/* Open an image, returning the best version of that image for thumbnailing. * * libjpeg supports fast shrink-on-read, so if we have a JPEG, we can ask * VIPS to load a lower resolution version. */ static VipsImage * thumbnail_open( VipsObject *process, const char *filename ) { const char *loader; VipsImage *im; vips_info( "vipsthumbnail", "thumbnailing %s", filename ); if( linear_processing ) vips_info( "vipsthumbnail", "linear mode" ); if( !(loader = vips_foreign_find_load( filename )) ) return( NULL ); vips_info( "vipsthumbnail", "selected loader is %s", loader ); if( strcmp( loader, "VipsForeignLoadJpegFile" ) == 0 ) { int jpegshrink; /* This will just read in the header and is quick. */ if( !(im = vips_image_new_from_file( filename, NULL )) ) return( NULL ); jpegshrink = thumbnail_find_jpegshrink( im ); g_object_unref( im ); vips_info( "vipsthumbnail", "loading jpeg with factor %d pre-shrink", jpegshrink ); if( !(im = vips_image_new_from_file( filename, "access", VIPS_ACCESS_SEQUENTIAL, "shrink", jpegshrink, NULL )) ) return( NULL ); } else { /* All other formats. */ if( !(im = vips_image_new_from_file( filename, "access", VIPS_ACCESS_SEQUENTIAL, NULL )) ) return( NULL ); } vips_object_local( process, im ); return( im ); }
/* Try to read an embedded thumbnail. */ static VipsImage * thumbnail_get_thumbnail( VipsImage *im ) { void *ptr; size_t size; VipsImage *thumb; double residual; int jpegshrink; if( !vips_image_get_typeof( im, THUMBNAIL ) || vips_image_get_blob( im, THUMBNAIL, &ptr, &size ) || vips_jpegload_buffer( ptr, size, &thumb, NULL ) ) { vips_info( "vipsthumbnail", "no jpeg thumbnail" ); return( NULL ); } calculate_shrink( thumb->Xsize, thumb->Ysize, &residual ); if( residual > 1.0 ) { vips_info( "vipsthumbnail", "jpeg thumbnail too small" ); g_object_unref( thumb ); return( NULL ); } /* Reload with the correct downshrink. */ jpegshrink = thumbnail_find_jpegshrink( thumb ); vips_info( "vipsthumbnail", "loading jpeg thumbnail with factor %d pre-shrink", jpegshrink ); g_object_unref( thumb ); if( vips_jpegload_buffer( ptr, size, &thumb, "shrink", jpegshrink, NULL ) ) { vips_info( "vipsthumbnail", "jpeg thumbnail reload failed" ); return( NULL ); } vips_info( "vipsthumbnail", "using %dx%d jpeg thumbnail", thumb->Xsize, thumb->Ysize ); return( thumb ); }
/* Open an image, returning the best version of that image for thumbnailing. * * libjpeg supports fast shrink-on-read, so if we have a JPEG, we can ask * VIPS to load a lower resolution version. */ static VipsImage * thumbnail_open( VipsObject *process, const char *filename ) { const char *loader; VipsImage *im; vips_info( "vipsthumbnail", "thumbnailing %s", filename ); if( linear_processing ) vips_info( "vipsthumbnail", "linear mode" ); if( !(loader = vips_foreign_find_load( filename )) ) return( NULL ); vips_info( "vipsthumbnail", "selected loader is %s", loader ); if( strcmp( loader, "VipsForeignLoadJpegFile" ) == 0 ) { int jpegshrink; /* This will just read in the header and is quick. */ if( !(im = vips_image_new_from_file( filename, NULL )) ) return( NULL ); jpegshrink = thumbnail_find_jpegshrink( im ); g_object_unref( im ); vips_info( "vipsthumbnail", "loading jpeg with factor %d pre-shrink", jpegshrink ); /* We can't use UNBUFERRED safely on very-many-core systems. */ if( !(im = vips_image_new_from_file( filename, "access", VIPS_ACCESS_SEQUENTIAL, "shrink", jpegshrink, NULL )) ) return( NULL ); } else if( strcmp( loader, "VipsForeignLoadPdfFile" ) == 0 || strcmp( loader, "VipsForeignLoadSvgFile" ) == 0 ) { double shrink; /* This will just read in the header and is quick. */ if( !(im = vips_image_new_from_file( filename, NULL )) ) return( NULL ); shrink = calculate_shrink( im ); g_object_unref( im ); vips_info( "vipsthumbnail", "loading PDF/SVG with factor %g pre-shrink", shrink ); /* We can't use UNBUFERRED safely on very-many-core systems. */ if( !(im = vips_image_new_from_file( filename, "access", VIPS_ACCESS_SEQUENTIAL, "scale", 1.0 / shrink, NULL )) ) return( NULL ); } else if( strcmp( loader, "VipsForeignLoadWebpFile" ) == 0 ) { double shrink; /* This will just read in the header and is quick. */ if( !(im = vips_image_new_from_file( filename, NULL )) ) return( NULL ); shrink = calculate_shrink( im ); g_object_unref( im ); vips_info( "vipsthumbnail", "loading webp with factor %g pre-shrink", shrink ); /* We can't use UNBUFERRED safely on very-many-core systems. */ if( !(im = vips_image_new_from_file( filename, "access", VIPS_ACCESS_SEQUENTIAL, "shrink", (int) shrink, NULL )) ) return( NULL ); } else { /* All other formats. We can't use UNBUFERRED safely on * very-many-core systems. */ if( !(im = vips_image_new_from_file( filename, "access", VIPS_ACCESS_SEQUENTIAL, NULL )) ) return( NULL ); } vips_object_local( process, im ); return( im ); }
/* Open an image, returning the best version of that image for thumbnailing. * * jpegs can have embedded thumbnails ... use that if it's large enough. * * libjpeg supports fast shrink-on-read, so if we have a JPEG, we can ask * VIPS to load a lower resolution version. */ static VipsImage * thumbnail_open( VipsObject *process, const char *filename ) { const char *loader; VipsImage *im; vips_info( "vipsthumbnail", "thumbnailing %s", filename ); if( linear_processing ) vips_info( "vipsthumbnail", "linear mode" ); if( !(loader = vips_foreign_find_load( filename )) ) return( NULL ); vips_info( "vipsthumbnail", "selected loader is %s", loader ); if( strcmp( loader, "VipsForeignLoadJpegFile" ) == 0 ) { VipsImage *thumb; /* This will just read in the header and is quick. */ if( !(im = vips_image_new_from_file( filename )) ) return( NULL ); /* Try to read an embedded thumbnail. If we find one, use that * instead. */ if( (thumb = thumbnail_get_thumbnail( im )) ) { /* @thumb has not been fully decoded yet ... * we must not close @im * until we're done with @thumb. */ vips_object_local( VIPS_OBJECT( thumb ), im ); im = thumb; } else { int jpegshrink; vips_info( "vipsthumbnail", "processing main jpeg image" ); jpegshrink = thumbnail_find_jpegshrink( im ); g_object_unref( im ); vips_info( "vipsthumbnail", "loading jpeg with factor %d pre-shrink", jpegshrink ); if( vips_foreign_load( filename, &im, "access", VIPS_ACCESS_SEQUENTIAL, "shrink", jpegshrink, NULL ) ) return( NULL ); } } else { /* All other formats. */ if( vips_foreign_load( filename, &im, "access", VIPS_ACCESS_SEQUENTIAL, NULL ) ) return( NULL ); } vips_object_local( process, im ); return( im ); }