Merge branch '8.10'

ChangeLog

@@ -11,6 +11,8 @@
 - in jpegsave, don't set JFIF resolution if we set EXIF resolution
 - bump minimum libheif version to 1.3 [lovell]
 - dzsave in iiif mode could set info.json dimensions off by one [Linden6]
+- pdfload allows dpi and scale to both be set [le0daniel]
+- allow gaussblur sigma zero, meaning no blur
 
 9/8/20 started 8.10.1
 - fix markdown -> xml conversion in doc generation

libvips/convolution/gaussblur.c

@@ -4,6 +4,9 @@
  * 	- from vips_sharpen()
  * 19/11/14
  * 	- change parameters to be more imagemagick-like
+ * 21/9/20
+ * 	- allow sigma zero, meaning no blur
+ * 	- sigma < 0.2 is just copy
  */
 
 /*
@@ -73,23 +76,33 @@ vips_gaussblur_build( VipsObject *object )
 	if( VIPS_OBJECT_CLASS( vips_gaussblur_parent_class )->build( object ) )
 		return( -1 );
 
-	if( vips_gaussmat( &t[0], gaussblur->sigma, gaussblur->min_ampl, 
-		"separable", TRUE,
-		"precision", gaussblur->precision,
-		NULL ) )
-		return( -1 ); 
+	/* vips_gaussmat() will make a 1x1 pixel mask for anything smaller than
+	 * this.
+	 */
+	if( sigma < 0.2 ) {
+		if( vips_copy( gaussblur->in, &t[1], NULL ) )
+			return( -1 ); 
+	}
+	else {
+		if( vips_gaussmat( &t[0], 
+			gaussblur->sigma, gaussblur->min_ampl, 
+			"separable", TRUE,
+			"precision", gaussblur->precision,
+			NULL ) )
+			return( -1 ); 
 
 #ifdef DEBUG
-	printf( "gaussblur: blurring with:\n" ); 
-	vips_matrixprint( t[0], NULL ); 
+		printf( "gaussblur: blurring with:\n" ); 
+		vips_matrixprint( t[0], NULL ); 
 #endif /*DEBUG*/
 
-	g_info( "gaussblur mask width %d", t[0]->Xsize );
+		g_info( "gaussblur mask width %d", t[0]->Xsize );
 
-	if( vips_convsep( gaussblur->in, &t[1], t[0], 
-		"precision", gaussblur->precision,
-		NULL ) )
-		return( -1 );
+		if( vips_convsep( gaussblur->in, &t[1], t[0], 
+			"precision", gaussblur->precision,
+			NULL ) )
+			return( -1 );
+	}
 
 	g_object_set( object, "out", vips_image_new(), NULL ); 
 
@@ -132,7 +145,7 @@ vips_gaussblur_class_init( VipsGaussblurClass *class )
 		_( "Sigma of Gaussian" ),
 		VIPS_ARGUMENT_REQUIRED_INPUT,
 		G_STRUCT_OFFSET( VipsGaussblur, sigma ),
-		0.01, 1000, 1.5 );
+		0.0, 1000, 1.5 );
 
 	VIPS_ARG_DOUBLE( class, "min_ampl", 3, 
 		_( "Minimum amplitude" ), 

libvips/foreign/pdfload.c

@@ -16,6 +16,8 @@
  * 	- reopen the input if we minimised too early
  * 11/3/20
  * 	- move on top of VipsSource
+ * 21/9/20
+ * 	- allow dpi and scale to both be set [le0daniel]
  */
 
 /*
@@ -109,10 +111,14 @@ typedef struct _VipsForeignLoadPdf {
 	 */
 	double dpi;
 
-	/* Calculate this from DPI. At 72 DPI, we render 1:1 with cairo.
+	/* Scale by this factor.
 	 */
 	double scale;
 
+	/* The total scale factor we render with.
+	 */
+	double total_scale;
+
 	/* Background colour.
 	 */
 	VipsArrayDouble *background;
@@ -170,8 +176,7 @@ vips_foreign_load_pdf_build( VipsObject *object )
 
 	GError *error = NULL;
 
-	if( !vips_object_argument_isset( object, "scale" ) )
-		pdf->scale = pdf->dpi / 72.0;
+	pdf->total_scale = pdf->scale * pdf->dpi / 72.0;
 
 	pdf->stream = vips_g_input_stream_new_from_source( pdf->source );
 	if( !(pdf->doc = poppler_document_new_from_stream( pdf->stream, 
@@ -338,8 +343,8 @@ vips_foreign_load_pdf_header( VipsForeignLoad *load )
 		 * does round to nearest. Without this, things like
 		 * shrink-on-load will break.
 		 */
-		pdf->pages[i].width = VIPS_RINT( width * pdf->scale );
-		pdf->pages[i].height = VIPS_RINT( height * pdf->scale );
+		pdf->pages[i].width = VIPS_RINT( width * pdf->total_scale );
+		pdf->pages[i].height = VIPS_RINT( height * pdf->total_scale );
 
 		if( pdf->pages[i].width > pdf->image.width )
 			pdf->image.width = pdf->pages[i].width;
@@ -421,10 +426,10 @@ vips_foreign_load_pdf_generate( VipsRegion *or,
 		cr = cairo_create( surface );
 		cairo_surface_destroy( surface );
 
-		cairo_scale( cr, pdf->scale, pdf->scale );
+		cairo_scale( cr, pdf->total_scale, pdf->total_scale );
 		cairo_translate( cr, 
-			(pdf->pages[i].left - rect.left) / pdf->scale, 
-			(pdf->pages[i].top - rect.top) / pdf->scale );
+			(pdf->pages[i].left - rect.left) / pdf->total_scale, 
+			(pdf->pages[i].top - rect.top) / pdf->total_scale );
 
 		/* poppler is single-threaded, but we don't need to lock since 
 		 * we're running inside a non-threaded tilecache.
@@ -862,9 +867,8 @@ vips_foreign_load_pdf_is_a( const char *filename )
  * left. Set to -1 to mean "until the end of the document". Use vips_grid() 
  * to change page layout.
  *
- * Use @dpi to set the rendering resolution. The default is 72. Alternatively,
- * you can scale the rendering from the default 1 point == 1 pixel by 
- * setting @scale.
+ * Use @dpi to set the rendering resolution. The default is 72. Additionally,
+ * you can scale by setting @scale. If you set both, they combine.
  *
  * Use @background to set the background RGBA colour. The default is 255 
  * (solid white), use eg. 0 for a transparent background.

libvips/resample/thumbnail.c

@@ -736,24 +736,6 @@ vips_thumbnail_build( VipsObject *object )
 		return( -1 ); 
 	in = t[2];
 
-	/* If there's an alpha, we have to premultiply before shrinking. See
-	 * https://github.com/libvips/libvips/issues/291
-	 */
-	have_premultiplied = FALSE;
-	if( vips_image_hasalpha( in ) ) { 
-		g_info( "premultiplying alpha" ); 
-		if( vips_premultiply( in, &t[3], NULL ) ) 
-			return( -1 );
-		have_premultiplied = TRUE;
-
-		/* vips_premultiply() makes a float image. When we
-		 * vips_unpremultiply() below, we need to cast back to the
-		 * pre-premultiply format.
-		 */
-		unpremultiplied_format = in->BandFmt;
-		in = t[3];
-	}
-
 	/* Shrink to preshrunk_page_height, so we work for multi-page images.
 	 */
 	vips_thumbnail_calculate_shrink( thumbnail, 
@@ -771,6 +753,26 @@ vips_thumbnail_build( VipsObject *object )
 		vshrink = (double) in->Ysize / target_image_height;
 	}
 
+	/* If there's an alpha, we have to premultiply before shrinking. See
+	 * https://github.com/libvips/libvips/issues/291
+	 */
+	have_premultiplied = FALSE;
+	if( vips_image_hasalpha( in ) && 
+	 	hshrink != 1.0 &&
+		vshrink != 1.0  ) { 
+		g_info( "premultiplying alpha" ); 
+		if( vips_premultiply( in, &t[3], NULL ) ) 
+			return( -1 );
+		have_premultiplied = TRUE;
+
+		/* vips_premultiply() makes a float image. When we
+		 * vips_unpremultiply() below, we need to cast back to the
+		 * pre-premultiply format.
+		 */
+		unpremultiplied_format = in->BandFmt;
+		in = t[3];
+	}
+
 	if( vips_resize( in, &t[4], 1.0 / hshrink, 
 		"vscale", 1.0 / vshrink, 
 		NULL ) )