"Willem Van der Voort" wrote in
:
"RustYŠ" schreef in bericht
. 163...
This file was encoded with the new yEnc encoding scheme, designed to
save bandwidth by dramatically reducing the 30%+ overhead incurred by
UU and Base64.
For more info, see http://www.yenc.org/
This file was NOT encoded with the new yEnc.... Result 64Kb
JPG is a 'lossy' image compression scheme. yEnc is a lossless file
transmission protocol. They are not the same. Tranmission of binary
files on Usenet requires encoding as the Usenet protocol - NNTP - does not
allow for the straight transmission of 8 bit data, instead requiring it be
recoded to a 7 bit ASCII format using a method called 'MIME'. This
expands the size of the ~transmitted~ file by a rather hefty amount. Once
it is decoded on the receiving computer it is once again the original file
as sent by the poster.
yEnc is a different, more efficient form of transmission encoding that,
like MIME, has no effect on the data in the original file. What it does
is use bandwidth more effectively by using fewer bytes. This may not be
so noticeable with small files like image JPGs, but it certainly helps
with larger files such as video and disc images, legal or otherwise.
Rusty's example showed how much transmission bandwidth can be saved for
the same ~identical~ JPG image using MIME vs yEnc.
Willem's example showed how easily you can corrupt a beautiful image with
JPG artifacts by over-compressing it.
I use the free XNews newsreader to follow this group. It handles yEnc
transparently with no problems. I have used yProxy in the past with
similar trouble free results. The main complaint I hear about yEnc is the
MS Outlook Express does not support it 'out of the box', and a lot of
folks still use OE for newsreading.
A sizeable percentage of this group have requested that others please use
MIME rather than yEnc when posting, most of the regulars have agreed to do
this out of courtesy. I find it a little annoying when a new poster gets
flamed immediately for posting in yEnc rather than being asked politely if
they will use MIME - it is just a bit rude to blow someone arse over
teacups out the door when they arrive with new images to share,
dontchathink?
My two cents, and I expect change!
Bob ^,,^