Move colour scale and pixbuf rendering to libcrystfel

Also, split into two files (colscale and render), and remove TIFF stuff.

7 files changed, 503 insertions, 175 deletions

diff --git a/libcrystfel/CMakeLists.txt b/libcrystfel/CMakeLists.txt
index 15d4ba19..1e30bf81 100644
--- a/libcrystfel/CMakeLists.txt
+++ b/libcrystfel/CMakeLists.txt
@@ -76,6 +76,7 @@ set(LIBCRYSTFEL_SOURCES
     src/rational.c
     src/spectrum.c
     src/datatemplate.c
+    src/colscale.c
     ${BISON_symopp_OUTPUTS}
     ${FLEX_symopl_OUTPUTS}
 )
@@ -119,6 +120,7 @@ set(LIBCRYSTFEL_HEADERS
     src/rational.h
     src/spectrum.h
     src/datatemplate.h
+    src/colscale.h
 )
 
 if (DOXYGEN_FOUND)
@@ -177,6 +179,11 @@ if (CURSES_FOUND)
   target_link_libraries(${PROJECT_NAME} PRIVATE ${CURSES_LIBRARIES})
 endif (CURSES_FOUND)
 
+if (GDKPIXBUF_FOUND)
+  target_include_directories(${PROJECT_NAME} PRIVATE ${GDKPIXBUF_INCLUDE_DIRS})
+  target_link_libraries(${PROJECT_NAME} PRIVATE ${GDKPIXBUF_LIBRARIES})
+endif (GDKPIXBUF_FOUND)
+
 target_compile_options(${PROJECT_NAME} PRIVATE -Wall)
 set_target_properties(${PROJECT_NAME} PROPERTIES PUBLIC_HEADER "${LIBCRYSTFEL_HEADERS}")
 
diff --git a/libcrystfel/config.h.cmake.in b/libcrystfel/config.h.cmake.in
index 731e6fe0..3433e043 100644
--- a/libcrystfel/config.h.cmake.in
+++ b/libcrystfel/config.h.cmake.in
@@ -8,6 +8,7 @@
 #cmakedefine HAVE_FDIP
 #cmakedefine HAVE_CURSES
 #cmakedefine HAVE_GZBUFFER
+#cmakedefine HAVE_GDKPIXBUF
 
 #cmakedefine HAVE_FORKPTY_PTY_H
 #cmakedefine HAVE_FORKPTY_UTIL_H
diff --git a/libcrystfel/src/colscale.c b/libcrystfel/src/colscale.c
new file mode 100644
index 00000000..d541b384
--- /dev/null
+++ b/libcrystfel/src/colscale.c
@@ -0,0 +1,246 @@
+/*
+ * colscale.c
+ *
+ * Colour scales
+ *
+ * Copyright © 2012-2020 Deutsches Elektronen-Synchrotron DESY,
+ *                       a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2009-2012,2014 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+
+#include <stdlib.h>
+#include <math.h>
+#include <stdint.h>
+
+#include "colscale.h"
+
+/** \file colscale.h */
+
+static void render_rgb(double val, double max,
+                       double *rp, double *gp, double *bp)
+{
+	int s;
+	double p;
+	double r, g, b;
+
+	s = val / (max/6);
+	p = fmod(val, max/6.0);
+	p /= (max/6.0);
+
+	r = 0.0;  g = 0.0;  b = 0.0;
+
+	if ( (val < 0.0) ) {
+		p = fabs(val) / (max/6.0);
+		*rp = 0.0;
+		*gp = 0.5*p;
+		*bp = 0.0;
+		return;
+	}
+	if ( (val > max) ) {
+		s = 6;
+	}
+	switch ( s ) {
+
+		case 0 :	/* Black to blue */
+		r = 0;  g = 0;  b = p;
+		break;
+
+		case 1 :	/* Blue to pink */
+		r = p;  g = 0;  b = 1.0;
+		break;
+
+		case 2 :	/* Pink to red */
+		r = 1.0;  g = 0;  b = (1.0-p)*1.0;
+		break;
+
+		case 3 :	/* Red to Orange */
+		r = 1.0;  g = 0.5*p;  b = 0;
+		break;
+
+		case 4 :	/* Orange to Yellow */
+		r = 1.0;  g = 0.5 + 0.5*p;  b = 0;
+		break;
+
+		case 5 :	/* Yellow to White */
+		r = 1.0;  g = 1.0;  b = 1.0*p;
+		break;
+
+		case 6 :	/* Pixel has hit the maximum value */
+		r = 1.0;  g = 1.0;  b = 1.0;
+		break;
+
+	}
+
+	*rp = r;
+	*gp = g;
+	*bp = b;
+}
+
+
+static void render_geoptimiser(double val, double max,
+                               double *rp, double *gp, double *bp)
+{
+	double r;
+	double p;
+
+	r = val/max;
+
+	if ( val < 0.0 ) {
+		*rp = 0.0;
+		*gp = 0.0;
+		*bp = 0.0;
+		return;
+	}
+
+	if ( r >= 0.0 && r < 0.059 ) {
+		p = (r-0.0)/(0.059-0.0);
+		*rp = 0.0;
+		*gp = 0.0;
+		*bp = ((91.0/256.0)-0.0)*p;
+		return;
+	}
+
+	if ( r >= 0.059 && r < 0.220 ) {
+		p = (r-0.059)/(0.220-0.059);
+		*rp = ((122.0/256.0)-0.0)*p;
+		*gp = 0.0;
+		*bp = ((227.0/256.0)-(91.0/256.0))*p+(91.0/256.0);
+		return;
+	}
+
+	if ( r >= 0.220 && r < 0.376 ) {
+		p = (r-0.220)/(0.376-0.220);
+		*rp = ((195.0/256.0)-(122.0/256.0))*p+(122.0/256.0);
+		*gp = 0.0;
+		*bp = ((93.0/256.0)-(227.0/256.0))*p+(227.0/256.0);
+		return;
+	}
+
+	if ( r >= 0.376 && r < 0.498 ) {
+		p = (r-0.376)/(0.498-0.376);
+		*rp = ((238.0/256.0)-(195.0/256.0))*p+(195.0/256.0);
+		*gp = ((76.0/256.0)-0.0)*p;
+		*bp = (0.0-(93.0/256.0))*p+(93.0/256.0);
+		return;
+	}
+
+	if ( r >= 0.498 && r < 0.564 ) {
+		p = (r-0.498)/(0.564-0.498);
+		*rp = (1.0-(238.0/256.0))*p+(238.0/256.0);
+		*gp = ((117.0/256.0)-(76.0/256.0))*p+(76.0/256.0);
+		*bp = 0.0;
+		return;
+	}
+
+	if ( r >= 0.564 && r < 0.815 ) {
+		p = (r-0.564)/(0.815-0.564);
+		*rp = 1.0;
+		*gp = ((234.0/256.0)-(117.0/256.0))*p+(117.0/256.0);
+		*bp = 0.0;
+		return;
+	}
+
+	if ( r >= 0.815 && r < 1.0 ) {
+		p = (r-0.815)/(1.0-0.815);
+		*rp = 1.0;
+		*gp = (1.0-(234.0/256.0))*p+(234.0/256.0);
+		*bp = (1.0-0.0)*p;
+		return;
+	}
+
+	if ( r >= 1.0 ) {
+		*rp = 1.0; *gp = 1.0; *bp = 1.0;
+		return;
+	}
+}
+
+
+static void render_ratio(double val, double max,
+                         double *rp, double *gp, double *bp)
+{
+	if ( val <= 1.0 ) {
+		render_rgb(val, 2.0, rp, gp, bp);
+	} else {
+		/* Your homework is to simplify this expression */
+		val = ((val-1.0)/(max-1.0)) * (max/2.0) + max/2.0;
+		render_rgb(val, max, rp, gp, bp);
+	}
+}
+
+
+static void render_mono(double val, double max,
+                        double *rp, double *gp, double *bp)
+{
+	double p;
+	p = val / max;
+	if ( val < 0.0 ) p = 0.0;
+	if ( val > max ) p = 1.0;
+	*rp = p;
+	*gp = p;
+	*bp = p;
+}
+
+
+static void render_invmono(double val, double max,
+                           double *rp, double *gp, double *bp)
+{
+	double p;
+	p = val / max;
+	p = 1.0 - p;
+	if ( val < 0.0 ) p = 1.0;
+	if ( val > max ) p = 0.0;
+	*rp = p;
+	*gp = p;
+	*bp = p;
+}
+
+
+void render_scale(double val, double max, int scale,
+                  double *rp, double *gp, double *bp)
+{
+	switch ( scale ) {
+
+		case SCALE_COLOUR :
+		render_rgb(val, max, rp, gp, bp);
+		break;
+
+		case SCALE_MONO :
+		render_mono(val, max, rp, gp, bp);
+		break;
+
+		case SCALE_INVMONO :
+		render_invmono(val, max, rp, gp, bp);
+		break;
+
+		case SCALE_RATIO :
+		render_ratio(val, max, rp, gp, bp);
+		break;
+
+		case SCALE_GEOPTIMISER :
+		render_geoptimiser(val, max, rp, gp, bp);
+		break;
+	}
+}
diff --git a/libcrystfel/src/colscale.h b/libcrystfel/src/colscale.h
new file mode 100644
index 00000000..41e8c9e8
--- /dev/null
+++ b/libcrystfel/src/colscale.h
@@ -0,0 +1,62 @@
+/*
+ * colscale.h
+ *
+ * Colour scales
+ *
+ * Copyright © 2012-2020 Deutsches Elektronen-Synchrotron DESY,
+ *                       a research centre of the Helmholtz Association.
+ *
+ * Authors:
+ *   2009-2012 Thomas White <taw@physics.org>
+ *
+ * This file is part of CrystFEL.
+ *
+ * CrystFEL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * CrystFEL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with CrystFEL.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifndef COLSCALE_H
+#define COLSCALE_H
+
+/**
+ * \file colscale.h
+ * Colour scales for rendering
+ */
+
+enum {
+	SCALE_COLOUR,
+	SCALE_MONO,
+	SCALE_INVMONO,
+	SCALE_RATIO,
+	SCALE_GEOPTIMISER
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Colour scale lookup */
+extern void render_scale(double val, double max, int scale,
+                         double *rp, double *gp, double *bp);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* COLSCALE_H */
diff --git a/libcrystfel/src/peaks.h b/libcrystfel/src/peaks.h
index 6e61758c..89388652 100644
--- a/libcrystfel/src/peaks.h
+++ b/libcrystfel/src/peaks.h
@@ -39,6 +39,7 @@
 
 #include "reflist.h"
 #include "crystal.h"
+#include "image.h"
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/libcrystfel/src/render.c b/libcrystfel/src/render.c
index 284f4c46..b8bcae4d 100644
--- a/libcrystfel/src/render.c
+++ b/libcrystfel/src/render.c
@@ -1,7 +1,7 @@
 /*
  * render.c
  *
- * Render a high dynamic range buffer in some sensible way
+ * Render image data to GdkPixbufs
  *
  * Copyright © 2012-2020 Deutsches Elektronen-Synchrotron DESY,
  *                       a research centre of the Helmholtz Association.
@@ -35,217 +35,229 @@
 #include <math.h>
 #include <stdint.h>
 
+#ifdef HAVE_GDKPIXBUF
+#include <gdk-pixbuf/gdk-pixbuf.h>
+#endif
+
 
-#include "hdf5-file.h"
 #include "render.h"
 #include "peaks.h"
-#include "filters.h"
-#include "utils.h"
+#include "colscale.h"
 
 /** \file render.h */
 
-static void render_rgb(double val, double max,
-                       double *rp, double *gp, double *bp)
+static float *get_binned_panel(struct image *image, int binning,
+                               int pi, double *max, int *pw, int *ph)
 {
-	int s;
-	double p;
-	double r, g, b;
-
-	s = val / (max/6);
-	p = fmod(val, max/6.0);
-	p /= (max/6.0);
-
-	r = 0.0;  g = 0.0;  b = 0.0;
-
-	if ( (val < 0.0) ) {
-		p = fabs(val) / (max/6.0);
-		*rp = 0.0;
-		*gp = 0.5*p;
-		*bp = 0.0;
-		return;
-	}
-	if ( (val > max) ) {
-		s = 6;
-	}
-	switch ( s ) {
+	float *data;
+	int x, y;
+	int w, h;
+	struct panel *p = &image->det->panels[pi];
+
+	/* Some pixels might get discarded */
+	w = p->w / binning;
+	h = p->h / binning;
+	*pw = w;
+	*ph = h;
+
+	data = malloc(w*h*sizeof(float));
 
-		case 0 :	/* Black to blue */
-		r = 0;  g = 0;  b = p;
-		break;
+	*max = 0.0;
+	for ( x=0; x<w; x++ ) {
+	for ( y=0; y<h; y++ ) {
 
-		case 1 :	/* Blue to pink */
-		r = p;  g = 0;  b = 1.0;
-		break;
+		double total;
+		size_t xb, yb;
+		int bad = 0;
+		double val;
 
-		case 2 :	/* Pink to red */
-		r = 1.0;  g = 0;  b = (1.0-p)*1.0;
-		break;
+		total = 0;
+		for ( xb=0; xb<binning; xb++ ) {
+		for ( yb=0; yb<binning; yb++ ) {
 
-		case 3 :	/* Red to Orange */
-		r = 1.0;  g = 0.5*p;  b = 0;
-		break;
+			double v;
+			int fs, ss;
 
-		case 4 :	/* Orange to Yellow */
-		r = 1.0;  g = 0.5 + 0.5*p;  b = 0;
-		break;
+			fs = binning*x+xb;
+			ss = binning*y+yb;
+			v = image->dp[pi][fs+ss*p->w];
+			total += v;
 
-		case 5 :	/* Yellow to White */
-		r = 1.0;  g = 1.0;  b = 1.0*p;
-		break;
+			if ( (image->bad != NULL)
+			  && (image->bad[pi][fs+ss*p->w]) ) bad = 1;
 
-		case 6 :	/* Pixel has hit the maximum value */
-		r = 1.0;  g = 1.0;  b = 1.0;
-		break;
+		}
+		}
 
+		val = total / ((double)binning * (double)binning);
+
+		if ( bad ) {
+			data[x+w*y] = -INFINITY;
+		} else {
+			data[x+w*y] = val;
+			if ( val > *max ) *max = val;
+		}
+
+	}
 	}
 
-	*rp = r;
-	*gp = g;
-	*bp = b;
+	return data;
+}
+
+
+#ifdef HAVE_GDKPIXBUF
+
+/* NB This function is shared between render_get_image() and
+ * render_get_colour_scale() */
+static void render_free_data(guchar *data, gpointer p)
+{
+	free(data);
 }
 
 
-static void render_geoptimiser(double val, double max,
-                               double *rp, double *gp, double *bp)
+static GdkPixbuf *render_panel(float *hdr, int scale, double max, int w, int h)
 {
-	double r;
-	double p;
+	guchar *data;
+	int x, y;
 
-	r = val/max;
+	/* Rendered (colourful) version */
+	data = malloc(3*w*h);
+	if ( data == NULL ) return NULL;
 
-	if ( val < 0.0 ) {
-		*rp = 0.0;
-		*gp = 0.0;
-		*bp = 0.0;
-		return;
-	}
+	/* These x,y coordinates are measured relative to the bottom-left
+	 * corner */
+	for ( y=0; y<h; y++ ) {
+	for ( x=0; x<w; x++ ) {
 
-	if ( r >= 0.0 && r < 0.059 ) {
-		p = (r-0.0)/(0.059-0.0);
-		*rp = 0.0;
-		*gp = 0.0;
-		*bp = ((91.0/256.0)-0.0)*p;
-		return;
-	}
+		double val;
+		double r, g, b;
 
-	if ( r >= 0.059 && r < 0.220 ) {
-		p = (r-0.059)/(0.220-0.059);
-		*rp = ((122.0/256.0)-0.0)*p;
-		*gp = 0.0;
-		*bp = ((227.0/256.0)-(91.0/256.0))*p+(91.0/256.0);
-		return;
-	}
+		val = hdr[x+w*y];
 
-	if ( r >= 0.220 && r < 0.376 ) {
-		p = (r-0.220)/(0.376-0.220);
-		*rp = ((195.0/256.0)-(122.0/256.0))*p+(122.0/256.0);
-		*gp = 0.0;
-		*bp = ((93.0/256.0)-(227.0/256.0))*p+(227.0/256.0);
-		return;
-	}
+		if ( val > -INFINITY ) {
 
-	if ( r >= 0.376 && r < 0.498 ) {
-		p = (r-0.376)/(0.498-0.376);
-		*rp = ((238.0/256.0)-(195.0/256.0))*p+(195.0/256.0);
-		*gp = ((76.0/256.0)-0.0)*p;
-		*bp = (0.0-(93.0/256.0))*p+(93.0/256.0);
-		return;
-	}
+			render_scale(val, max, scale, &r, &g, &b);
+
+			/* Stuff inside square brackets makes this pixel go to
+			 * the expected location in the pixbuf (which measures
+			 * from the top-left corner */
+			data[3*( x+w*y )+0] = 255*r;
+			data[3*( x+w*y )+1] = 255*g;
+			data[3*( x+w*y )+2] = 255*b;
+
+		} else {
+
+			data[3*( x+w*y )+0] = 30;
+			data[3*( x+w*y )+1] = 20;
+			data[3*( x+w*y )+2] = 0;
 
-	if ( r >= 0.498 && r < 0.564 ) {
-		p = (r-0.498)/(0.564-0.498);
-		*rp = (1.0-(238.0/256.0))*p+(238.0/256.0);
-		*gp = ((117.0/256.0)-(76.0/256.0))*p+(76.0/256.0);
-		*bp = 0.0;
-		return;
+		}
+
+	}
 	}
 
-	if ( r >= 0.564 && r < 0.815 ) {
-		p = (r-0.564)/(0.815-0.564);
-		*rp = 1.0;
-		*gp = ((234.0/256.0)-(117.0/256.0))*p+(117.0/256.0);
-		*bp = 0.0;
-		return;
+	/* Create the pixbuf from the 8-bit display data */
+	return gdk_pixbuf_new_from_data(data, GDK_COLORSPACE_RGB, FALSE, 8,
+					w, h, w*3, render_free_data, NULL);
+
+}
+
+
+/* Render an image into multiple pixbufs according to geometry */
+GdkPixbuf **render_panels(struct image *image,
+                          int binning, int scale, double boost,
+                          int *n_pixbufs)
+{
+	int i;
+	int np = image->det->n_panels;
+	GdkPixbuf **pixbufs;
+	float **hdrs;
+	double max;
+	int *ws, *hs;
+
+	hdrs = calloc(np, sizeof(float *));
+	ws = calloc(np, sizeof(int));
+	hs = calloc(np, sizeof(int));
+	if ( (hdrs == NULL) || (ws == NULL) || (hs == NULL) ) {
+		*n_pixbufs = 0;
+		return NULL;
 	}
 
-	if ( r >= 0.815 && r < 1.0 ) {
-		p = (r-0.815)/(1.0-0.815);
-		*rp = 1.0;
-		*gp = (1.0-(234.0/256.0))*p+(234.0/256.0);
-		*bp = (1.0-0.0)*p;
-		return;
+	/* Find overall max value for whole image */
+	max = 0.0;
+	for ( i=0; i<np; i++ ) {
+		double this_max = 0.0;
+		hdrs[i] = get_binned_panel(image, binning, i, &this_max,
+		                           &ws[i], &hs[i]);
+		if ( this_max > max ) max = this_max;
 	}
 
-	if ( r >= 1.0 ) {
-		*rp = 1.0; *gp = 1.0; *bp = 1.0;
-		return;
+	max /= boost;
+	if ( max <= 6 ) { max = 10; }
+
+	pixbufs = calloc(np, sizeof(GdkPixbuf*));
+	if ( pixbufs == NULL ) {
+		*n_pixbufs = 0;
+		return NULL;
 	}
-}
 
+	for ( i=0; i<np; i++ ) {
+
+		pixbufs[i] = render_panel(hdrs[i], scale, max, ws[i], hs[i]);
+
+		free(hdrs[i]);
 
-static void render_ratio(double val, double max,
-                         double *rp, double *gp, double *bp)
-{
-	if ( val <= 1.0 ) {
-		render_rgb(val, 2.0, rp, gp, bp);
-	} else {
-		/* Your homework is to simplify this expression */
-		val = ((val-1.0)/(max-1.0)) * (max/2.0) + max/2.0;
-		render_rgb(val, max, rp, gp, bp);
 	}
-}
 
+	free(hdrs);
+	free(ws);
+	free(hs);
+	*n_pixbufs = np;
 
-static void render_mono(double val, double max,
-                        double *rp, double *gp, double *bp)
-{
-	double p;
-	p = val / max;
-	if ( val < 0.0 ) p = 0.0;
-	if ( val > max ) p = 1.0;
-	*rp = p;
-	*gp = p;
-	*bp = p;
+	return pixbufs;
 }
 
 
-static void render_invmono(double val, double max,
-                           double *rp, double *gp, double *bp)
+GdkPixbuf *render_get_colour_scale(size_t w, size_t h, int scale)
 {
-	double p;
-	p = val / max;
-	p = 1.0 - p;
-	if ( val < 0.0 ) p = 1.0;
-	if ( val > max ) p = 0.0;
-	*rp = p;
-	*gp = p;
-	*bp = p;
-}
+	guchar *data;
+	size_t x, y;
+	int max;
 
+	data = malloc(3*w*h);
+	if ( data == NULL ) return NULL;
 
-void render_scale(double val, double max, int scale,
-                  double *rp, double *gp, double *bp)
-{
-	switch ( scale ) {
+	max = h-(h/6);
 
-		case SCALE_COLOUR :
-		render_rgb(val, max, rp, gp, bp);
-		break;
+	for ( y=0; y<h; y++ ) {
 
-		case SCALE_MONO :
-		render_mono(val, max, rp, gp, bp);
-		break;
+		double r, g, b;
+		int val;
 
-		case SCALE_INVMONO :
-		render_invmono(val, max, rp, gp, bp);
-		break;
+		val = y-(h/6);
 
-		case SCALE_RATIO :
-		render_ratio(val, max, rp, gp, bp);
-		break;
+		render_scale(val, max, scale, &r, &g, &b);
 
-		case SCALE_GEOPTIMISER :
-		render_geoptimiser(val, max, rp, gp, bp);
-		break;
+		data[3*( 0+w*(h-1-y) )+0] = 0;
+		data[3*( 0+w*(h-1-y) )+1] = 0;
+		data[3*( 0+w*(h-1-y) )+2] = 0;
+		for ( x=1; x<w; x++ ) {
+			data[3*( x+w*(h-1-y) )+0] = 255*r;
+			data[3*( x+w*(h-1-y) )+1] = 255*g;
+			data[3*( x+w*(h-1-y) )+2] = 255*b;
+		}
+
+	}
+
+	y = h/6;
+	for ( x=1; x<w; x++ ) {
+		data[3*( x+w*(h-1-y) )+0] = 255;
+		data[3*( x+w*(h-1-y) )+1] = 255;
+		data[3*( x+w*(h-1-y) )+2] = 255;
 	}
+
+	return gdk_pixbuf_new_from_data(data, GDK_COLORSPACE_RGB, FALSE, 8,
+					w, h, w*3, render_free_data, NULL);
 }
+
+#endif /* HAVE_GDKPIXBUF */
diff --git a/libcrystfel/src/render.h b/libcrystfel/src/render.h
index a3292515..411c50ce 100644
--- a/libcrystfel/src/render.h
+++ b/libcrystfel/src/render.h
@@ -1,7 +1,7 @@
 /*
  * render.h
  *
- * Render a high dynamic range buffer in some sensible way
+ * Render image data to GdkPixbufs
  *
  * Copyright © 2012-2020 Deutsches Elektronen-Synchrotron DESY,
  *                       a research centre of the Helmholtz Association.
@@ -33,27 +33,26 @@
 #ifndef RENDER_H
 #define RENDER_H
 
+#include "image.h"
+
 /**
  * \file render.h
- * Colour scale for rendering
+ * Render image data to GdkPixbufs
  */
 
-enum {
-	SCALE_COLOUR,
-	SCALE_MONO,
-	SCALE_INVMONO,
-	SCALE_RATIO,
-	SCALE_GEOPTIMISER
-};
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-/* Colour scale lookup */
-extern void render_scale(double val, double max, int scale,
-                         double *rp, double *gp, double *bp);
+#ifdef HAVE_GDKPIXBUF
+#include <gdk-pixbuf/gdk-pixbuf.h>
+
+extern GdkPixbuf *render_get_colour_scale(size_t w, size_t h, int scale);
 
+extern GdkPixbuf **render_panels(struct image *image,
+                                 int binning, int scale, double boost,
+                                 int *n_pixbufs);
+#endif  /* HAVE_GDKPIXBUF */
 
 #ifdef __cplusplus
 }