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

Footsie Bookscanner

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.
wmalcolmk
Posts: 24
Joined: 12 May 2015, 04:39
Number of books owned: 500
Country: England

Re: Footsie Bookscanner

Post by wmalcolmk » 14 Jun 2015, 12:37

Footsie Photos

Here at last are photos of the complete structure, including screening from
overhead lighting in the room, and support for the book lamp.
Footsie1.JPG
Footsie1.JPG (16.99 KiB) Viewed 2558 times
The overall height is 1.55 metres, and width and depth are 0.6 metres (excluding foot pedal). The operator pushes down the foot pedal and guides the book upto the platen with his/her hands. Seat height needs to be above the norm for eating at a table, with elbows/arms at 0.9 metres when the book is in contact with the platen. As can be seen from the next photo of the rear of the structure, there is a fabric screen held on with velcro fastenings, and in this case a portable workbench is used as the main support. However a table or shelf screwed to the wall could also be used.
Footsie2.JPG
Footsie2.JPG (17.26 KiB) Viewed 2558 times
The cameras view the platen through portholes in the screen. This makes set up and adjustments very easy to carry out.
Porthole.JPG
Porthole.JPG (21.91 KiB) Viewed 2558 times
The LED lighting strip is a separate removeable assembly, made from aluminium angle with glue-on led 12 volt strip lights.
Led Strip1.JPG
Led Strip1.JPG (18.25 KiB) Viewed 2558 times
Next Steps

Although the work to date proves in principle that there are advantages in holding the platen stationary and moving the book up to the platen, I still need to put more work into developing a fully functional scanner.

The tasks I plan to do next are...

1. Install CHDK in the cameras and automate remote zoom/focus/shutter release.
2. Supply power to the cameras to avoid battery problems.
3. Investigate different LED strips in terms of light intensity, evenness and colour temperature.
4. Develop post processing techniques.

I intend to stop putting up reports until I have made significant progress in these tasks. However I will try to answer any questions that come up, and if anyone in the Cambridge England area takes up these ideas, I am prepared to help with the supply of parts that prove difficult to source or make.

I hope you found my quirky ideas of interest - Malcolm

duerig
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Country: United States of America

Re: Footsie Bookscanner

Post by duerig » 14 Jun 2015, 16:37

There are a lot of interesting ideas here, and I appreciate you showing your progress. Please post sample scans and also scans of blank paper so we can see what your setup can do.

You might want to check out Spreads for your camera control and capture. What kinds of post processing software do you plan on writing?

-D

Marcus Eastty
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Country: United States

Re: Footsie Bookscanner

Post by Marcus Eastty » 14 Jun 2015, 23:39

Thanks for taking the time to show the photos of the book holder. In builds where the platen drops into the book, the cradle typically adjusts to accomodate the width of the book. Is this not necessary in this case? I envision the book coming up to the platen and finding the groove into the gutter pretty easily, but it is a thought I had.

All of the updates, additional photos, build progress, etc. is really helpful for newbies such as myself, so again, thank you.

wmalcolmk
Posts: 24
Joined: 12 May 2015, 04:39
Number of books owned: 500
Country: England

Re: Footsie Bookscanner

Post by wmalcolmk » 15 Jun 2015, 06:00

Marcus asked the question..

In builds where the platen drops into the book, the cradle typically adjusts to accomodate the width of the book. Is this not necessary in this case?

Answer - Yes, it is necessary that the book is adjusted sideways as the pages are turned. In this case it is done by sliding the cradle relative to the rope. It happens gradually by the movements of the hands as they guide the book up to the platen. I find that with pages that aren't slippery, a slight 'jiggle' of the book helps to ensure that it seats neatly in the glass vee. I would be interested to know if there are any signs of miss-seating in the vee with other designs.

Malcolm

wmalcolmk
Posts: 24
Joined: 12 May 2015, 04:39
Number of books owned: 500
Country: England

Re: Footsie Bookscanner

Post by wmalcolmk » 15 Jun 2015, 10:39

First Test Photos

duerig asked for sample scans. These cannot be regarded as more than first tests to find out what needs attention. They have had some manipulation in the computer in order to reduce file size mainly. I am using cool LED arrays, since I am concentrating on black and white reproduction at first. As a result, the camera is working in B&W mode.
This first is a blank white paper scan which shows evidence of ghost images of the internal structure of the scanner. I propose to paint the inside matt black to eliminate this effect. I think the lighting system is sufficiently even for my current purposes.
Blank1.JPG
Blank1.JPG (14.24 KiB) Viewed 2521 times
Here is a cropped photo of a coloured page. The curved top to the image indicates that I need to take greater care with camera alignment. The text looks as if it could be acceptable to OCR software. I have minimal experience in this area. Any advice?
Test1.JPG
Test1.JPG (61.6 KiB) Viewed 2521 times
Just to show how strong a blue cast the LEDs produce, here is an uncorrected colour shot, and the result after correction attempts using Picasa.
Blue1.JPG
Blue1.JPG (55.83 KiB) Viewed 2521 times
Blue2.JPG
Blue2.JPG (61.03 KiB) Viewed 2521 times
In answer to the other comments from duerig - I will check out Spreads, but hope to use existing post processing software. However I am on a steep learning curve in this area.

Malcolm

dpc
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Re: Footsie Bookscanner

Post by dpc » 15 Jun 2015, 15:23

Regarding the blue tint, check your camera's white balance settings.

The lighting is uneven across your page. It's pretty hot on the page's outside edge and falls off as you move toward the gutter. This is common with the "v" shaped platen scanners and the 1/d^2 falloff of the light source. If you look at the blank page image using the Archivist scanner it also has this problem but it doesn't appear to be as bad as in the image you've posted. I had the idea at one time to use a translucent gradient barn door for the light so that light hitting the outside page edge would be muted somewhat and closer to the gutter it would be transparent and get full light. I never did anything with this though and just shoot a blank page and then post-process the scanned pages based on that page assumed to be white.

It might be helpful if you posted full unprocessed images from your camera. If you're worried about the file size, upload to imgur.com and link to it in your posts.

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jck57
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Re: Footsie Bookscanner

Post by jck57 » 16 Jun 2015, 19:28

For the support under the book, I think you could do away with all the rigid bits and hold the book in sort of sling made of fabric. I imagine the sling held by two arms that pivot together like David's platen-raising mechanism. An adjustable counter-weight would be nice to accommodate books of different weights.

wmalcolmk
Posts: 24
Joined: 12 May 2015, 04:39
Number of books owned: 500
Country: England

Re: Footsie Bookscanner

Post by wmalcolmk » 17 Jun 2015, 03:07

Answering jck57 - I did initialy think of a fabric sling, but couldn't make it press the book or leaflet evenly up against the platen. Your idea of using two arms and a counterweight is well worth trying.

Malcolm

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jck57
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Re: Footsie Bookscanner

Post by jck57 » 17 Jun 2015, 13:34

Another idea: If you get the book perfectly counterbalanced, you could keep one hand under the book/sling to raise it to and lower it from the fixed platen. Your hand passes through a strap attached to the sling in order to "pull" the book away from the platen. The free hand flips pages and presses the electric button for firing the cameras. Nothing like the hand for positioning the book and applying just enough pressure to the platen.

wmalcolmk
Posts: 24
Joined: 12 May 2015, 04:39
Number of books owned: 500
Country: England

Re: Footsie Bookscanner

Post by wmalcolmk » 18 Jun 2015, 13:27

These ideas would avoid the complications of foot pedals, but might make the structure larger at the rear. However, I hope someone can explore these possibilities. At the moment I am concentrating on lighting, cameras and post processing. Here is an unretouched shot with cool leds replaced by warm white leds.
WarmWLeds.JPG
Malcolm

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