Home > Archive > Compression > May 2004 > JPEG decompression
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
| Author |
JPEG decompression
|
|
|
| hi,
I am viewing an image(a rectangle with some pattern in it) using the
Independant jpeg group's code for decompresison.
At the borders(outside) of the rectangle some dusts are appearing.
Could anyone tell me why they are appearing and what can we do to
remove it.
plz someone help me in that.
regards,
Anil
| |
| Daniel Haude 2004-05-21, 7:30 am |
| On 20 May 2004 22:51:27 -0700,
Anil <anil.kadimisetty@patni.com> wrote
in Msg. <a20a2523.0405202151.274d0305@posting.google.com>
> I am viewing an image(a rectangle with some pattern in it) using the
> Independant jpeg group's code for decompresison.
> At the borders(outside) of the rectangle some dusts are appearing.
Typical JPEG compression artifact.
> Could anyone tell me why they are appearing and what can we do to
> remove it.
Nothing.
JPEG is not the compression algorithm of choice when it comes to
geometric pictures with even colors and straight lines in them, but of
course you know that since you have read the JPEG docs. For this type of
image use, for instance, PNG.
--Daniel
--
"With me is nothing wrong! And with you?" (from r.a.m.p)
| |
| Flavius Vespasianus 2004-05-21, 11:30 am |
| anil.kadimisetty@patni.com (Anil) wrote in
news:a20a2523.0405202151.274d0305@posting.google.com:
> hi,
>
> I am viewing an image(a rectangle with some pattern in it) using the
> Independant jpeg group's code for decompresison.
> At the borders(outside) of the rectangle some dusts are appearing.
> Could anyone tell me why they are appearing and what can we do to
> remove it.
You're never going to get it perfect, especially if the image has been
compressed with artifacts. However, one thing to try is to make sure the
decompressing software is not filtering the output. It may be trying to
smooth out areas where you want a jagged edge.
| |
|
| Flavius Vespasianus <nl@nl.com> wrote in message news:<1gorc.24115$KE6.13052@newsread3.news.atl.earthlink.net>...
> anil.kadimisetty@patni.com (Anil) wrote in
> news:a20a2523.0405202151.274d0305@posting.google.com:
>
>
> You're never going to get it perfect, especially if the image has been
> compressed with artifacts. However, one thing to try is to make sure the
> decompressing software is not filtering the output. It may be trying to
> smooth out areas where you want a jagged edge.
Hi,
Could you tell me why i can never get it perfect?
Actually when i made a change in the huffman decoding initialisation
part,
(changed the entropy->bitstate value form `0` to `1`) then i got a
rectangle with smooth edges. But here i do not know ho w but the area
of the rectangle was seen to increase. Could anyone explain what that
means?
|
|
|
|
|