From 51dbf607dddbfcba391e6811a248a6082397f8c9 Mon Sep 17 00:00:00 2001 From: John Cupitt Date: Wed, 19 Dec 2018 14:52:33 +0000 Subject: [PATCH] add skip-blanks option to dzsave Skip-blanks was a feature of google layout. This patch makes it into an option you can control which defaults on in gm mode. See https://github.com/libvips/libvips/issues/1185 --- ChangeLog | 1 + libvips/foreign/dzsave.c | 38 ++++++++++++++++++++++++++++---------- 2 files changed, 29 insertions(+), 10 deletions(-) diff --git a/ChangeLog b/ChangeLog index a6db28c2..ceca3096 100644 --- a/ChangeLog +++ b/ChangeLog @@ -12,6 +12,7 @@ - don't stop composite on first non-transparent image [felixbuenemann, GDmac] - add vips_rect_overlapsrect() - composite is much faster at positioning subimages +- dzsave has a new skip_blanks option 21/11/18 started 8.7.3 - fix infinite loop for autofit with non-scaleable font diff --git a/libvips/foreign/dzsave.c b/libvips/foreign/dzsave.c index 54f97a1d..889c4e0a 100644 --- a/libvips/foreign/dzsave.c +++ b/libvips/foreign/dzsave.c @@ -76,6 +76,8 @@ * 24/11/17 * - output overlap-only tiles on edges for better deepzoom spec * compliance + * 19/12/18 + * - add @skip_blanks */ /* @@ -448,6 +450,7 @@ struct _VipsForeignSaveDz { VipsForeignDzContainer container; int compression; VipsRegionShrink region_shrink; + gboolean skip_blanks; /* Tile and overlap geometry. The members above are the parameters we * accept, this next set are the derived values which are actually @@ -1166,10 +1169,7 @@ strip_work( VipsThreadState *state, void *a ) state->pos.width, state->pos.height, NULL ) ) return( -1 ); - /* If we are writing a google map pyramid and the tile is equal to the - * background, don't save. The viewer will display blank.png for us. - */ - if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE && + if( dz->skip_blanks && tile_equal( x, dz->ink ) ) { g_object_unref( x ); @@ -1631,6 +1631,12 @@ vips_foreign_save_dz_build( VipsObject *object ) dz->tile_size = 256; } + /* skip_blanks defaults TRUE in google mode. + */ + if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE && + !vips_object_argument_isset( object, "skip_blanks" ) ) + dz->skip_blanks = TRUE; + /* Our tile layout. */ if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_DZ ) { @@ -1650,8 +1656,7 @@ vips_foreign_save_dz_build( VipsObject *object ) /* Default to white background. vips_foreign_save_init() defaults to * black. */ - if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE && - !vips_object_argument_isset( object, "background" ) ) { + if( !vips_object_argument_isset( object, "background" ) ) { VipsArrayDouble *background; /* Using g_object_set() to set an input param in build will @@ -1690,9 +1695,9 @@ vips_foreign_save_dz_build( VipsObject *object ) save->ready = z; } - /* We use ink in google mode to check for blank tiles. + /* We use ink to check for blank tiles. */ - if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE ) { + if( dz->skip_blanks ) { if( !(dz->ink = vips__vector_to_ink( class->nickname, save->ready, VIPS_AREA( save->background )->data, NULL, @@ -2105,6 +2110,13 @@ vips_foreign_save_dz_class_init( VipsForeignSaveDzClass *class ) G_STRUCT_OFFSET( VipsForeignSaveDz, region_shrink ), VIPS_TYPE_REGION_SHRINK, VIPS_REGION_SHRINK_MEAN ); + VIPS_ARG_BOOL( class, "skip_blanks", 19, + _( "Skip blanks" ), + _( "Skip tiles which are nearly equal to the background" ), + VIPS_ARGUMENT_OPTIONAL_INPUT, + G_STRUCT_OFFSET( VipsForeignSaveDz, skip_blanks ), + FALSE ); + /* How annoying. We stupidly had these in earlier versions. */ @@ -2340,7 +2352,8 @@ vips_foreign_save_dz_buffer_init( VipsForeignSaveDzBuffer *buffer ) * * @container: #VipsForeignDzContainer set container type * * @properties: %gboolean write a properties file * * @compression: %gint zip deflate compression level - * * @shrink_region: #VipsRegionShrink How to shrink each 2x2 region. + * * @region_shrink: #VipsRegionShrink How to shrink each 2x2 region + * * @skip_blanks: %gboolean Skip tiles which are equal to the background * * Save an image as a set of tiles at various resolutions. By default dzsave * uses DeepZoom layout -- use @layout to pick other conventions. @@ -2387,6 +2400,10 @@ vips_foreign_save_dz_buffer_init( VipsForeignSaveDzBuffer *buffer ) * You can use @region_shrink to control the method for shrinking each 2x2 * region. This defaults to using the average of the 4 input pixels but you can * also use the median in cases where you want to preserve the range of values. + * + * If you set @skip_blanks, tiles which are almost equal to the background are + * skipped. This can save a lot of space for some image types. This option + * defaults %TRUE in Google layout mode. * * See also: vips_tiffsave(). * @@ -2426,7 +2443,8 @@ vips_dzsave( VipsImage *in, const char *name, ... ) * * @container: #VipsForeignDzContainer set container type * * @properties: %gboolean write a properties file * * @compression: %gint zip deflate compression level - * * @shrink_region: #VipsRegionShrink How to shrink each 2x2 region. + * * @region_shrink: #VipsRegionShrink How to shrink each 2x2 region. + * * @skip_blanks: %gboolean Skip tiles which are equal to the background * * As vips_dzsave(), but save to a memory buffer. *