Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Another book shooter Mk-V

Built a scanner? Started to build a scanner? Record your progress here. Doesn't need to be a whole scanner - triggers and other parts are fine. Commercial scanners are fine too.
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Ant1
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E-book readers owned: tablet + perfect viewer
Number of books owned: 10000
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Another book shooter Mk-V

Post by Ant1 » 29 Jan 2019, 04:35

Hi everyone,

I am new to this forum. Please let me apologize in advance for my english, as I am not a native speaker.
I have a long time interest in tinkering and building stuff. Lately I decided to attempt a quick book shooter build, in order to scan older books including comic books.
I have taken inspiration of the Book Shooter MkV design and have built a rather crude prototype out of cardboard box.
Using two layers of cardboard provides good stiffness yet remains lightweight. The interior is padded with white paper to equalize lighting.
The acrylic window allows for size A4 (full page) scanning.

Image

For lighting I have used four white LED strips wired in parallel, powered by an external 12V supply.

Image

Scanning is done using a smartphone, I have an Android-based Honor 6x with 12MP and resolution is correct for easy reading.
However I struggle a little bit with the software and image processing.
I use the app "Open Camera" on Android platform to lock the focus. The images I get are OK for text recognition using OCR post-processing.
However, color images is another story because of two issues :
1. uneven illumination of the page (due to the lighting on the side to avoid reflection of leds in the camera)
2. white balance is off and there is a blue color hue (probably due to color tone of the led)
As an illustration I have taken a picture of a white sheet of paper :

Image

I have looked into software apps for correcting these issues (either a camera app in Android or a postprocessing program on a Windows computer) but there are so many I am a bit lost, so I appreciate some guidance here.
Thanks in advance for your comments,

All the best,
Ant1

dpc
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Re: Another book shooter Mk-V

Post by dpc » 29 Jan 2019, 13:43

You can do image color-correction as a post-processing step. This thread discusses the technique somewhat.

zbgns
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Re: Another book shooter Mk-V

Post by zbgns » 29 Jan 2019, 19:11

I also started from similar cardbord prototype and acrylic glass in order to test how it may work for me.
Further to your description my thoughts are following:
1. Even lighting is very difficult to obtain in this kind of device. You may try to reduce it by:
a. more square shape of the glass in order to move the light source as far as possible from photographed objects; it may help in ridding off the most overexposed area at the bottom;
b. changing angle of the light source and distance from the glass;
c. inserting some kind of semitransparent, matte film over the light source in order to diffuse the light.
2. Effects of the above may be not spectacular, but I obtained significant improvement by combination of indicated methods. In case of black and white images I find it fully satisfactory. For color images the quality depends on specific case (usually the less reflective paper the better effect).
3. It may be easier to change the lighting than rely on software post-processing to correct white balance. When it comes to the LED lighting only “neutral white” (4600K) gives acceptable results for me. I tried also “cold white” (your case probably) and “warm white” but colors were distorted, and no software method was fully effective. Nevertheless, as Open camera has manual regulation of white balance, you may obtain some improvement adjusting this.

Konos93a
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Re: Another book shooter Mk-V

Post by Konos93a » 30 Jan 2019, 08:06

first of all upload a captured page of a scanned book and one of a comic

since you go for a smartphone
check this video https://www.youtube.com/watch?v=qQLRkAkxfao and the trick with the mirror at 5.18

and from this threat my post for smartphones viewtopic.php?f=14&t=3364&start=50

now for post prossecing check this video i made with subtitles
https://www.youtube.com/user/pokemonkaipokemon

the programs are
1 vysor app android for liveview
2bulk rename for renaming
3scan tailor advance for image process
4djvu small to create a djvu
5abbyfinereader to calibrte distance betwwen glass and lens image editor and ocr (personaly i use it only for ocr)
6 notepad++ to edit boomarks
7 handyoutliner to have create boomarks on pdf or djvu
8 Koreader on ebookreader or ebookdroid for android

if is something i wrote was not get understood please ask freely

Ant1
Posts: 4
Joined: 28 Jan 2019, 07:41
E-book readers owned: tablet + perfect viewer
Number of books owned: 10000
Country: France

Re: Another book shooter Mk-V

Post by Ant1 » 31 Jan 2019, 15:37

Hi,

Thanks for your useful comments.
I feel I have some more hardware to tweak. The tip with the mirror is really clever, I will align the phone using this method.
I have neutral white LEDs on order and am looking to improve even illumination.
Here are two sample scans, one from a black and white book, the other from a color comic.
I have scaled them down for posting here but resolution is absolutely not an issue.

All the best
Ant1

Image
Image

Konos93a
Posts: 127
Joined: 19 Sep 2016, 10:00
E-book readers owned: kobo aura,kindle 1,kindle pw3,pocketbook inkpad 2
Number of books owned: 3000
Country: greece

Re: Another book shooter Mk-V

Post by Konos93a » 31 Jan 2019, 19:35

can you upload a link with wetransfer?

about step 5abbyfinereader to calibrate distance between glass and lens .
a flat -scanner can scan at 150 , 300 ,600 ,1200 dpi
abbyyfinereader has an option Detect Optional Resolution . it suggest the best dpi it can recognize . the more dpi the better the distance you have

i start set scanner with smartphone when i compare a xiaomi redmi smartphone capture photo with ones off the my a3300 . i think that from my smartphone it looks better, even if you process black and white you cant really see the difference.

if the program suggestion is more than 300 dpi every ocr will have the same results.
if the program suggestion is more than 500 dpi every black and white converted page from any device in the same photography conditions, then every difference is not easy visible from the eye.
----------------------------------------------------
to trigger camera use an selfie sticker with cable. take out the chip with the button . put it inside to flat piece of wood and tie them up with tape.
----------------------------------------------------
for color images i am not really the right person to suggest you stuff.

So the right angles between source light and the glass are the ones that reflection of the source on the capture photo is not visuable. can you capture photos with the leds in a different spot and with a different angle?

i think that the photos you upload have good light if you want to reduce light use a led controller or a dc-dc converter

Ant1
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Joined: 28 Jan 2019, 07:41
E-book readers owned: tablet + perfect viewer
Number of books owned: 10000
Country: France

Re: Another book shooter Mk-V

Post by Ant1 » 11 Feb 2019, 04:42

Hi,

I have been fiddling with a few hardware improvements.
First item was to improve the color, switching to more neutral white lighting. This was achieved by using 4000K white leds instead of 6000-7000K.
Second item was to get more even lighting. I tried a few different solutions but the best results have been achieved by using a single row of leds nearest the window. If you get the leds farther away, the illumination difference gets obvious.
I salvaged a thin row of 30 leds (10W) from a ceiling light (the kind that looks like a backlit tile) and this really did the trick.
Here's a pic of the scanner :
Image

And here's a pic of a scanned color page :
Image

White could be whiter but this quick test was done without any adjustments to the white balance of the camera.

Regards,
Ant1

cday
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Country: UK

Re: Another book shooter Mk-V

Post by cday » 11 Feb 2019, 15:41

Good progress, and your image enhances quite well with a simple levels adjustment, although I had to use quite aggressive settings that may have had some adverse effect on the image if it is examined closely:


IMG-20190210-191017_Levels.jpg
IMG-20190210-191017_Levels.jpg (109.72 KiB) Viewed 547 times

With a less aggressive adjustment there was still some variation between the darkness of the page at the top and bottom of the image, would it be practical to place a second LED strip on the opposite edge of the page?

Ant1
Posts: 4
Joined: 28 Jan 2019, 07:41
E-book readers owned: tablet + perfect viewer
Number of books owned: 10000
Country: France

Re: Another book shooter Mk-V

Post by Ant1 » 18 Feb 2019, 07:07

Hi

I have tinkered further during the weekend.
A second LED strip was a complete disaster (lots of glare).
Adding some aluminum tape on the window to reflect some of the light did yield good results.
Here's a pic of my tape :
Image

And here's a pic of a scanned color page :
Image

The lighting is now more even.

Regards,
Ant1

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