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Re: Czur ET24 Pro first impressions

Posted: 26 Sep 2022, 15:43
by TS Zarathustra
It did seem to me, reading the first post, that your problem was mainly lighting and not being able to rotate the scan less than a whole degree. That is why I made that expectations comment.

Lighting is very important, specially when you have glossy paper. Proper light will do more than most other things to improve quality. Including shading in tables.

There was also mention of:
Software crashing. Mine is stable on Win 7. I don't have ET24 Pro so I cannot say how that would run.
Not autodetecting the spine. I bypass that issue by putting the book in the same location for every page. That also bypasses the rotation issue you have.

It does seem that the ET24 is not a good fit for your scanning methods and some other solution would be better.

Re: Czur ET24 Pro first impressions

Posted: 26 Sep 2022, 16:08
by aestetix
Lighting was an issue, yes. But this scanner is advertised as having built in lighting, and optional side lights that I paid extra for. I expected it to come with suitable lighting for ordinary books make of commonly used paper and ink. I don't think that's unreasonable given its cost.

As for the software, it says it supports Win 8 so I expect it to support Win 8. Do you not encounter the same bugs? The awful UI that doesn't work like every other Windows app?

I kept the book in the same place, but the location of the page split moves as you proceed through the book. It will only remain constant if you have something like a ring bound book or small paperback where the print doesn't go too near the centre.

In the case of ring bound books I get vastly superior results using a ScanSnap document scanner and the free ScanTailor software. Incredibly, that free app can rotate in increments of less than 1 degree. Fujitsu supply a plastic wallet that lets you scan up to A3 too.

It just doesn't work the way they claim it does. What's most frustrating is that with some obvious and simple improvements it could be so much better. Why mess around with lasers and straightening the pages when they could simply use the tried and tested V shape with two cameras? It would be more compact too.

If their support wasn't completely useless it might not have been so bad, but they have deep problems on that end too. Overall it's just a very poor product, made worse by awful software that suffers from ridiculous limitations, and useless support staff.

Re: Czur ET24 Pro first impressions

Posted: 26 Feb 2023, 00:24
by Keeline
I have three of the CZUR scanners — Aura (2019), Shine Ultra (2020), and ET24 Pro (2022). I don't use the Shine Ultra at all because it does not have the laser lines for curvature detection as the other two models do. But using them for 4+ years and scanning several thousand magazines and books gives me some insight on what these can do and cannot do and how to get them to work as well as possible. They are not perfect and have many quirks in the hardware and software. But for the price point and the specific task of scanning books with page flattening, they do very well.

The ET24 Pro was about $400 on IndieGoGo (higher now) and whenever comparing the results with something that might use two DSLRs or even cell phone cameras should keep this in mind. The page flattening is a feature that 4- and 5-figure professional scanners for libraries don't offer.

Lighting is always important on any photography and book scanning is no exception. In 2019 when I first started using the Aura, I set it up on the dining room table with a chandelier with compact fluorescent bulbs. Since the Aura and software does not have automatic white balance (it should), the images picked up a blue tint from the lights. Warm white LED bulbs were better. CZUR does offer a light box to better control the lighting.

Both the Aura and ET24 that I have include clip-on "side lights" that project light at a 45° angle. The default light is next to the camera and glossy subjects such as clay-coated papers will have an undesirable glare if used. The side lights do better. If that is not enough light, it is possible to supplement the lighting with USB rechargeable LED desk lamps such as the ones I bought from Bostitch (see below).

The theory of the yellow "finger cots" is that the software will remove them. In my experience, it only does this about 95%, leaving a 5% yellow ghost that was mentioned. Lighting can minimize this. I also found them a strain on my fingers. So, I stopped using them early on and use either an ivory-colored plastic letter opener or disposable bamboo chopsticks. These let me keep my hands farther from the page edges. If my hands are seen by the software, I will sometimes wear a black knit glove which makes it invisible to the software. Wearing two gloves makes it hard to turn the pages though. The chopsticks are easy for me to ignore in the pages as seen below.


I am not satisfied with the OCR in the CZUR software. It is too slow. I either save the pages separately for later processing (Photoshop and/or ScanTailor Advanced) or export to PDF without OCR and use another program (Adobe Acrobat or OCRmyPDF) for that function.

The camera in the ET24 is 24 megapixels. The nominal imaging are is B-size paper (11x17 inches) or A3. The effective resolution with a standard configuration is 320 dots per inch. This is OK but I'm sure some DSLRs may be higher, especially if one 24 megapixel camera is devoted to each facing page.

Some of my subjects are larger than 11x17. I have some magazines that are about 14x22 inch spreads. To achieve this, I elevate the scanner about 3 inches with boxes covered with black felt (to make the edges invisible to the software). Obviously this reduces the resolution to about 250 dpi.


This setup requires a larger black surface so I use a leather-covered steel Ikea Rissla desk mat (as seen above). Being steel, small magnets can be used to hold down subjects. Sometimes I use a large piece of Museum Glass to hold items like dust jackets or brochures flat for photography.

Although the CZUR products are not perfect. They are good. There are forums on Facebook where people exchange tips on how to use them well. Or we can further discuss it here if you are looking for ways to improve the results to the limit of what they can do.


Re: Czur ET24 Pro first impressions

Posted: 26 Feb 2023, 06:56
by aestetix
Thanks James.

I see from the examples you posted that you are scanning magazines, which tend to be easier to lay more or less flat. As a book scanner, Czur hardware is useless. It can't fix the curvature of the pages, and it can't handle print that goes near the spine. The examples you posted are close to ideal for their hardware.

For the money they are not worth it at all. If you have any DIY skills at all then I'd save yourself a lot of cash and get a cheap used DSLR on eBay, and make a simply plexiglass/plastic pipe jig to flatten the pages. All in you can have a very decent camera, jig, stand, and lights for $100 of less.

That will also free you from the crappy Czur software, and allow you to use something superior like Scan Tailor. Tesseract for OCR and assembling a PDF.

Have you noticed that the Czur software destroys shading in diagrams? Even for magazines it's borderline because of that. For things like datasheets and technical books, it's completely useless because that vital information is lost.

It's actually a tragedy, so many documents and technical books have been scanned with this crap and now need to be re-scanned or heavily edited to fix the flaws in their software. It wouldn't be so bad if Czur's software let you easily export the raw images for processing with better apps, but it tries hard to prevent you doing that. Who knows how many tens, maybe hundreds of thousands of hours have been wasted on those things.

Re: Czur ET24 Pro first impressions

Posted: 27 Feb 2023, 01:26
by Keeline
No, i have scanned a wide variety of items with the Aura and ET24. Some of the books were between 600 and 700 pages. Even the copy of The Archipelago on Fire that I showed was about 200 pages.

Among the more challenging books to scan were thick pulp paperbacks from the 1890s. Another Jules Verne book like this was 312 pages.

I already use ScanTailor Advanced and Tessaract (with OCRmyPDF) and ImageMagick. I mentioned most of these in my reply above.

It is possible to get satisfactory results from CZUR devices but it takes a little patience and technique. Best of luck to you.


Re: Czur ET24 Pro first impressions

Posted: 27 Feb 2023, 05:28
by aestetix
Do you have any examples you could share with shaded diagrams, or text near margins? We will need a photo of the original for comparison.

Maybe if you only want a "good enough" readable text Czur is okay, but a lot of people want to use them for creating archival copies of rare documentation for example. They just don't work for that kind of thing.

Re: Czur ET24 Pro first impressions

Posted: 27 Feb 2023, 08:05
by cday

Looking at the Czur software interface shown in this earlier post the software seems to provide quite comprehensive control of the images captured, have you for example tested scanning using different Greyscale settings, rather than the automatic setting selected in the image?

And does the scanner have a comprehensive PDF user manual which you could upload?

Re: Czur ET24 Pro first impressions

Posted: 27 Feb 2023, 09:08
by aestetix
I have experimented with the settings. It's impossible to get good results. By "good" I mean with shading intact, readable, not too warped, white paper and reasonably dark text.

The frustrating thing is that it could be good. A stand to hold the book open at 90 degrees, and simpler but better software would be a great product. Instead they keep making new versions of this flawed design.

Re: Czur ET24 Pro first impressions

Posted: 27 Feb 2023, 12:37
by Keeline
Going to the PDFs I have made from vintage series books, here is an example of a halftone frontispiece. The image is not especially close to the gutter. Notice though that the pages are flattended on this 216-page book. On the left the tip of my letter opener can be seen. On the right is the tip of the bamboo chopstick. This is how I hold down the pages instead of the yellow finger cots. As I wrote before, they are easy for me to ignore when reading a story.


The Verne books I scanned (which are often thicker) tend to have engravings that are based on paintings so they are closer to line drawings with crosshatches than halftones.

For most of my books I prefer to retain the color of the paper as well as the system can reproduce. I use a Mac so the gamma defaults there will be different than a Windows or Linux view of the same.

I find that the color matching is not as good as a quality camera with good lighting. I have considered getting a color calibration reference to include with the photography to get a sense of adjustments that might be needed other than simply eyeballing it to what looks good.

I have used the Aura and ET24 extensively and had some good results and some that required a do over because something was not quite right.

CZUR does have a cradle on one of thier high-end models. However, I don't know if it would work as well for something like the ET24. At the neck of the unit is a set of laser line emitters that project the lines on the scanning surface or the open book. If it is on the mat, the lines are straight. When a book with curved pages is imaged, the lines show curl. This red line is interpreted by the software for the curvature flattening algorithm. Pages with red ink often confuse this so may need manual selection.

The curvature flattening only works for the open book mode of the scanner. Select the one on the right that looks like an open book. Other modes will project the 3 laser lines but don't use them.

The 3 laser lines should be all projecting on the pages of the book or you will have issues. Position the open book so they are about in the middle. If one is off the edge (straight line on the mat), this will confuse the center line calculation.

Although the software claims to let you adjust the curved laser lines, I have not had success with this. The software may hang. It is easier to reimage the page spread and get a better result the next time.

I do find that I often need to adjust the center line after imaging a spread. When I am done with a batch of pages, I return to the editor/viewer mode. Open the tool to adjust the center line and drag it to the proper place when needed. This recalcualtes both the separation of the pages but also where it will do the flattening of the images. So something that looks bad at first can often be fixed in this way.

The other thing I have to fix a lot is cropping the pages. Often the foreedge of the pages is picked up in the camera and I don't prefer to have this in my final product. There is both cropping on a per-page basis, which I normally use, and cropping for a run or selected pages. Note that the default is to clear the selection box which is almost never what you want. Instead you want to trim to the selection box. It is a bad default. A mistake cannot be undone. You can only reimage the page spread. It can be very frustrating to forget this.

Items that are very flat, such as a spiral or GBC-bound book or stack of documents can be a problem because the laser lines don't have enough data to work from to sense the center line or gutter of the book. I find that when it is confused, it picks a bad default of something like 10-15° from vertical which is almost never what you want. The magazine I showed was also flat. The solution for this was to define two page-sized rectangular selections and make sure that the publication is properly positioned before starting the imaging. It is not immediately obvious that one can have multiple page selections and I discovered it by accident when I tried to redrag a rectangle and found that I had a second one.

There is a PDF and some YouTube videos for the CZUR products. None of them are particularly advanced. The PDF is only a few dozen pages and people have asked for more. Obviously this is a Chinese product that is sold around the world. So producing a long PDF with a couple dozen translations is a bit of a chore. The marketing material from CZUR shows that nuances of English can be a challenge for them. But their English is 100x better than my French or Mandarin would be so I have to give them some credit for trying even if there are the occasional awkward phrases. We've all seen this, even among native-English speakers who are better with code or building than writing documentation. I've made a suggestion of some kind of Wiki system with trusted users having edit access to write more detailed documentation and translations of it. If CZUR does not back it, it may have to be a community project with small tips and techniques to get the most from the CZUR.

One frustration with the CZUR devices is that each one has its own application. So since I have three devices, I have three applications. As their product line grows, older devices won't get as much attention or updates to their applications. It would be wiser to have a single application that can detect the device and show the features that apply to it. Then as new features are developed, they can be available to the older devices. CZUR seems unlikely to adopt this, however. It's a bit like having a company that makes webcams and none of them are really compatible with the other. Each has their own software/driver. A lot of niche peripherals run into this problem.


Re: Czur ET24 Pro first impressions

Posted: 27 Feb 2023, 13:29
by aestetix
For that use case where you are okay with the old paper colour, mismatched between pages, and foregoing machine readability, these scanners are okay. You say you flattened the pages, although there is still some curvature visible. If the software was better it would be able to use horizontal lines on the page, as well as the laser lines. That said, I don't think it does a good job even with the lasers. It seems to skew only, not expanding the narrowing created by the curvature.

Just as a test I put those pages through ScanTailor to experiment with, and the results are decent. First you can see how much it deskewed one page:


The final output of the picture page looks like this:


I'm not sure if you uploaded the original resolution, it seems rather low but the Czur scanners are only using what amounts to a webcam. I think the shading on the image is affected by uneven lighting on the right side too. Given the original image with just de-warping I could do a lot more, but Czur tries hard to prevent you getting it.

It retains some of the original paper colour, but with ScanTailor and possibly a post-processing script you can normalize it so that all pages are the same. Really you can do anything once you have control of the workflow.

It should be said that ScanTailor got the centre line automatically first time, no adjustment needed.

Different goals I guess, if that output is acceptable for your use case then I guess these scanners are okay. As I say, my main concern is that is getting flooded with crap, badly scanned stuff that the uploaders have not taken the time to check. If they had, they would have noticed all the flaws that actually make some of it unusable. Ideally they could upload the original images too, but Czur prevents it. If people are making archival copies they need to at least be accurate. Because of the way works when you fix one or do a better scan they end up with two copies, and I have to mark mine as the accurate one and point out the flaws in the other so people are aware of the issue, and I'm not keen on publicly criticising people who have scanned documents and books in good faith but been let down by Czur.