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Can someone recommend me a handheld scanner for textbooks?
#9
PixLab Wrote:Um... I feel that you do need a wake up call, those pseudo review's website want to sell product only

Actually the purpose of the "review" was to say that I noticed that the choices for dedicated book scanners aren't too diverse in terms of models. I mean for the characteristics I've been looking. But yes I agree with you about what it is intended with those.

Regarding your suggestion about Amazon, I've been doing exactly that for other products but since I am not very familiar with scanners I just wanted to ask people who have used these the most.

I didn't know about that complain about the problem which arises due the edge of the wand type scanner. In the previews and examples shown it appears to be that it is slim enough to sweep covering a little bit of larger portion of the middle as when you rub through the surface you can travel tangentially to the rounded corner. For that specific reason I thought that such distortion could be minimized but it appears not. So thanks for that advise.

Yes. I've seen those open book stands before. In fact there is a DIY instructable here which comes with directions on how to take pictures of the book and use it as a scanner.

I took a closer look at your example and this shows a little bit my concern. How to reduce that "rounded distortion" near the middle. It appears to be that when you use the black and white filter this is aggravated. Perhaps that if you use that wedge style book stand and take a picture parallel to one page it might produce a better result?.

PixLab Wrote:Money wise...
The different ones with a stand are basically just camera (I won't be surprised if they are webcam camera/sensor)! Yes you read well they are 18 to 20 Mega pixels camera on average, thus my smartphone which is an oppo A92 (it's a "free" smartphone, as every 2 years my provider give me a new phone with my plan, just to tell how cheap my smartphone is) can do a 48MP picture ➤ way way better than those "webcam" camera on those scanner with a stand for $500.

Thank for that information, actually I didn't thought much about it. But you have a point here. But there are some aspects during postprocessing which do concern me. How do you deal with the lightning and consistency?. In a flatbed scanner there is a sensor I believe that travels through the surface and gets the image maybe this same optical principle is used in the wand type of scanner. But in the others which are the arm type and the professional model which you posted above it appears that there is something more that is done to the image so that in the end it looks nicely.

I mean in the flatbed scanner and the wand type the sensor is closer to the surface rather than the camera based ones. So this "might" produce a more consistent and better result. The same as those roll based which scan a single page models. Again, I am not sure if in terms of accuracy from the megapixel aspect it would matter much. Because when you take a picture there is some separation between the source and the camera you have to control other variables as mentioned above. These have to be processed later processed.

At this point, I can tell you that I might want to try the camera thing to see the result. Which app do you think will yield the better results for this?

PixLab Wrote:A question remain, did you search for a PDF version on the internet?

Actually there isn't a pdf version of that collection. There is a digitalized version of a compiled book from that collection but it isn't the same and the quality is not good. Probably lesser nice than your example, there are even chapters which are difficult to distinguish from some formulas.

Ofnuts Wrote:Actually a bad idea. You can definitely increase contrast to make the page background white, perhaps after equalizing the lighting over it, and the characters black. But a pure threshold is going to make pixellated edges and specks all over.

Btw, this is what you get with at scanner app on an Android phone (Xiaomi Note7). Metal ruler included so you can ascertain how small some characters are (like the exponent "θ").

Well that speaks for itself. What app did you used for getting that image?. Actually the ruler kind of blocks certain characters and might be what I want to avoid.

At this point I think in terms of quality for this is. How can I reduce the background color so it is presented as "pure" white so when it is later reprinted doesn't cause some unwanted noise?.

Is there a smart filter in Gimp for that or something that you guys know?

Btw, I've already uploaded my avatar but it is not displaying correctly. Why is that in the forum?. It is shown the icons of not loaded picture. Can this be fixed?. I tried to delete my picture and upload it again but the problem persists. What can I do?.
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RE: Can someone recommend me a handheld scanner for textbooks? - by Chemist116 - 05-04-2022, 06:40 PM

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