[gegl] jpg-load: Use slightly more accurate float DCT during load (Bug #741776)

[Mukund Sivaraman <muks src gnome org>]

commit 433d699eefe0d052e9b6ecb4eb81e4e4c53bed75
Author: Mukund Sivaraman <muks banu com>
Date:   Sat Dec 20 16:20:42 2014 +0530

    jpg-load: Use slightly more accurate float DCT during load (Bug #741776)

 operations/external/jpg-load.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/operations/external/jpg-load.c b/operations/external/jpg-load.c
index 8cbaca6..2fa567c 100644
--- a/operations/external/jpg-load.c
+++ b/operations/external/jpg-load.c
@@ -228,6 +228,13 @@ gegl_jpg_load_buffer_import_jpg (GeglBuffer  *gegl_buffer,
   gio_source_enable(&cinfo, &src, &gio_source);
 
   (void) jpeg_read_header (&cinfo, TRUE);
+
+  /* This is the most accurate method and could be the fastest too. But
+   * the results may vary on different platforms due to different
+   * rounding behavior and precision.
+   */
+  cinfo.dct_method = JDCT_FLOAT;
+
   (void) jpeg_start_decompress (&cinfo);
 
   format = babl_from_jpeg_colorspace(cinfo.out_color_space);