGE *out )
{
	IMAGE *t[18];
	double one[3] = { 1.0, 1.0, 1.0 };
	double zero[3] = { 0.0, 0.0, 0.0 };
	double darken[3] = { 1.0 / 1.18, 1.0, 1.0 };
	double whitepoint[3] = { 1.06, 1.0, 1.01 };
	double shadow[3] = { -2, 0, 0 };
	double white[3] = { 100, 0, 0 };
	DOUBLEMASK *d652d50 = im_create_dmaskv( "d652d50", 3, 3,
		1.13529, -0.0604663, -0.0606321,
		0.0975399, 0.935024, -0.0256156,
		-0.0336428, 0.0414702, 0.994135 );

	im_add_close_callback( out, 
		(im_callback_fn) im_free_dmask, d652d50, NULL );

	return( 	
		/* Set of descriptors for this operation.
		 */
		im_open_local_array( out, t, 18, "im_benchmark", "p" ) ||

		/* Unpack to float.
		 */
		im_LabQ2Lab( in, t[0] ) ||

		/* Crop 100 pixels off all edges.
		 */
		im_extract_area( t[0], t[1], 
			100, 100, t[0]->Xsize - 200, t[0]->Ysize - 200 ) ||

		/* Shrink by 10%, bilinear interp.
		 */
		im_affinei_all( t[1], t[2],
			vips_interpolate_bilinear_static(),
			0.9, 0, 0, 0.9, 
			0, 0 ) || 

		/* Find L ~= 100 areas (white surround).
		 */
		im_extract_band( t[2], t[3], 0 ) ||
		im_moreconst( t[3], t[4], 99 ) ||

		/* Adjust white point and shadows.
		 */
		im_lintra_vec( 3, darken, t[2], zero, t[5] ) ||
		im_Lab2XYZ( t[5], t[6] ) ||
		im_recomb( t[6], t[7], d652d50 ) ||
		im_lintra_vec( 3, whitepoint, t[7], zero, t[8] ) ||
		im_lintra( 1.5, t[8], 0.0, t[9] ) ||
		im_XYZ2Lab( t[9], t[10] ) ||
		im_lintra_vec( 3, one, t[10], shadow, t[11] ) ||

		/* Make a solid white image.
		 */
		im_black( t[12], t[4]->Xsize, t[4]->Ysize, 3 ) ||
		im_lintra_vec( 3, zero, t[12], white, t[13] ) ||

		/* Reattach border.
		 */
		im_ifthenelse( t[4], t[13], t[11], t[14] ) ||

		/* Sharpen.
		 */
		im_Lab2LabQ( t[14], t[15] ) ||
		im_sharpen( t[15], out, 11, 2.5, 40, 20, 0.5, 1.5 ) 
	);
}
Exemple #8
0
/* Convert to a saveable format. 
 *
 * im__saveable_t gives the general type of image
 * we make: vanilla 1/3 bands (eg. PPM), with an optional alpha (eg. PNG), or
 * with CMYK as an option (eg. JPEG). 
 *
 * format_table[] says how to convert each input format. 
 *
 * Need to im_close() the result IMAGE.
 */
IMAGE *
im__convert_saveable( IMAGE *in, 
	im__saveable_t saveable, int format_table[10] ) 
{
	IMAGE *out;

	if( !(out = im_open( "convert-for-save", "p" )) )
		return( NULL );

	/* If this is an IM_CODING_LABQ, we can go straight to RGB.
	 */
	if( in->Coding == IM_CODING_LABQ ) {
		IMAGE *t = im_open_local( out, "conv:1", "p" );
		static void *table = NULL;

		/* Make sure fast LabQ2disp tables are built. 7 is sRGB.
		 */
		if( !table ) 
			table = im_LabQ2disp_build_table( NULL, 
				im_col_displays( 7 ) );

		if( !t || im_LabQ2disp_table( in, t, table ) ) {
			im_close( out );
			return( NULL );
		}

		in = t;
	}

	/* If this is an IM_CODING_RAD, we go to float RGB or XYZ. We should
	 * probably un-gamma-correct the RGB :(
	 */
	if( in->Coding == IM_CODING_RAD ) {
		IMAGE *t;

		if( !(t = im_open_local( out, "conv:1", "p" )) || 
			im_rad2float( in, t ) ) {
			im_close( out );
			return( NULL );
		}

		in = t;
	}

	/* Get the bands right. 
	 */
	if( in->Coding == IM_CODING_NONE ) {
		if( in->Bands == 2 && saveable != IM__RGBA ) {
			IMAGE *t = im_open_local( out, "conv:1", "p" );

			if( !t || im_extract_band( in, t, 0 ) ) {
				im_close( out );
				return( NULL );
			}

			in = t;
		}
		else if( in->Bands > 3 && saveable == IM__RGB ) {
			IMAGE *t = im_open_local( out, "conv:1", "p" );

			if( !t ||
				im_extract_bands( in, t, 0, 3 ) ) {
				im_close( out );
				return( NULL );
			}

			in = t;
		}
		else if( in->Bands > 4 && 
			(saveable == IM__RGB_CMYK || saveable == IM__RGBA) ) {
			IMAGE *t = im_open_local( out, "conv:1", "p" );

			if( !t ||
				im_extract_bands( in, t, 0, 4 ) ) {
				im_close( out );
				return( NULL );
			}

			in = t;
		}

		/* Else we have saveable IM__ANY and we don't chop bands down.
		 */
	}

	/* Interpret the Type field for colorimetric images.
	 */
	if( in->Bands == 3 && in->BandFmt == IM_BANDFMT_SHORT && 
		in->Type == IM_TYPE_LABS ) {
		IMAGE *t = im_open_local( out, "conv:1", "p" );

		if( !t || im_LabS2LabQ( in, t ) ) {
			im_close( out );
			return( NULL );
		}

		in = t;
	}

	if( in->Coding == IM_CODING_LABQ ) {
		IMAGE *t = im_open_local( out, "conv:1", "p" );

		if( !t || im_LabQ2Lab( in, t ) ) {
			im_close( out );
			return( NULL );
		}

		in = t;
	}

	if( in->Coding != IM_CODING_NONE ) {
		im_close( out );
		return( NULL );
	}

	if( in->Bands == 3 && in->Type == IM_TYPE_LCH ) {
		IMAGE *t[2];

                if( im_open_local_array( out, t, 2, "conv-1", "p" ) ||
			im_clip2fmt( in, t[0], IM_BANDFMT_FLOAT ) ||
			im_LCh2Lab( t[0], t[1] ) ) {
			im_close( out );
			return( NULL );
		}

		in = t[1];
	}

	if( in->Bands == 3 && in->Type == IM_TYPE_YXY ) {
		IMAGE *t[2];

                if( im_open_local_array( out, t, 2, "conv-1", "p" ) ||
			im_clip2fmt( in, t[0], IM_BANDFMT_FLOAT ) ||
			im_Yxy2XYZ( t[0], t[1] ) ) {
			im_close( out );
			return( NULL );
		}

		in = t[1];
	}

	if( in->Bands == 3 && in->Type == IM_TYPE_UCS ) {
		IMAGE *t[2];

                if( im_open_local_array( out, t, 2, "conv-1", "p" ) ||
			im_clip2fmt( in, t[0], IM_BANDFMT_FLOAT ) ||
			im_UCS2XYZ( t[0], t[1] ) ) {
			im_close( out );
			return( NULL );
		}

		in = t[1];
	}

	if( in->Bands == 3 && in->Type == IM_TYPE_LAB ) {
		IMAGE *t[2];

                if( im_open_local_array( out, t, 2, "conv-1", "p" ) ||
			im_clip2fmt( in, t[0], IM_BANDFMT_FLOAT ) ||
			im_Lab2XYZ( t[0], t[1] ) ) {
			im_close( out );
			return( NULL );
		}

		in = t[1];
	}

	if( in->Bands == 3 && in->Type == IM_TYPE_XYZ ) {
		IMAGE *t[2];

                if( im_open_local_array( out, t, 2, "conv-1", "p" ) ||
			im_clip2fmt( in, t[0], IM_BANDFMT_FLOAT ) ||
			im_XYZ2disp( t[0], t[1], im_col_displays( 7 ) ) ) {
			im_close( out );
			return( NULL );
		}

		in = t[1];
	}

	/* Cast to the output format.
	 */
	{
		IMAGE *t = im_open_local( out, "conv:1", "p" );

		if( !t || im_clip2fmt( in, t, format_table[in->BandFmt] ) ) {
			im_close( out );
			return( NULL );
		}

		in = t;
	}

	if( im_copy( in, out ) ) {
		im_close( out );
		return( NULL );
	}

	return( out );
}
int 
im__find_lroverlap( IMAGE *ref_in, IMAGE *sec_in, IMAGE *out,
	int bandno_in, 
	int xref, int yref, int xsec, int ysec, 
	int halfcorrelation, int halfarea,
	int *dx0, int *dy0,
	double *scale1, double *angle1, double *dx1, double *dy1 )
{
	Rect left, right, overlap;
	IMAGE *ref, *sec;
	IMAGE *t[6];
	TIE_POINTS points, *p_points;
	TIE_POINTS newpoints, *p_newpoints;
	int dx, dy;
	int i;

	/* Test cor and area.
	 */
	if( halfcorrelation < 0 || halfarea < 0 || 
		halfarea < halfcorrelation ) {
		im_error( "im_lrmosaic", "%s", _( "bad area parameters" ) );
		return( -1 );
	}

	/* Set positions of left and right.
	 */
	left.left = 0;
	left.top = 0;
	left.width = ref_in->Xsize;
	left.height = ref_in->Ysize;
	right.left = xref - xsec;
	right.top = yref - ysec;
	right.width = sec_in->Xsize;
	right.height = sec_in->Ysize;

	/* Find overlap.
	 */
	im_rect_intersectrect( &left, &right, &overlap );
	if( overlap.width < 2 * halfarea + 1 ||
		overlap.height < 2 * halfarea + 1 ) {
		im_error( "im_lrmosaic", 
			"%s", _( "overlap too small for search" ) );
		return( -1 );
	}

	/* Extract overlaps as 8-bit, 1 band.
	 */
	if( !(ref = im_open_local( out, "temp_one", "t" )) ||
		!(sec = im_open_local( out, "temp_two", "t" )) ||
		im_open_local_array( out, t, 6, "im_lrmosaic", "p" ) ||
		im_extract_area( ref_in, t[0], 
			overlap.left, overlap.top, 
			overlap.width, overlap.height ) ||
		im_extract_area( sec_in, t[1], 
			overlap.left - right.left, overlap.top - right.top, 
			overlap.width, overlap.height ) )
		return( -1 );
	if( ref_in->Coding == IM_CODING_LABQ ) {
		if( im_LabQ2Lab( t[0], t[2] ) || 
			im_LabQ2Lab( t[1], t[3] ) ||
	    		im_Lab2disp( t[2], t[4], im_col_displays( 1 ) ) || 
			im_Lab2disp( t[3], t[5], im_col_displays( 1 ) ) ||
			im_extract_band( t[4], ref, 1 ) ||
			im_extract_band( t[5], sec, 1 ) )
			return( -1 );
	}
	else if( ref_in->Coding == IM_CODING_NONE ) {
		if( im_extract_band( t[0], t[2], bandno_in ) ||
			im_extract_band( t[1], t[3], bandno_in ) ||
			im_scale( t[2], ref ) ||
			im_scale( t[3], sec ) )
			return( -1 );
	}
	else {
		im_error( "im_lrmosaic", "%s", _( "unknown Coding type" ) );
		return( -1 );
	}

	/* Initialise and fill TIE_POINTS 
	 */
	p_points = &points;
	p_newpoints = &newpoints;
	p_points->reference = ref_in->filename;
	p_points->secondary = sec_in->filename;
	p_points->nopoints = IM_MAXPOINTS;
	p_points->deltax = 0;
	p_points->deltay = 0;
	p_points->halfcorsize = halfcorrelation; 	
	p_points->halfareasize = halfarea;

	/* Initialise the structure 
	 */
	for( i = 0; i < IM_MAXPOINTS; i++ ) {
		p_points->x_reference[i] = 0;
		p_points->y_reference[i] = 0;
		p_points->x_secondary[i] = 0;
		p_points->y_secondary[i] = 0;
		p_points->contrast[i] = 0;
		p_points->correlation[i] = 0.0;
		p_points->dx[i] = 0.0;
		p_points->dy[i] = 0.0;
		p_points->deviation[i] = 0.0;
	}

	/* Search ref for possible tie-points. Sets: p_points->contrast, 
	 * p_points->x,y_reference.
 	 */
	if( im__lrcalcon( ref, p_points ) )
		return( -1 ); 

	/* For each candidate point, correlate against corresponding part of
	 * sec. Sets x,y_secondary and fills correlation and dx, dy.
 	 */
	if( im__chkpair( ref, sec, p_points ) )
		return( -1 );

	/* First call to im_clinear().
	 */
  	if( im__initialize( p_points ) )
		return( -1 );

	/* Improve the selection of tiepoints until all abs(deviations) are 
	 * < 1.0 by deleting all wrong points.
 	 */
	if( im__improve( p_points, p_newpoints ) )
		return( -1 );

	/* Average remaining offsets.
	 */
	if( im__avgdxdy( p_newpoints, &dx, &dy ) )
		return( -1 );

	/* Offset with overlap position.
	 */
	*dx0 = -right.left + dx;
	*dy0 = -right.top + dy;

	/* Write 1st order parameters too.
	 */
	*scale1 = newpoints.l_scale;
	*angle1 = newpoints.l_angle;
	*dx1 = newpoints.l_deltax;
	*dy1 = newpoints.l_deltay;

	return( 0 );
}
Exemple #10
0
int 
im__find_tboverlap( IMAGE *ref_in, IMAGE *sec_in, IMAGE *out,
	int bandno_in, 
	int xref, int yref, int xsec, int ysec, 
	int halfcorrelation, int halfarea,
	int *dx0, int *dy0,
	double *scale1, double *angle1, double *dx1, double *dy1 )
{
	IMAGE *ref, *sec;
	TIE_POINTS points, *p_points;		/* defined in mosaic.h */
	TIE_POINTS newpoints, *p_newpoints;
	int i;
	int dx, dy;

	Rect top, bottom, overlap;

	/* Check ref and sec are compatible.
	 */
	if( ref_in->Bands != sec_in->Bands || 
		ref_in->BandFmt != sec_in->BandFmt ||
		ref_in->Coding != sec_in->Coding ) {
		im_errormsg( "im_tbmosaic: input images incompatible" );
		return( -1 );
	}

	/* Test cor and area.
	 */
	if( halfcorrelation < 0 || halfarea < 0 || 
		halfarea < halfcorrelation ) {
		im_errormsg( "im_tbmosaic: bad area parameters" );
		return( -1 );
	}

	/* Set positions of top and bottom.
	 */
	top.left = 0;
	top.top = 0;
	top.width = ref_in->Xsize;
	top.height = ref_in->Ysize;
	bottom.left = xref - xsec;
	bottom.top = yref - ysec;
	bottom.width = sec_in->Xsize;
	bottom.height = sec_in->Ysize;

	/* Find overlap.
	 */
	im_rect_intersectrect( &top, &bottom, &overlap );
	if( overlap.width < 2*halfarea + 1 ||
		overlap.height < 2*halfarea + 1 ) {
		im_errormsg( "im_tbmosaic: overlap too small for search" );
		return( -1 );
	}

	/* Extract overlaps.
	 */
	ref = im_open_local( out, "temp_one", "t" );
	sec = im_open_local( out, "temp_two", "t" );
	if( !ref || !sec )
		return( -1 );
	if( ref_in->Coding == IM_CODING_LABQ ) {
		IMAGE *t1 = im_open_local( out, "temp:3", "p" );
		IMAGE *t2 = im_open_local( out, "temp:4", "p" );
		IMAGE *t3 = im_open_local( out, "temp:5", "p" );
		IMAGE *t4 = im_open_local( out, "temp:6", "p" );
		IMAGE *t5 = im_open_local( out, "temp:7", "p" );
		IMAGE *t6 = im_open_local( out, "temp:8", "p" );

		if( !t1 || !t2 || !t3 || !t4 || !t5 || !t6 )
			return( -1 );
		if( im_extract_area( ref_in, t1, 
			overlap.left, overlap.top, 
			overlap.width, overlap.height ) )
			return( -1 );
		if( im_extract_area( sec_in, t2, 
			overlap.left - bottom.left, overlap.top - bottom.top, 
			overlap.width, overlap.height ) )
			return( -1 );
		if( im_LabQ2Lab( t1, t3 ) || im_LabQ2Lab( t2, t4 ) ||
	    		im_Lab2disp( t3, t5, im_col_displays( 1 ) ) || 
			im_Lab2disp( t4, t6, im_col_displays( 1 ) ) )
			return( -1 );
		
		/* Extract the green.
		 */
		if( im_extract_band( t5, ref, 1 ) ||
			im_extract_band( t6, sec, 1 ) )
			return( -1 );
	}
	else if( ref_in->Coding == IM_CODING_NONE ) {
		IMAGE *t1 = im_open_local( out, "temp:9", "p" );
		IMAGE *t2 = im_open_local( out, "temp:10", "p" );
		IMAGE *t3 = im_open_local( out, "temp:11", "p" );
		IMAGE *t4 = im_open_local( out, "temp:12", "p" );

		if( !t1 || !t2 || !t3 || !t4 )
			return( -1 );
		if( im_extract_area( ref_in, t1, 
			overlap.left, overlap.top, 
			overlap.width, overlap.height ) )
			return( -1 );
		if( im_extract_area( sec_in, t2, 
			overlap.left - bottom.left, overlap.top - bottom.top, 
			overlap.width, overlap.height ) )
			return( -1 );
		if( im_extract_band( t1, t3, bandno_in ) ||
			im_extract_band( t2, t4, bandno_in ) )
			return( -1 );
		if( im_scale( t3, ref ) ||
			im_scale( t4, sec ) )
			return( -1 );
	}
	else {
		im_errormsg( "im_tbmosaic: unknown Coding type" );
		return( -1 );
	}

	/* Initialise and fill TIE_POINTS 
	 */
	p_points = &points;
	p_newpoints = &newpoints;
	p_points->reference = ref_in->filename;
	p_points->secondary = sec_in->filename;
	p_points->nopoints = IM_MAXPOINTS;
	p_points->deltax = 0;
	p_points->deltay = 0;
	p_points->halfcorsize = halfcorrelation; 	
	p_points->halfareasize = halfarea;

	/* Initialise the structure 
	 */
	for( i = 0; i < IM_MAXPOINTS; i++ ) {
		p_points->x_reference[i] = 0;
		p_points->y_reference[i] = 0;
		p_points->x_secondary[i] = 0;
		p_points->y_secondary[i] = 0;
		p_points->contrast[i] = 0;
		p_points->correlation[i] = 0.0;
		p_points->dx[i] = 0.0;
		p_points->dy[i] = 0.0;
		p_points->deviation[i] = 0.0;
	}

	/* Search ref for possible tie-points. Sets: p_points->contrast, 
	 * p_points->x,y_reference.
 	 */
	if( im__tbcalcon( ref, p_points ) )
		return( -1 ); 

	/* For each candidate point, correlate against corresponding part of
	 * sec. Sets x,y_secondary and fills correlation and dx, dy.
 	 */
	if( im__chkpair( ref, sec, p_points ) )
		return( -1 );

	/* First call to im_clinear().
	 */
  	if( im__initialize( p_points ) )
		return( -1 );

	/* Improve the selection of tiepoints until all abs(deviations) are 
	 * < 1.0 by deleting all wrong points.
 	 */
	if( im__improve( p_points, p_newpoints ) )
		return( -1 );

	/* Average remaining offsets.
	 */
	if( im__avgdxdy( p_newpoints, &dx, &dy ) )
		return( -1 );

	/* Offset with overlap position.
	 */
	*dx0 = -bottom.left + dx;
	*dy0 = -bottom.top + dy;

	/* Write 1st order parameters too.
	 */
	*scale1 = newpoints.l_scale;
	*angle1 = newpoints.l_angle;
	*dx1 = newpoints.l_deltax;
	*dy1 = newpoints.l_deltay;

	return( 0 );
}