From efadb5dc422c7395f24fbfdf97350f85a2eebaf8 Mon Sep 17 00:00:00 2001 From: John Cupitt Date: Sat, 27 Apr 2019 22:33:20 +0100 Subject: [PATCH] fix thumbnail shrink-on-load we had the alignment check in the wrong place --- libvips/iofuncs/header.c | 5 +++-- libvips/resample/thumbnail.c | 24 ++++++++++++------------ 2 files changed, 15 insertions(+), 14 deletions(-) diff --git a/libvips/iofuncs/header.c b/libvips/iofuncs/header.c index fe6a3e30..c5cb2814 100644 --- a/libvips/iofuncs/header.c +++ b/libvips/iofuncs/header.c @@ -782,7 +782,8 @@ vips_image_get_offset( const VipsImage *image ) * vips_image_get_page_height: (method) * @image: image to get from * - * Multi-page images can have a page height. Fetch it, and sanity check it. + * Multi-page images can have a page height. Fetch it, and sanity check it. If + * page-height is not set, it defaults to the image height. * * Returns: the page height. */ @@ -791,7 +792,7 @@ vips_image_get_page_height( VipsImage *image ) { int page_height; - page_height = 0; + page_height = image->Ysize; if( vips_image_get_typeof( image, VIPS_META_PAGE_HEIGHT ) && vips_image_get_int( image, VIPS_META_PAGE_HEIGHT, &page_height ) ) diff --git a/libvips/resample/thumbnail.c b/libvips/resample/thumbnail.c index 494f8f25..e5a27e36 100644 --- a/libvips/resample/thumbnail.c +++ b/libvips/resample/thumbnail.c @@ -355,18 +355,6 @@ vips_thumbnail_calculate_shrink( VipsThumbnail *thumbnail, *hshrink = VIPS_MAX( 1, *hshrink ); *vshrink = VIPS_MAX( 1, *vshrink ); } - - /* In toilet-roll mode, we must adjust vshrink so that we exactly hit - * page_height or we'll have pixels straddling pixel boundaries. - */ - if( thumbnail->input_height > thumbnail->page_height ) { - int target_page_height = VIPS_RINT( input_height / *vshrink ); - int target_image_height = target_page_height * - thumbnail->n_pages; - - *vshrink = (double) input_height * thumbnail->n_pages / - target_image_height; - } } /* Just the common part of the shrink: the bit by which both axes must be @@ -670,6 +658,18 @@ vips_thumbnail_build( VipsObject *object ) vips_thumbnail_calculate_shrink( thumbnail, in->Xsize, thumbnail->page_height, &hshrink, &vshrink ); + /* In toilet-roll mode, we must adjust vshrink so that we exactly hit + * page_height or we'll have pixels straddling pixel boundaries. + */ + if( in->Ysize > thumbnail->page_height ) { + int target_page_height = VIPS_RINT( + thumbnail->page_height / vshrink ); + int target_image_height = target_page_height * + thumbnail->n_pages; + + vshrink = (double) in->Ysize / target_image_height; + } + if( vips_resize( in, &t[4], 1.0 / hshrink, "vscale", 1.0 / vshrink, NULL ) )