Fax2Email image quality?

'Fax to Email' and 'Email to Fax' services
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trk
Posts: 59
Joined: Fri Feb 12, 2010 12:38 am
Location: Brisbane

Fax2Email image quality?

Post by trk » Thu Feb 18, 2010 12:02 pm

Hi all,

Recently signed up for Fax2Email (and, fwiw, Email2Fax) so I could send test faxes to myself from our workshop which has had ongoing dramas with 64bit OS and old fax software (EDIT: I should add that we now have NEW fax software, which is Joyfax - a Winfax-esque program)

I've since got the workshop fax working, and have been sending and receiving faxes from suppliers and clients ok. The reason we use faxes is for handwritten notations and signed authorisations, so we frequently end up receiving the same fax we sent (thats been printed, signed, and returned - Im sure you can imagine the quality loss)

One thing I've noticed is that faxes send to Exetels Fax2Email end up with a lot of noise through them. More so than sending to a "normal" PSTN fax machine.

Is this related to VOIP in any way? Or a compatability issue between our modem and theirs?

If someone else who uses the Fax2Email service is able to confirm they get clear faxes (well... as clear as faxes get) I'll see if theres some init string or driver changes I can do to improve our ends fax quality, but if its just the nature of the beast I'm happy to put up with it. Unless the fax is using size 8pt or smaller font the noise doesnt render it illegible anyway. And for $1/month including a DID number its hardly breaking the bank :P
Last edited by trk on Thu Feb 18, 2010 12:37 pm, edited 1 time in total.

trk
Posts: 59
Joined: Fri Feb 12, 2010 12:38 am
Location: Brisbane

Re: Fax2Email image quality?

Post by trk » Thu Feb 18, 2010 12:29 pm

I just tried sending an 8 page fax (part of a camera manual) so I could provide a screen grab of the noise, and it failed. Exetel (well, hylaFAX) quite nicely attached a log file to the emailed PDF which contains a lot of useful information, though it doesnt really answer my original question of "is it us or them?" :P Other fax machines on PSTN have worked today, so I'm assuming its not just us?

Log file snippet here:
Feb 18 12:06:34.25: [14976]: RECV: begin page
Feb 18 12:06:36.35: [14976]: RECV/CQ: Invalid WhiteTable code word, row 24, x 6
Feb 18 12:06:36.35: [14976]: RECV/CQ: Bad 1D pixel count, row 24, got 6, expected 1728
Feb 18 12:06:36.55: [14976]: RECV/CQ: Invalid WhiteTable code word, row 25, x 142
Feb 18 12:06:36.55: [14976]: RECV/CQ: Bad 1D pixel count, row 25, got 142, expected 1728
Feb 18 12:06:36.55: [14976]: RECV/CQ: Bad 1D pixel count, row 26, got 3203, expected 1728
Feb 18 12:06:36.55: [14976]: RECV/CQ: Bad 1D pixel count, row 27, got 30, expected 1728
Feb 18 12:06:36.75: [14976]: RECV/CQ: Bad 1D pixel count, row 28, got 2619, expected 1728
Feb 18 12:06:36.75: [14976]: RECV/CQ: Bad 1D pixel count, row 29, got 1076, expected 1728
Feb 18 12:06:36.75: [14976]: RECV/CQ: Invalid BlackTable code word, row 30, x 334
Feb 18 12:06:36.75: [14976]: RECV/CQ: Bad 1D pixel count, row 30, got 334, expected 1728
Feb 18 12:06:36.75: [14976]: RECV/CQ: Bad 1D pixel count, row 31, got 4401, expected 1728
Feb 18 12:06:36.95: [14976]: RECV/CQ: Bad 1D pixel count, row 32, got 1830, expected 1728
Feb 18 12:06:36.95: [14976]: RECV/CQ: Bad 1D pixel count, row 33, got 1733, expected 1728
Feb 18 12:06:37.17: [14976]: RECV/CQ: Bad 1D pixel count, row 34, got 2439, expected 1728
Feb 18 12:06:37.99: [14976]: RECV/CQ: Bad 1D pixel count, row 35, got 3220, expected 1728
Feb 18 12:06:38.61: [14976]: RECV/CQ: Bad 1D pixel count, row 36, got 1802, expected 1728
Feb 18 12:06:39.25: [14976]: RECV/CQ: Bad 1D pixel count, row 37, got 1793, expected 1728
Feb 18 12:06:39.45: [14976]: RECV/CQ: Invalid WhiteTable code word, row 38, x 502
... which repeats alot until you get to the end of the page send:
Feb 18 12:07:20.11: [14976]: RECV: 124 total lines, 98 bad lines, 55 consecutive bad lines
Feb 18 12:07:20.11: [14976]: RECV: REJECT page quality, 20% good lines (95% required)
Feb 18 12:07:20.11: [14976]: RECV: end page
And the error reason given in the email is:
The full document was not received because:

V.21 signal reception timeout; expected page possibly not received in full {E111}
Would this suggest a line noise issue of some sort? Or a problem with the VOIP not passing a clean signal through due to bandwidth issues? Or something? :oops:

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Dazzled
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Re: Fax2Email image quality?

Post by Dazzled » Thu Feb 18, 2010 1:09 pm

All pdf email attachments are ultimately translated into a fairly low resolution tiff file for fax transmission by an Exetel script, whereas PSTN fax machines scan and print as tiff by default, so no conversion is involved.

I am simply guessing here, but if you do the conversion on your own computer you might locate where the resolution goes. I often have to extract material from pdf documents and sometimes have to fiddle quite a bit, as many pdf to image translaters and editors give poor resolution.

Guessing again, but the most likely translation software in Exetel's script is Imagemagick http://www.imagemagick.org/script/index.php, which is ported to most machines.

trk
Posts: 59
Joined: Fri Feb 12, 2010 12:38 am
Location: Brisbane

Re: Fax2Email image quality?

Post by trk » Thu Feb 18, 2010 1:21 pm

Thanks for the reply, but I guess I didnt explain myself properly :D

The problem isnt resolution, its the noise that appears. To give you an idea I just sent a bit of a chiller catalogue which has a nice collection of images, text, tables, etc.

This is the result:
http://www.filedump.net/dumped/fax00006 ... 459335.pdf

EDIT: This is the original fax contents, printed to a PDF from Joyfax's "outbox" (ie: it has already been converted to the lower resolution and B&W of a fax):
http://www.filedump.net/dumped/7ba3ecbf ... 459813.pdf

Clearly there is "something" wrong (and the fax ultimately failed) but I'm just not sure if its our end or not. I have a fax that I sent (and subsequently received, after being signed) from yesterday which is crystal clear even after being printed, scanned and refaxed so I suspect its not JUST our end. The problem is trying to work out whats causing the noise when sending to Exetel - is it a problem with error correction? A compatability issue between our devices and theirs? Noisy VOIP line amplifying a problem we have with our setup? Or theirs?

I really wish we could abandon fax altogether, but such a huge percentage of our work is received via fax from companies that are unwilling to miagrate to email that we cant :(

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Dazzled
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Re: Fax2Email image quality?

Post by Dazzled » Thu Feb 18, 2010 1:36 pm

I see what you mean. The transmitted document is ruined, but note that white space does not have unwanted artefacts (this is also compressed in the tiff). Random signal noise would be expected all over the document. This looks like mucked up raster lines,and might yet turn out to be conversion errors. Resolution looks ok.


PS I just converted your original pdf using imagemagick. The loss of resolution was as expected, but I did not get any raster line errors.

William M
Posts: 510
Joined: Wed Mar 21, 2007 1:28 pm

Re: Fax2Email image quality?

Post by William M » Thu Feb 18, 2010 2:15 pm

Hi trk,

What you're referring as Dazzled advised isn't a resolution issue and not a conversion issue.

From the detailed logs you provided
Feb 18 12:06:36.55: [14976]: RECV/CQ: Invalid WhiteTable code word, row 25, x 142
Feb 18 12:06:36.55: [14976]: RECV/CQ: Bad 1D pixel count, row 25, got 142, expected 1728
Feb 18 12:06:36.55: [14976]: RECV/CQ: Bad 1D pixel count, row 26, got 3203, expected 1728
This indicates a failure to receive part of the fax due during transmission, this can attributed to multiple reasons ie quality of signal. Hence the fax platform applies error correction to attempt to continue receiving the fax and from the document provided that is the result of the error correction. In this instance the error correction hasn't provided much but in other circumstances its effective to ensure a complete fax is received.

At this stage we are undertaking methods to increase the receiving quality pending purchase of new hardware and implementation of new protocols. I cannot completely rule out you end, so pending the upgrades the picture should be clearer.

Cheers Will

trk
Posts: 59
Joined: Fri Feb 12, 2010 12:38 am
Location: Brisbane

Re: Fax2Email image quality?

Post by trk » Thu Feb 18, 2010 3:55 pm

I just got my wife to send a fax to both the Exetel Fax2Email number, and our workshop number. The fax came out clearly on both.

Obviously the problem is specific to our fax, sending to Exetels fax. We can send to others fine, others can send to us fine. We can use Email2Fax to get Exetel to send us faxes fine. But for whatever reason, we cant send to Exetels Fax2Email service. Yet others can send to them fine.

Lawd, I hate facsimile.


EDIT:
Us to Exetel:
Sender: xxxxxxxxxxxx
Pages: 1
Quality: Fine
Size: North American Letter
Received: 2010:02:18 15:12:43
Time To Receive: 0:00:54
Signal Rate: 9600 bit/s
Data Format: 1-D MH
Error Correct: No
CallID1: xxxxxxxxxxxx
CallID2:
CallID3: <NONE>
CallID4: xxxxxxxxxxxx
Received On: ttyIAX-I0
My wife to Exetel:
Sender: xxxxxxxxxxxx
Pages: 1
Quality: Fine
Size: default
Received: 2010:02:18 15:47:17
Time To Receive: 0:00:19
Signal Rate: 9600 bit/s
Data Format: 2-D MMR
Error Correct: Yes
CallID1: xxxxxxxxxxxx
CallID2:
CallID3: <NONE>
CallID4: xxxxxxxxxxxx
Received On: ttyIAX-I0
CommID: c000279542
So... size is different, Data Format is different and Error Correct is different. How the hell do I change those.... (to reiterate - I really hate faxes)

William M
Posts: 510
Joined: Wed Mar 21, 2007 1:28 pm

Re: Fax2Email image quality?

Post by William M » Thu Feb 18, 2010 4:50 pm

I can't guarantee that the settings are changeable, but you'll need to specify what fax machine you're using for more info.

Cheers Will

sable
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Joined: Tue Jan 20, 2004 9:28 am
Location: NSW

Re: Fax2Email image quality?

Post by sable » Thu Feb 18, 2010 5:39 pm

Sorry to hijack this thread.
At this stage we are undertaking methods to increase the receiving quality pending purchase of new hardware and implementation of new protocols. I cannot completely rule out you end, so pending the upgrades the picture should be clearer.

Cheers Will
Will,

Does this mean that there could be an improvement to the Fax to email service, more specifically the problem with receiving faxes longer than 3-4 pages?

William M
Posts: 510
Joined: Wed Mar 21, 2007 1:28 pm

Re: Fax2Email image quality?

Post by William M » Fri Feb 19, 2010 8:44 am

Yes, there should be an improvement.

Cheers

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