back to article Xerox copier flaw changes numbers in scanned docs

A German PhD student has found a flaw in some Xerox Workcentres that fudges the numbers on some scans thanks to poor data compression. Last Wednesday, computer science student David Kriesel was scanning in some building plans on a Xerox WorkCentre, and when checking the copies he found some of the dimensions of the plans had …

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  1. Anonymous Coward
    Anonymous Coward

    Geez, let's hope aircraft designers use Kyocera brand copiers. Can you imagine design specs for an aircraft fuselage being morphed?

    That is simply unacceptable. How many companies use Xerox for copying financials for audits, evidence in a criminal trial, pharmacies for medication instructions, etc. The mind boggles. I don't care if they say 'errors may occur'. This should not happen, period.

    1. This post has been deleted by its author

      1. Anonymous Coward
        Anonymous Coward

        Re: 'this is simply unacceptable'

        If a reliable analogue (or simple digital) photocopier fouled up due to small typeface and poor resolution, it would be reasonably obvious on the copy.

        This Xerox product seems more like a scanner, OCR, random editor, and printer.

        "It really is up to the user to ensure that the settings meet their needs."

        And to the vendors to tell people how their products are working, to the extent that they are actually unreliable on settings which may initially appear sensible.

        1. Destroy All Monsters Silver badge
          Thumb Up

          Re: 'this is simply unacceptable'

          If a reliable analogue (or simple digital) photocopier fouled up due to small typeface and poor resolution, it would be reasonably obvious on the copy.

          This Xerox product seems more like a scanner, OCR, random editor, and printer.

          THIS.

          Anyone who doesn't get that point?

          It's like the government giving you the "unvarnished truth". But then you look closer, underneath the retouched crisp type and....

        2. Anonymous Coward
          Anonymous Coward

          I've used these copiers...

          to photocopy my 6" penis and it came out 8" long. RESULT.

          1. rlc

            Re: I've used these copiers...

            Yes, but its low resolution...

          2. Anonymous Coward
            Anonymous Coward

            Re: I've used these copiers...

            You know Anthony, this is how you got in trouble the first time. Now, please return to your twitter account instead of bothering us here.

      2. Carl W

        Re: 'this is simply unacceptable'

        What is this Xerox device if not a printer combined with a high quality scanner?

        1. Tom 13

          Re: if not a printer combined with a high quality scanner?

          Yes that's what they are these days. But that's not what copiers were when they first came out. Back then you were bouncing a light beam off the paper onto a photoptically sensitive rotating drum that eventually transferred toner/ink to the page. It might smudge, but then the characters were illegible and you had to confirm the numbers or use a better original. More to the point, the data corruption was immediately obvious at least to the consumer.

          When we switched to the scanner/printer model because it was more useful and cost effective, it was under the assumption it produced the same sort of output. But what is apparently happening is that the system uses some sort of sample or dynamic image storing and compression that results in CHANGING THE DATA. Were I on a jury in a death or injury case and Xerox hauled out that disclaimer I'd triple the damages for vexation.

          1. ian 22
            Pirate

            @Tom 13

            Quite right, and also the current scanner/printer copiers (and especially those networked as printers) write everything to internal disc drives, where the documents stay, potentially for years. When the copier/printer is sold on, those documents remain with the device opening a security gap of huge proportions.

      3. 20legend
        WTF?

        Re: 'this is simply unacceptable'

        @ribosome 'Personally I feel managements should get rid of copiers and replace them with printers and good quality scanners'

        WTF dude?

        It's not necessarily cheaper, there IS just as much to go wrong, it takes up twice the space and requires a computer in the middle just to do a photocopy

      4. Jolyon Smith
        FAIL

        Re: 'this is simply unacceptable'

        Wrong.

        There is a very clear difference between "this low resolution copy is so crappy I can't tell the difference between this 6 and this 8" and "I can clearly see this is an 8 yet on the original it is clearly a 6"

        1. Anonymous Coward
          Anonymous Coward

          @ Jolyon Smith - Re: 'this is simply unacceptable'

          If it was 'clearly', it would not have been replaced. Apparently the copy quality was set so low and the original so bad that this combination led to the substitution. There's a warning in the manual, if anyone could ever bother to read it, about small fonts and compression. This would not have happened with larger fonts or a more sensible setting.

          Strange that users think they don't need to read a manual and yet think that the default settings should be altered at whim.

          I call this pebkac, but I've worked for Xerox for some years and seen how creatively destructive users can get: trying to put kiss-cut sticky-back labels through an ADF, or printing on stapled pages . . .

          This is almost a non-story.

          1. Destroy All Monsters Silver badge
            Holmes

            Re: @ Jolyon Smith - 'this is simply unacceptable'

            > I call this pebkac

            It isn't. It is bad design.

            1. ian 22
              Unhappy

              Re: @ Jolyon Smith - 'this is simply unacceptable'

              Re "bad design"

              Indeed. At a minimum the copier should flash a warning message to users when settings are down to the 'questionable' range. Although even trained and experienced users such as the Asiana pilots of Flight 214 will ignore warnings.

              Against stupidity even the Gods contend in vain.

          2. Anonymous Coward
            Anonymous Coward

            Re: "I've worked for Xerox for some years"

            "I've worked for Xerox for some years"

            "Strange that users think they don't need to read a manual"

            Strange that someone claiming to be an employee of a photocopier company wants to appear ignorant of the typical environment in which their products are used - dozens of users per shared "workgroup" device, generic printing capability outsourced, manuals never seen by end users, no online manual downloadable/browsable from the device for easy access (or if there is one, it doesn't tell users about it, and IT certainly don't).

            "how creatively destructive users can get: trying to put kiss-cut sticky-back labels through an ADF"

            You should see what happens when those labels go through the fuser (that's the hot high pressure bit, for readers who aren't aware). Or when OHP foils (remember them?) of the inkjet kind go through the fuser. I've seen that, because I'm out there on the same planet as the copier users. What planet are you on?

            1. Anonymous Coward
              Anonymous Coward

              @ AC 0735 GMT - Re: "I've worked for Xerox for some years"

              You should see what happens when those labels go through the fuser (that's the hot high pressure bit, for readers who aren't aware). Or when OHP foils (remember them?) of the inkjet kind go through the fuser. I've seen that, because I'm out there on the same planet as the copier users. What planet are you on?

              I'm actually on this planet. And while your post makes you look clever it also shows a certain lack of credibility. Labels print just fine on lasers (personal experience on a variety of printers from Workcentre 315 to DP6180 and DC 7000 to iGen3); it's the FreeFlow 665 scanners that eat them in the ADF's inverter.

              Transparencies (or OHP foils, as you like to call them) also work just fine.

              My grunge is with users that put their fingers on buttons that have a "Here be dragons" warning and then complain about dragons being there. But I have to agree on one point now that I have seen all the responses: The option to switch down from HQ needs to go completely.

            2. Stu_The_Jock
              FAIL

              Re: "I've worked for Xerox for some years"

              I "LOVE" calls for inkjet paper/OHP film etc melted in the fuser. Such a blatent PEBKAC is always chareable.

              But back to the article . . . 200DPI for point size 6 ??? And this guy's dong a PHD ?

              Hey, I need to copy this detailed thing, I know I'll turn down the DPI to make the file smaller.

          3. C 18
            Joke

            Re: @ Jolyon Smith - 'this is simply unacceptable'

            >There's a warning in the manual, if anyone could ever bother to read it, about small fonts and compression.

            Yes, you are right. It's there. In small print, of course.

            What the warning says is 'Small fonts are impeccable for use in documents requiring accuracy.'

            When instead it should say, and does so when printed in a larger font, 'Smalls fonts are impossible for use in documents requiring accuracy.' (The original documentation was in Japanese or some other exotic language from west of Greenwich...)

      5. Mark Simon
        WTF?

        Re: 'this is simply unacceptable'

        Yes, it is unacceptable. When text goes fuzzy, you know it’s unreliable. When it is substituted, then there is a real potential for disaster.

        Publishing a disclaimer is also unacceptable. It’s simply an admission of guilt and does not of itself make the behavior OK. A photocopier which may or may not reproduce your documents correctly is just asking people to shop elsewhere.

        Blaming the user is also unacceptable. Using a shared copier, you can’t expect all users to be aware of whatever settings may or may not have been applied by someone else. It might even have been the service technician.

      6. DAN*tastik

        Re: 'this is simply unacceptable'

        I am not an expert, but I believe that the combination of a small font face, 200 dpi equivalent and anything else on an analog copier would somehow blur the result. I am happy to be corrected if I am wrong.

        A blurry 8 ( or is it an 8? or a 3? or a B?) would make me squint and possibly double check the original just to make sure.

        A perfectly clear 8 would make me assume it is an 8 which was born as an 8, and I would just go ahead taking it as good.

        And "The normal quality option produces small file sizes by using advanced compression techniques. Image quality is generally acceptable, however, text quality degradation and character substitution errors may occur with some originals."

        If you are making a copy, it means that you are printing it and you don't care about the resulting file which will be deleted once you are done with it ( again, an assumption which can be corrected by anyone in the know ). Even if it turns out to be 300MB, do you really care?

      7. Ian Ringrose

        Re: 'this is simply unacceptable'

        With an old analog copier when its dpi was too low for the type face, the output was hard to read.

        The problem is that this copier is producing output that looks high-quality, but is not. This is unacceptable, the setting should not be on the copier, or it should add random dots to the output so it looks how quality.

        1. Anonymous Coward
          Anonymous Coward

          Re: 'this is simply unacceptable'

          Yes, on further thought I agree this is a legitimate objection, and actual numeric substitution should never occur.

      8. Andy Gates

        Re: 'this is simply unacceptable'

        These workcentres ARE scanners and printers. They have a copy function which is really "scan to temp and print out" and if you remove that, there will be riots.

        ..and now I have to grumble around checking we don't have any affected models.

      9. MrDamage Silver badge

        Re: 'this is simply unacceptable'

        I agree.

        As an ex-field tech for Xerox, I came across a number of problems that occurred simply because people were not willing to RTFM.

        I'm willing to bet in this case, the guy in question was feeding the paper through the ADF. While it is the fastest method, it can be prone to these sorts of mistakes due to small fonts, paper slippage due to not using the paper guides, crap on the glass (people dont clean the 1 inch wide glass strip thats used when the ADF is operated, only the large sheet), worn feed rollers, and so on.

        If you want good quality copies, then take the time to use the manual option, and make sure that the resolution setting is adequate for your needs.

        1. Kubla Cant Silver badge
          Facepalm

          @MrDamage

          As an ex-field tech for Xerox, I came across a number of problems that occurred simply because people were not willing to RTFM.

          It may come as a surprise to you to learn that most people in offices have more important things to do than read photocopier manuals.

          Once upon a time the photocopier was a vital piece of office equipment, and people used it often enough to know how it worked, though I don't suppose they read the manuals, even then. With the reduction in paper documents, an average person might make one photocopy a month. Meanwhile, the copiers have become much more complicated.

          1. MrDamage Silver badge

            Re: @MrDamage

            Sure, people might have more important things to do than read the manual. But that does not exempt them from actually thinking for half a second.

            All companies try to make their equipment idiot proof. The only problem is that the Universe immediately responds by creating a bigger idiot.

            And for the record, photocopiers have only become more complicated at the back end. The front end has become so simplified that any moron can use it. Unfortunately, many of them do.

          2. C 18
            Mushroom

            Re: @MrDamage

            >It may come as a surprise to you to learn that most people in offices have more important things to do than read photocopier manuals.

            Yeah, like get that shredder repaired because somebody tried to shred something with a paper clip on it, which they wouldn't have done hadn't they had to perform a fire drill when they needed time to read the effing manual for the shredder...

            We actually had a fire in our office and nobody got up to leave, because we hadn't been told that there was a drill scheduled for that day.

            Office people who don't RTFM...bane...of...their...own...lives...

    2. Anonymous Coward
      Anonymous Coward

      Aircraft designers

      Um, photocopiers tend not to go up to A0.

      1. A Non e-mouse Silver badge

        Re: Aircraft designers

        Um, photocopiers tend not to go up to A0.

        Your standard office ones don't. But large format ones do exist. Any department that does a reasonable amount of work with maps and plans will have a large format A0 copier to hand.

        1. RAMChYLD
          Boffin

          Re: Aircraft designers

          > Your standard office ones don't. But large format ones do exist.

          +1. I actually looked at a few from HP last year because some folks in my department demanded a large format printer. In the end we went with one that does not have a copier feature built in, which in hindsight is a big mistake when clients started sending us A0 blueprints and asking us to digitize those!

        2. Anonymous Coward
          Anonymous Coward

          Re: Aircraft designers

          This is correct, but the article was about office copiers. The A0 machines are very different and are designed to handle engineering drawings. Whether you use a Kyocera or Xerox A0 machine won't make any difference, contrary to the suggestion of the GPP.

      2. jabuzz
        FAIL

        Re: Aircraft designers

        Photocopies do go up to A0, it is just you are not used to such machines.

    3. Blacklight
      Facepalm

      This reminds me of Jimbo & The Set Jet back in 80's kids TV land...

      "The premise of the cartoon is that Jimbo was originally intended to be a Jumbo Jet, but his designer could not tell the difference between inches and centimetres, resulting in his diminutive size"

      http://en.wikipedia.org/wiki/Jimbo_and_the_Jet_Set

      1. Valerion

        Goes up to 11

        Maybe Spinal Tap could have blamed their Stonehenge on this.

  2. Matt Piechota

    Why do you need to compress *copy* data? Scan, OCR, etc. makes sense, but copies? They're just getting spit back out.

    1. Yet Another Anonymous coward Silver badge

      They are held in memory

      When you copy a 200page doc it scans it, copies it into RAM then does any 2-up, half side, 2 sided reshuffling, then sends it to the laser printer - which is what a modern copier is

      Some copiers also let you select extra copies of earlier docs.

      there is normally a security scare story every week about how to access old copies - which is why most companies keep a separate machine for HR/ Financials etc

      1. Carl W

        They are held in memory

        What's wrong with lossless compression, like LZW? Memory is cheap and data buses are fast these days.

        1. Destroy All Monsters Silver badge
          Trollface

          Re: They are held in memory

          Additionally, there is black magic to interdict the copying of banknotes. And possible child porn and back issues of "Insipre".

          1. Parax
            Trollface

            Re: They are held in memory

            The 'Black magic' is called the Eurion constellation. I've always wondered if it's free to use or copyright (no pun intended)... I may have slipped it into random work reports for fun.

          2. Robert Carnegie Silver badge

            Bank notes

            If the copier can recognise what money looks like and refuse to copy it, then it should be able to recognise text and not interfere with it. But then, I don't know how it does it for money. Something like a bar code to be recognised?

            1. Anonymous Coward
              Anonymous Coward

              Re: Bank notes

              look for a pattern of small yellowish rings on the note, it's that. on the UK Elgar 10 quid note it was hidden in the musical notes :)

            2. Tom 13

              This comment withdrawn.

              Anonymous Coward Posted Wednesday 7th August 2013 12:37 GMT

              has much better insight and hopefully a workable solution.

        2. Anonymous Coward
          Anonymous Coward

          Re: They are held in memory

          Sadly I'm quite familiar with the JBIG2 compression used here. It's a bilevel compression scheme (ie for 1-bit black & white images only) which can give quite significant improvements over CCITT group 4, which is the predecessor - LZW isn't used here, it's better for general compression but for bi-level images CCITT and (now) JBIG2 are hard to beat. As an example, Ar at 200 DPI you might be looking at about 30-40KB for a page of text, maybe 60% of that for JBIG2 and much more for LZW, JPEG or any other non-specialized schemes.

          The JBIG2 spec is a nightmare of options, but one core part of it is the pattern matching, where it looks for repeated symbols and replaces them with a lookup in a table. Clearly that pattern match algorithm isn't working here. The other nasty part about the spec is it specifies a decoder ONLY - an encoder is simply expected to generate a document that can be decoded by a decoder matching the spec. So lots of room for error for implementers.

          However the one thing I can say for sure is saying this is a user error is incorrect. The pattern matching is one of many compression options in the algorithm and it doesn't have to be used. If the resolution is too low (implying the pattern cannot be matched with a suitable degree of accuracy) the algorithm should fall back to a regular CCITT-style compression. Whoever wrote the algorithm has clearly set the confidence level incorrectly.

          1. John Gamble

            Re: They are held in memory

            Thank you, that was clear and informative and deserves an extra fifty up votes.

    2. Anonymous Coward
      Anonymous Coward

      There's all sorts of image processing going on in there

      the CCDs used in scanners are RGB devices which have to apply various white balance and hue corrections and, ideally, identify information-free areas over which background suppression will be run, then the image data has to be converted to CMYK before it's rasterised and handed over to the print engine for output. The rasterised dataset is reused for additional copies, so it has to be shunted into and retrieved from storage. Even black text will be captured in RGB space and then converted, and that's before we get into the wriggles of machines which output that as single or four-colour black. Regardless of the actual rated speed of the engine, users want their copy as quickly as possible once they hit the button, so any and all shortcuts that can be taken to minimise the time the machine spends working upon image data or shunting it around are seen as fair game.

      1. Anonymous Coward
        Anonymous Coward

        Re: There's all sorts of image processing going on in there

        "any and all shortcuts that can be taken to minimise the time the machine spends working upon image data or shunting it around are seen as fair game."

        If you're in marketing, maybe.

        As a user and potential purchaser, I want a copier to copy. Accurately.

        If the copy isn't good enough, and I've paid loadsamoney, I'd like a button that says "enhance" and one that says "SmartCopy" and maybe one that says "make Whheeeee noise"

        What I don't want is a photocopier that silently and invisibly and undetectably changes the content of my copy without telling anyone.

        That's not a photocopier, that's a class action in waiting.

        1. Tom 35

          Re: There's all sorts of image processing going on in there

          Our copier had a "make Whheeeee noise" button. A big green one... service guy came the next day...

          I can just guess what would happen if we lost out on a RFC because the copier had changed a 6 to an 8.

          1. John Smith 19 Gold badge
            Unhappy

            Re: There's all sorts of image processing going on in there

            "I can just guess what would happen if we lost out on a RFC because the copier had changed a 6 to an 8."

            Perhaps you already have?

            Time for a visit to Messrs Shyster, Shyster and Flywheel?

  3. Yet Another Anonymous coward Silver badge

    Not just copiers

    A CFO stood up at a board meeting once and congratulated us on a 320,000 quid sale

    We had to point out that this was "A3 20,000" where A3 is how the email had decided to print the GBP sign

  4. Destroy All Monsters Silver badge

    That sound...

    Lawyers powering up!

    OMG! We are doomed. And all for the price of a gigabyte RAM.

    1. Anonymous Coward
      Anonymous Coward

      We had a sales manager....

      called Knut and ironically the Xerox changed his name, which was handy as he WAS one.

  5. asdf

    another Xerox fail

    There are few companies responsible for more epic fails than Xerox throughout history. Hard to believe they still exist at this point. The laser printer, the personal computer, GUI who could ever make money off these worthless inventions?

  6. edge_e
    Facepalm

    RTFM

    that is all

    1. mike2R
      Thumb Down

      Re: RTFM

      Which tells you that not only is the copier capable of making an unforgivable mistake, the company selling them fucking knows about it and sells them anyway.

    2. Roland6 Silver badge

      Re: RTFM

      I assume this is a joke?

      I mean if Windows 8 and MS Office plus loads of other software can be shipped WITHOUT A MANUAL then why does a copier with a big green button labelled 'Copy' need to be shipped with a manual?

    3. Scott Wheeler
      FAIL

      Re: RTFM

      A) Users don't have the manual; B) Users don't have the admin privileges to raise the scan resolution; C) A bug like this should be fixed, not documented as a "feature".

      1. Anonymous Coward
        Anonymous Coward

        @Scott Wheeler

        Downvoted for failure to know copiers. While A and C are true, especially C, B is patently false. You do not need to have admin privileges on the copier to change the resolution.

  7. unitron
    Coat

    I must have blinked and missed it.

    I thought copiers worked like cameras, i.e., optically, where it has no idea if it's reproducing a picture of a letter or a number or someone's naughty bits.

    Mine's the very old one.

    1. andreas koch

      @ unitron - Re: I must have blinked and missed it.

      All digital, since 2000 and earlier.

      1. Tom 35

        Re: @ unitron - I must have blinked and missed it.

        It should still have no idea what you are copying, not try and guess what you wanted.

        They could have even more fun and add a spelling checker.

        1. Anonymous Coward
          Anonymous Coward

          @ Tom 35 - Re: @ unitron - I must have blinked and missed it.

          Have you ever tried to copy a banknote or a passport on a modern Xerox? You'd be surprised.

          Oh, and they also watermark the copy with an almost invisible code, so you can track the copy to the machine.

          1. Tom 35

            Re: @ Tom 35 - @ unitron - I must have blinked and missed it.

            That's totally different. Same for any recent versions of photoshop.

            It's just not going to copy a banknote, it's not going to copy it and change it to read "in dog we trust"...

            Or copy your passport and change your name to Carmen Sandiego.

  8. mr.K

    A little to the left, a little to the right

    "Legally, then, Xerox is in the clear, but that's going to be cold comfort if your newly-built house extension collapses in the middle of the night."

    Confronted with the poor "student quality" a professor in civil engineering answered drily that concrete is a highly flexible material, it can even cope with decimal mark misplacements.

  9. Bryan Hall

    So that's what happened to Obama's "birth certificate"...

  10. bazza Silver badge
    FAIL

    Use Case Fail

    Given that most photocopiers get used for copying nothing but text containing documents, it is surprising that Xerox saw fit to choose such a stingy default setting. That is pretty poor judgement on their part.

    How on earth did the person writing that manual ever think that such a characteristic would be even remotely acceptable to any end user? The phrase "It's a photocopier" should have been foremost in their mind. In trading off between accurate copying and some crazy features that almost no one ever uses, how did the latter ever come to be considered more important than the former?

    If that isn't a sign of company that's lost the plot, I don't know what else is.

    1. John Smith 19 Gold badge
      Unhappy

      @bazza

      "Given that most photocopiers get used for copying nothing but text containing documents, it is surprising that Xerox saw fit to choose such a stingy default setting. That is pretty poor judgement on their part."

      I'm not sure there is evidence this was on factory defaults. It could be the company/university set it to "economy" settings and that was one of them, along with using less ink for the black parts.

      We just don't know.

      But if this was the default that would be worrying.

      1. Anonymous Coward
        Anonymous Coward

        Re: "Copies"

        I think we need to remind ourselves that this problem does not apply to copies and only manifests when using the scanning feature.

  11. Sir Barry

    "However, Xerox says that the problem is essentially due to the settings users have put into individual copiers"

    Nope, the problem is due to the corners cut by Xerox. Modern digital Multi Functional Devices should replicate what is being copied or scanned without interfering with the content.

    Placing the blame on the user is a pretty poor way of excusing an inferior product.

    1. Tom 13

      @ Sir Barry: Not quite

      IIRC the default settings on those systems is 600dpi and they switched to 200. Even IIRIC and the default is 300dpi, that's still better than the 200 dpi at which they were scanning. So there is some user participation in the problem. I'd assign it a 95:5 split with Xerox owning most of the blame.

      Where Xerox owns 100% of the problem however is that there is insufficient warning about possible problems. In a world in which step ladder manufacturers have to put "Do Not Stand on Top of Ladder" warnings on 18ft step ladders, burying the warning in the user's manual doesn't cut it. In fact being aware of the problem and not fixing it doesn't cut it.

      1. Charles 9 Silver badge

        Re: @ Sir Barry: Not quite

        "Where Xerox owns 100% of the problem however is that there is insufficient warning about possible problems."

        Doesn't the copier throw a warning when you use lower-quality modes to the tune of, "Are you SURE you want to do this? The end result may be inaccurate."? If so, this is a case of "Warnings are for wimps" resulting in human-induced error.

        The lower-quality settings likely exist to prevent a big job getting balked partway due to an "Out of Memory" error (office copier—it's conceivable). Though I will say at this point that perhaps Xerox's JBIG2 compression system needs better tuning to help it distinguish between 6's, 8's, B's, etc.

        1. Anonymous Coward
          Anonymous Coward

          Re: @ Sir Barry: Not quite

          "lower-quality settings likely exist to prevent a big job getting balked partway due to an "Out of Memory" error (office copier—it's conceivable"

          Are you serious? Let's do some Mackay-style analysis of the fundamental numbers, and maybe then look at your logic.

          Say 300dpi. 21cm x 30cm (~A4) = 630cm2 = ~100 sq. inches.

          100 sq inches, 30k pixels per sq inch. Say 4 bytes per pixel (being quite generous here I think).

          Call it 12MB per uncompressed A4 300dpi page.

          Let's say that again.

          12MB per uncompressed A4 300dpi page.

          Quadruple it for A3.

          Still less than 64MB per (32bit per pixel) uncompressed A3 page.

          What the heck is going on here?

          So at 64MB per A3 page at 300dpi, what kind of logic (in the designer's mind or on the main logic board) doesn't have enough memory to do a decent lossless (nb you can have lossless compression with text and pictures) scan-to-print without data corruption, even if it is a multi-page job needing some intermediate storage?

          Or did I miss something?

          1. Charles 9 Silver badge

            Re: @ Sir Barry: Not quite

            You're missing two things: limited memory (which can be problematic if the run is large, and it all has to be in memory if you're going to manipulate or rearrange the results like collated or duplexed output) and image manipulation (enlarging, brightness, etc.) which have to work with uncompressed data at least partway. Plus there's the raw data being sent to the printer unit that has to be held in memory in the meantime. Depending on the model of copier, "Out of memory" can be a real issue with long or complicated jobs.

            1. Anonymous Coward
              Anonymous Coward

              Re: "You're missing two things: limited memory"

              The thing I'm actually missing is how much these "NotWork Print Centres" sell (or are rented) for.

              Anyone know?

              Then I'll know whether "out of memory" has any real relevance or not.

              How much does a few GB of persistent storage cost this year, in volume (bearing in mind that in the right circumstances the storage might actually not even need to be on the printer itself, but might be located on the print server?)?

              How much does a few GB of RAM sell for? Same consideration applies - the RAM could in the right circumstances be on the print server.

              "Depending on the model of copier, "Out of memory" can be a real issue with long or complicated jobs."

              Doubtless. In which case maybe they need to install more than 640kB of memory, so they don't have to pretend to be capable of doing things they aren't actually doing (like reliable copying).

  12. Ciaran McHale

    Same problem at higher resolutions?

    Printers can occasionally produce imperfect pages due to, for example, a drum that is nearing the end of its useful life, or a bit of spilled toner inside the machine (perhaps due to a paper jam that occurred earlier). Such imperfections in a printed page, combined with an unsafe optimisation in the photocopier make me skeptical that this problem will be limited to low-resolution copies.

  13. Anonymous IV

    Scan-dalous

    You'd think that if the scanner couldn't resolve something, it would reproduce the 'something' as closely as possible, but not arbitrarily decide that the 'something' was 'something else'. Where's the fail-safe in that?

  14. tin 2

    The device even warns 'use these low resolution settings and you may get character substitution because we compress like a bastard' (in the GUI, no RTFM required apparently), and then someone uses said low resolution settings and gets character substitution. This is a story? Should it not be a story about the user being thick? Stick it back on high resolution and shut up!

    1. I ain't Spartacus Gold badge

      One, it's called normal mode. I presume that's in the sense that many companies don't do a 'small' drink, you have regular, large, extra large.

      Two, it's a bloody photocopier. And it should be damned well copying! The people who didn't read the manual here are Xerox. It's supposed to copy stuff, not randomly substitute other stuff. Failing to resolve an unclear area is perfectly acceptable, and that's down to the user to deal with.

      You shouldn't have to read the manual to do something basic like make a copy of a document in normal mode. If you want to do double-sided, stapled, enlarge, multi-coloured and sorted documents, then a manual may be required.

      1. Charles 9 Silver badge

        Excuse me, but how do we know the copier wasn't being tasked with anything complicated, such as storing hundreds of pages in its (limited) memory, performing re-collations, enlargements, lightening/darkening, etc., all of which require keeping the pages in memory for processing and re-arranging.

        In other words, what we call a "photocopier" is a whole other beast from 20 years ago, and in the process of "copying" we expect it to jump lots of hoops. That adds necessary complexity to the machine.

      2. Anonymous Coward
        Anonymous Coward

        The default setting IS high.

        You have to deliberately set it to normal and then confirm the substitution warning before the setting takes effect.

        But OKOKOK, I agree now: This function has to go, the "I'll hit the enter button without reading anything" user should not be taxed with options.

        1. Anonymous Coward
          Anonymous Coward

          Issue does not occurr on basic copies

          because compression is not used when making basic copies.

          RTFA.

    2. Tom 35

      It's a work group printer

      Why would a copier have a setting that should be called "please screw up my copies" at all, and why do you think it's OK because one "thick:" user selected it (maybe so they could print two copies of a 500 page document double sided), and maybe others came along used the copier without knowing how it was set, or even knowing it has a "please screw up my copies" setting.

  15. Jonl

    Credit

    Oh Look! The copy of my bank statement says I have some money in the bank. Guess I won't be buying a Xerox copier.

  16. newspuppy

    This is a KNOWN FEATURE... READ THE MANUAL...

    If you read the documentation from XEROX... it claims that on scanning it is a known problem that "Image quality is

    acceptable but some quality degradation and character substitution errors may occur with some

    originals." page 107 from http://www.cs.unc.edu/cms/help/help-articles/files/xerox-copier-user-guide.pdf

    also on page 129 we have the following: "Quality / File Size

    The Quality / File Size settings allow you to choose

    between scan image quality and file size. These settings

    allow you to deliver the highest quality or make smaller

    files. A small file size delivers slightly reduced image quality

    but is better when sharing the file over a network. A larger

    file size delivers improved image quality but requires more

    time when transmitting over the network. The options are:

    Normal/Small produces small files by using advanced

    compression techniques. Image quality is acceptable but some quality degradation and character

    substitution errors may occur with some originals."

    Of course, for NORMAL it will do substitution.. but what the hell...... It is in the manual.... you do read the manuals, no?

    1. I ain't Spartacus Gold badge

      Re: This is a KNOWN FEATURE... READ THE MANUAL...

      It is totally unacceptable to put onto page 107 of the manual, in normal mode our product doesn't actually work for its stated purpose.

      If they put that on the front page of both the manual and the marketing materials in say 30 point type, then it would be acceptable. Otherwise not.

      Actually even then it wouldn't be. What part of copy do these fuckwits not understand? If the damned thing doesn't work on one of its settings, then that setting shouldn't be available. Or should only be available to be set by the installation engineer or local IT department, after sufficient warnings to people who understand what they mean, and may have actually seen the manual.

    2. John Arthur
      FAIL

      Re: This is a KNOWN FEATURE... READ THE MANUAL...

      And you call that a FEATURE?

    3. Roland6 Silver badge

      Re: This is a KNOWN FEATURE... READ THE MANUAL...

      >"some quality degradation and character substitution errors may occur with some originals"

      The manual only makes sense once you know the details of the scanning process and have knowledge of David Kriesel's findings. I suspect that the majority users, both 'typical' and 'IT literate', would not of read that statement and taken it to mean what David has demonstrated.

      Also you need to take account of the context of the statements you quote: Page 107 is about "Quality / File Size" within the "Internet Fax" section and Page 129 is within the "Advanced Settings" of the "Workflow Scanning" section. The "Copy" section (pages 39-66) makes no reference to this flaw. In fact due to the context the typical user would assume Xerox were referring to an image and hence meant "pixel substitution" ie. loss of detail, as "Character Substitution" makes no sense in the context of image scanning - until you understand how Xerox are actually scanning and pre-processing the image.

      I note from Xerox's responses it would seem that they were unaware of both the exact circumstances under which character substitution occurred and the exact nature of the substitution. Ie. Xerox were aware that the image patch size they were using for JBIG2 could cause substitution but hadn't worked through the full ramifications of such substitutions (or are keeping quiet in the hope that the full ramifications don't become public...)

  17. John Smith 19 Gold badge
    Unhappy

    Who has *seen* the office photocopier manual in your office?

    No I haven't either.

    I'd also note that Xerox put a lot of graphical and written help text into their units, probably much of which already exists in the manuals, but which they doubt you can get hold of.

    This is a UI fail. Yes I know the floor standing ones are network linked MFP which just happen to be called copiers but how many people use them for central scanning and distribution?

    IOW who wants those smaller (but quality compromised) files IRL?

    I sense lawyers going to "attack mode"

    1. Anonymous Coward
      Anonymous Coward

      Re: Who has *seen* the office photocopier manual in your office?

      "I sense lawyers going to "attack mode""

      Yes, Messrs Sue, Grabbit and Run are mounting up, surely ...

      1. John Smith 19 Gold badge
        Happy

        Re: Who has *seen* the office photocopier manual in your office?

        "Yes, Messrs Sue, Grabbit and Run are mounting up, surely ..."

        Ah, SS&F's sister firm in the UK.

        Yes I think Xerox may well be hearing from them too.

    2. Darryl

      Re: Who has *seen* the office photocopier manual in your office?

      We have a pile of brand new 5755's here and the UI is horrendous. On the 3" x 4" screen, important notifications like "Sorry, I don't have that paper size" or "I'm out of toner" are written in 5 point black type above the 'main menu' area, so nobody notices them, then phones me to complain.

      Not sure what's so hard about a window popping up on the screen to let users what's (not) going on

  18. Sealand
    WTF?

    A copier?

    Isn't a copier supposed to copy what it sees?

    This device should be marketed and sold as an "I'll print whatever I think is there - do you feel lucky, punk?'er"

    One more thing we can no longer trust. The list is getting shorter all the time, methinks.

  19. Anonymous Blowhard

    Which Models?

    "Kriesel found the flaw was present on the WorkCentre 7535 and 7556 models"

    Are they sure? Or did they send a copy this information to everyone?

  20. Roland6 Silver badge

    The problem is much more pernicious...

    The problem which Kriesel researched is with the scan/copy module and the internal memory image it creates, as others have pointed out once the image has made it's way into RAM it is then made available to other functions such as: PDF (with/without OCR), image (TIFF/JPEG etc.) - unless others can point to the block substitution error being introduced by the print module.

    Kriesel has identified one particular manifestation of the compression and substitution flaw, given the nature of the flaw there will be other potentially less obvious manifestations, the question is whether these can be spotted as simple spelling mistakes or like Kriesel's case result in a clean inaccurate copy that gives no indication to the reader that a scanning error has occurred.

    We should remember that 200 dpi is typically used as a normal resolution for everyday office document scanning and smaller fonts are very common in the "small print" parts of normal business documents ...

    1. I ain't Spartacus Gold badge
      Happy

      Re: The problem is much more pernicious...

      We should remember that 200 dpi is typically used as a normal resolution for everyday office document scanning and smaller fonts are very common in the "small print" parts of normal business documents ...

      Damn! So are you telling me that I need to check that clause in the small print with my home insurance provider? I knew that it was too good to be true when I read, "in the event of a fire, you will be temporarily re-housed, and we will also provide hot and cold running call girls, plus unlimited pizza and beer."

      1. Roland6 Silver badge

        Re: The problem is much more pernicious...

        Just to add to my previous comment: we should remember that the problem is with the JBIG2 compression system those copiers use, what we don't know is do other manufacturers use this system...

        1. Anonymous Coward
          Anonymous Coward

          Re: Not the actual compresion scheme itself

          The compression is just a spec, from which implementers can choose a bunch of optional aspects that they wish to include / utilise. So Xerox's implementation of JBIG2 works differently from other manufacturers' implementations.

  21. Stevie

    Bah!

    By Jove, I hope my pharmacist has the hi-res setting enabled when my doctor sends my prescriptions through.

    The danger of a wrong dosage doesn't bear thinking abarghurrrrrgle!

    1. ian 22
      Mushroom

      Re: Bah!

      Stevie this is no laughing matter! As automation becomes the norm, humans will exercise less and less brain power. Not to mention unexpected behavior on the part of the systems in question.

      The first automation related disaster I'm aware of was the Mount Erebus Disaster in 1979 (http://en.wikipedia.org/wiki/Air_New_Zealand_Flight_901), and the latest is Asiana flight 214 last month. As automation spreads, I expect more failures.

  22. Anonymous Coward
    Anonymous Coward

    Perhaps the copier will have its firmware upgraded and a disclaimer printed on the copy?

  23. PDF PRO
    Alert

    Everyone is missing the point

    What is wrong with everyone. Are you all missing the point.

    This issue relates to the JBIG2 compression which is only used when selecting the highest copression rate to reduce the file size. It has NOTHING TO DO WITH TAKING A COPY OR PRINTING.

    Yes, granted, when you copy, the device scans then prints, but no compression is used in this process.

    It is only when you are creating an external file, the device offers you the option to set a higher level of compression but warns you that by selecting this you may loose data integrity.

    Image quality and data integrity is always traded off when you ask for a very high level of compression at a low resolution.

    1. Stevie

      Re: Everyone is missing the point

      No, you are missing the point. These machines are often also used as fax/email printers, by people like doctors and pharmacists (and engineers, who we have found time and time again often have a frighteningly tight focus when it comes to applied intelligence - see story in sharktank last week of an aerospace engineer who wrapped his PC in a blanket to stop the fan noise and cooked the thing).

      It isn't reasonable to ask people whose job is nothing to do with computers or copiers or compression algorithm internals to cope with this nonsense. It is the responsibility of the copier supply drones to ensure that a cock-up cannot happen due to the copier designer designate being a total science nerd with zero real-world contact. If there is a danger, there should be a lego-brick sized red light flashing on and off to alert someone of the danger.

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