diff --git a/TODO b/TODO
index 701fda57..32b3a8bf 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,24 @@
+- shrink does not auto unpack labq or rad, should it?
+
+- others .. differences in:
+
+grep -l CODING_LABQ */*.c
+conversion/join.c
+conversion/msb.c
+inplace/im_draw_mask.c
+resample/shrink.c
+
+grep -l CODING_RAD */*.c
+conversion/embed.c
+inplace/flood.c
+inplace/im_draw_image.c
+
+- add unpack everywhere, eg. arithmetic
+
+
+
+
+- move vips__image_decode() into the public API
 
 - need to do mosaicing and inplace, plus im_label_regions in morph
 
diff --git a/libvips/convolution/conv.c b/libvips/convolution/conv.c
index 441cb550..3608b031 100644
--- a/libvips/convolution/conv.c
+++ b/libvips/convolution/conv.c
@@ -65,7 +65,10 @@ vips_conv_build( VipsObject *object )
 	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
 	VipsConvolution *convolution = (VipsConvolution *) object;
 	VipsConv *conv = (VipsConv *) object;
+	VipsImage **t = (VipsImage **) 
+		vips_object_local_array( object, 4 );
 
+	VipsImage *in;
 	INTMASK *imsk;
 	DOUBLEMASK *dmsk;
 
@@ -74,6 +77,8 @@ vips_conv_build( VipsObject *object )
 	if( VIPS_OBJECT_CLASS( vips_conv_parent_class )->build( object ) )
 		return( -1 );
 
+	in = convolution->in;
+
 	/*
 	printf( "vips_conv_build: convolving with:\n" );
 	vips_matrixprint( convolution->M, NULL ); 
@@ -86,19 +91,25 @@ vips_conv_build( VipsObject *object )
 		!im_local_dmask( convolution->out, dmsk ) )
 		return( -1 ); 
 
+	/* Unpack for processing.
+	 */
+	if( vips__image_decode( in, &t[0] ) )
+		return( -1 );
+	in = t[0];
+
 	switch( conv->precision ) { 
 	case VIPS_PRECISION_INTEGER:
-		if( im_conv( convolution->in, convolution->out, imsk ) )
+		if( im_conv( in, convolution->out, imsk ) )
 			return( -1 ); 
 		break;
 
 	case VIPS_PRECISION_FLOAT:
-		if( im_conv_f( convolution->in, convolution->out, dmsk ) )
+		if( im_conv_f( in, convolution->out, dmsk ) )
 			return( -1 ); 
 		break;
 
 	case VIPS_PRECISION_APPROXIMATE:
-		if( im_aconv( convolution->in, convolution->out, dmsk, 
+		if( im_aconv( in, convolution->out, dmsk, 
 			conv->layers, conv->cluster ) )
 			return( -1 ); 
 		break;
diff --git a/libvips/include/vips/internal.h b/libvips/include/vips/internal.h
index 39c233b6..e29d64df 100644
--- a/libvips/include/vips/internal.h
+++ b/libvips/include/vips/internal.h
@@ -297,6 +297,8 @@ IMAGE *vips__deprecated_open_write( const char *filename );
 
 int vips__input_interpolate_init( im_object *obj, char *str );
 
+int vips__image_decode( VipsImage *in, VipsImage **out );
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus*/
diff --git a/libvips/resample/affine.c b/libvips/resample/affine.c
index a8988f3e..c8e325f1 100644
--- a/libvips/resample/affine.c
+++ b/libvips/resample/affine.c
@@ -373,13 +373,33 @@ vips_affine_gen( VipsRegion *or, void *seq, void *a, void *b, gboolean *stop )
 	return( 0 );
 }
 
+/* Unpack to a format that we can compute with.
+ */
+int
+vips__image_decode( VipsImage *in, VipsImage **out )
+{
+	if( in->Coding == VIPS_CODING_LABQ ) {
+		if( vips_LabQ2LabS( in, out, NULL ) )
+			return( -1 );
+	} 
+	else if( in->Coding == VIPS_CODING_RAD ) {
+		if( vips_rad2float( in, out, NULL ) )
+			return( -1 );
+	}
+	else {
+		if( vips_copy( in, out, NULL ) )
+			return( -1 );
+	}
+
+	return( 0 );
+}
+
 static int
 vips_affine_build( VipsObject *object )
 {
 	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
 	VipsResample *resample = VIPS_RESAMPLE( object );
 	VipsAffine *affine = (VipsAffine *) object;
-
 	VipsImage **t = (VipsImage **) 
 		vips_object_local_array( object, 4 );
 
@@ -465,11 +485,9 @@ vips_affine_build( VipsObject *object )
 
 	/* Unpack labq for processing.
 	 */
-	if( in->Coding == VIPS_CODING_LABQ ) {
-		if( vips_LabQ2LabS( in, &t[0], NULL ) )
-			return( -1 );
-		in = t[0];
-	}
+	if( vips__image_decode( in, &t[0] ) )
+		return( -1 );
+	in = t[0];
 
 	/* Add new pixels around the input so we can interpolate at the edges.
 	 */
diff --git a/libvips/resample/shrink.c b/libvips/resample/shrink.c
index d15731e7..f70b4ded 100644
--- a/libvips/resample/shrink.c
+++ b/libvips/resample/shrink.c
@@ -310,6 +310,10 @@ vips_shrink_build( VipsObject *object )
 	VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
 	VipsResample *resample = VIPS_RESAMPLE( object );
 	VipsShrink *shrink = (VipsShrink *) object;
+	VipsImage **t = (VipsImage **) 
+		vips_object_local_array( object, 1 );
+
+	VipsImage *in;
 
 	if( VIPS_OBJECT_CLASS( vips_shrink_parent_class )->build( object ) )
 		return( -1 );
@@ -318,7 +322,9 @@ vips_shrink_build( VipsObject *object )
 	shrink->mh = ceil( shrink->yshrink );
 	shrink->np = shrink->mw * shrink->mh;
 
-	if( vips_check_noncomplex( class->nickname, resample->in ) )
+	in = resample->in; 
+
+	if( vips_check_noncomplex( class->nickname, in ) )
 		return( -1 );
 
 	if( shrink->xshrink < 1.0 || 
@@ -336,14 +342,20 @@ vips_shrink_build( VipsObject *object )
 
 	if( shrink->xshrink == 1.0 &&
 		shrink->yshrink == 1.0 )
-		return( vips_image_write( resample->in, resample->out ) );
+		return( vips_image_write( in, resample->out ) );
+
+	/* Unpack for processing.
+	 */
+	if( vips__image_decode( in, &t[0] ) )
+		return( -1 );
+	in = t[0];
 
 	/* THINSTRIP will work, anything else will break seq mode. If you 
 	 * combine shrink with conv you'll need to use a line cache to maintain
 	 * sequentiality.
 	 */
 	if( vips_image_pipelinev( resample->out, 
-		VIPS_DEMAND_STYLE_THINSTRIP, resample->in, NULL ) )
+		VIPS_DEMAND_STYLE_THINSTRIP, in, NULL ) )
 		return( -1 );
 
 	/* Size output. Note: we round the output width down!
@@ -352,8 +364,8 @@ vips_shrink_build( VipsObject *object )
 	 * example, vipsthumbnail knows the true shrink factor (including the
 	 * fractional part), we just see the integer part here.
 	 */
-	resample->out->Xsize = resample->in->Xsize / shrink->xshrink;
-	resample->out->Ysize = resample->in->Ysize / shrink->yshrink;
+	resample->out->Xsize = in->Xsize / shrink->xshrink;
+	resample->out->Ysize = in->Ysize / shrink->yshrink;
 	if( resample->out->Xsize <= 0 || 
 		resample->out->Ysize <= 0 ) {
 		vips_error( class->nickname, 
@@ -363,7 +375,7 @@ vips_shrink_build( VipsObject *object )
 
 #ifdef DEBUG
 	printf( "vips_shrink_build: shrinking %d x %d image to %d x %d\n", 
-		resample->in->Xsize, resample->in->Ysize, 
+		in->Xsize, in->Ysize, 
 		resample->out->Xsize, resample->out->Ysize );  
 	printf( "vips_shrink_build: %d x %d block average\n", 
 		shrink->mw, shrink->mh ); 
@@ -371,7 +383,7 @@ vips_shrink_build( VipsObject *object )
 
 	if( vips_image_generate( resample->out,
 		vips_shrink_start, vips_shrink_gen, vips_shrink_stop, 
-		resample->in, shrink ) )
+		in, shrink ) )
 		return( -1 );
 
 	return( 0 );