update

[l4.git] / l4 / pkg / libjpeg / lib / contrib / libjpeg.txt

diff --git a/l4/pkg/libjpeg/lib/contrib/libjpeg.txt b/l4/pkg/libjpeg/lib/contrib/libjpeg.txt
index e5a85c0e3e87aca7374e0caee0fb42555ef2a564..2d98e22fc41349dff652dd38d209b6cd17e78a35 100644 (file)
--- a/l4/pkg/libjpeg/lib/contrib/libjpeg.txt
+++ b/l4/pkg/libjpeg/lib/contrib/libjpeg.txt
@@ -1,6 +1,6 @@
 USING THE IJG JPEG LIBRARY
 
-Copyright (C) 1994-2009, Thomas G. Lane, Guido Vollbeding.
+Copyright (C) 1994-2010, Thomas G. Lane, Guido Vollbeding.
 This file is part of the Independent JPEG Group's software.
 For conditions of distribution and use, see the accompanying README file.
 
@@ -876,6 +876,18 @@ jpeg_simple_progression (j_compress_ptr cinfo)
 
 Compression parameters (cinfo fields) include:
 
+int block_size
+       Set DCT block size.  All N from 1 to 16 are possible.
+       Default is 8 (baseline format).
+       Larger values produce higher compression,
+       smaller values produce higher quality.
+       An exact DCT stage is possible with 1 or 2.
+       With the default quality of 75 and default Luminance qtable
+       the DCT+Quantization stage is lossless for value 1.
+       Note that values other than 8 require a SmartScale capable decoder,
+       introduced with IJG JPEG 8.  Setting the block_size parameter for
+       compression works with version 8c and later.
+
 J_DCT_METHOD dct_method
        Selects the algorithm used for the DCT step.  Choices are:
                JDCT_ISLOW: slow but accurate integer algorithm
@@ -895,8 +907,10 @@ J_DCT_METHOD dct_method
 unsigned int scale_num, scale_denom
        Scale the image by the fraction scale_num/scale_denom.  Default is
        1/1, or no scaling.  Currently, the supported scaling ratios are
-       8/N with all N from 1 to 16.  (The library design allows for arbitrary
-       scaling ratios but this is not likely to be implemented any time soon.)
+       M/N with all N from 1 to 16, where M is the destination DCT size,
+       which is 8 by default (see block_size parameter above).
+       (The library design allows for arbitrary scaling ratios but this
+       is not likely to be implemented any time soon.)
 
 J_COLOR_SPACE jpeg_color_space
 int num_components