From: Jean-Francois Moine <moinejf@free.fr>
To: Hans de Goede <hdegoede@redhat.com>
Cc: linux-media@vger.kernel.org
Subject: [PATCH] tinyjpeg: Better luminance quantization table for Pixart JPEG
Date: Fri, 23 Mar 2012 20:19:45 +0100 [thread overview]
Message-ID: <20120323201945.39f26d98@tele> (raw)
An other luminance quantization table gives a better quality to the
Pixart images created by the webcams handled by the gspca drivers
pac7302 and pac7311 (pixel format 'PJPG').
Tests have been done with 5 different pac7302 webcams. The marker was
always 0x44.
Signed-off-by: Jean-François Moine <moinejf@free.fr>
diff --git a/lib/libv4lconvert/tinyjpeg.c b/lib/libv4lconvert/tinyjpeg.c
index e308f63..687e69c 100644
--- a/lib/libv4lconvert/tinyjpeg.c
+++ b/lib/libv4lconvert/tinyjpeg.c
@@ -206,14 +206,14 @@ static const unsigned char val_ac_chrominance[] = {
};
const unsigned char pixart_quantization[][64] = { {
- 0x07, 0x07, 0x08, 0x0a, 0x09, 0x07, 0x0d, 0x0b,
- 0x0c, 0x0d, 0x11, 0x10, 0x0f, 0x12, 0x17, 0x27,
- 0x1a, 0x18, 0x16, 0x16, 0x18, 0x31, 0x23, 0x25,
- 0x1d, 0x28, 0x3a, 0x33, 0x3d, 0x3c, 0x39, 0x33,
- 0x38, 0x37, 0x40, 0x48, 0x5c, 0x4e, 0x40, 0x44,
- 0x57, 0x45, 0x37, 0x38, 0x50, 0x6d, 0x51, 0x57,
- 0x5f, 0x62, 0x67, 0x68, 0x67, 0x3e, 0x4d, 0x71,
- 0x79, 0x70, 0x64, 0x78, 0x5c, 0x65, 0x67, 0x63,
+ 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x10, 0x10,
+ 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
+ 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
+ 0x10, 0x10, 0x10, 0x10, 0x20, 0x20, 0x20, 0x20,
+ 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+ 0x20, 0x20, 0x20, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
+ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,
},
{
0x11, 0x12, 0x12, 0x18, 0x15, 0x18, 0x2f, 0x1a,
--
Ken ar c'hentañ | ** Breizh ha Linux atav! **
Jef | http://moinejf.free.fr/
next reply other threads:[~2012-03-23 19:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-23 19:19 Jean-Francois Moine [this message]
2012-04-07 15:01 ` [PATCH] tinyjpeg: Better luminance quantization table for Pixart JPEG Hans de Goede
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120323201945.39f26d98@tele \
--to=moinejf@free.fr \
--cc=hdegoede@redhat.com \
--cc=linux-media@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.