libjpeg-turbo: Upgrade to 1.5.1
The changes from 1.4.2 to 1.5.1 include
a big amount of fixes and huge performance improvements.
As highlights there is a full ARM 64-bit (ARMv8) NEON SIMD
implementation which improves compression of full-color JPEGs
by about 2-2.5x on average on Cortex-A53 and Cortex-A57 cores.
Also SIMD acceleration for Huffman encoding on NEON-capable
ARM 32-bit and 64-bit platforms was added.
Performance on x86/x86_64 was also improved by
adding better optimized SSE2 routines.
For the full changelog, please see the ChangeLog.md
file.
Partial decoding optimizations, the security fix
to adress b/27494207 and the fix for the AARCH64
conformance issueare present in the release.
The README.android file was edited to reflect this.
The configuration files were regenerated
and all Android specific changes were applied.
BUG:28268702
Change-Id: I538291d894df1da01d3f733771647df1fb61ec42
Signed-off-by: Alex Naidis <alex.naidis@linux.com>
diff --git a/cjpeg.1 b/cjpeg.1
index e338c80..d1dc304 100644
--- a/cjpeg.1
+++ b/cjpeg.1
@@ -1,4 +1,4 @@
-.TH CJPEG 1 "21 November 2014"
+.TH CJPEG 1 "17 February 2016"
.SH NAME
cjpeg \- compress an image file to a JPEG file
.SH SYNOPSIS
@@ -85,8 +85,8 @@
and the closer the output image will be to the original input. Normally you
want to use the lowest quality setting (smallest file) that decompresses into
something visually indistinguishable from the original image. For this
-purpose the quality setting should be between 50 and 95; the default of 75 is
-often about right. If you see defects at
+purpose the quality setting should generally be between 50 and 95 (the default
+is 75) for photographic images. If you see defects at
.B \-quality
75, then go up 5 or 10 counts at a time until you are happy with the output
image. (The optimal setting will vary from one image to another.)
@@ -94,11 +94,10 @@
.B \-quality
100 will generate a quantization table of all 1's, minimizing loss in the
quantization step (but there is still information loss in subsampling, as well
-as roundoff error). This setting is mainly of interest for experimental
-purposes. Quality values above about 95 are
-.B not
-recommended for normal use; the compressed file size goes up dramatically for
-hardly any gain in output image quality.
+as roundoff error.) For most images, specifying a quality value above
+about 95 will increase the size of the compressed file dramatically, and while
+the quality gain from these higher quality values is measurable (using metrics
+such as PSNR or SSIM), it is rarely perceivable by human vision.
.PP
In the other direction, quality values below 50 will produce very small files
of low image quality. Settings around 5 to 10 might be useful in preparing an
@@ -338,11 +337,11 @@
This file was modified by The libjpeg-turbo Project to include only information
relevant to libjpeg-turbo, to wordsmith certain sections, and to describe
features not present in libjpeg.
-.SH BUGS
+.SH ISSUES
Support for GIF input files was removed in cjpeg v6b due to concerns over
the Unisys LZW patent. Although this patent expired in 2006, cjpeg still
lacks GIF support, for these historical reasons. (Conversion of GIF files to
-JPEG is usually a bad idea anyway.)
+JPEG is usually a bad idea anyway, since GIF is a 256-color format.)
.PP
Not all variants of BMP and Targa file formats are supported.
.PP