Intel new reader

[daniel_reetz]

I've scanned zero paperbacks. What, in your estimation, is the average inner margin distance? How big could an obscuring element be?

[StevePoling]

My diagramming skills suck. Nevertheless, I did create a 2D diagram showing what i am proposing. It suffers from exactly the problem of the inner margin.

For me, the most problematic area of the book is the inner margin. If I tried to scan many pocket-sized paperbacks, it would be difficult to do without cutting off letters there.

Let's see if this shows up:


This stylized figure shows a side-view along the spine of the book. The large green triangles on the sides represent the cradle. The smaller green triangle represents as a wedge that has been lifted temporarily. The two black curves represent two pages that are not lying flat. The gameplan is to weight the smaller green triangle enough to pinch the pages exactly where they curve most against the cradle.

Depending on the book, you might have wider or narrower wedges. That inner margin constraint's a beech. I just checked a paperback novel I want to scan and it'd require a wedge of 5/16" at its widest. I just checked a hard-backed book and it would need a beefier wedge less than 3/4" wide.

This wedge would have to be uber-stiff to apply a spreading force equally up and down the book. If I don't talk myself out of trying this, I may have a candidate for http://thereifixedit.com/

[daniel_reetz]

Seems to me that the #1 benefit of this approach would be... no reflections to deal with. That is so attractive to me that I think I might try to prototype something real soon. Any progress, Steve?

[StevePoling]

Sorry to let you down, Dan, I've gotten distracted with other stuff. Fan died in my laptop, had to move files to a loaner running Windows7 and install everything there.

So, I've got a pile of bits and pieces I'm slowly adding to. If I don't have to drive to Ohio tomorrow, I'll be able to give it some time.

[Randomlaughter]

This isn't exactly portable or power efficient but a strong fan or weak leaf blower would hold the pages flat (assuming they weren't fragile) without getting anything in the image.

[StevePoling]

Any progress, Steve?

Why, yes. I have had some progress. Here's what I've found.

I do have to apply significant downward force (approximately 3lbs). A hardwood dowel (square) seems to work OK

Did you notice the page on the right curling up? That wouldn't have happened if I'd built a platen.

You might be curious about how I'm holding the far side of the dowel down:

(I added the red duct tape to increase contrast.)

There is a problem of the edges of the page curling up and obscuring the opposite page (or maybe I should aim the camera better).


4) Nevertheless, the other page image doesn't seem too bad (if you like nude descending a staircase).


Note the dowel is clearly visible at the bottom of the page. I proposed painting this a "distinctive color" to do something like chroma-key post-processing of the image. But I wonder if I could just paint it white and ignore the problem.

Next time I go downstairs, I'll have to photo the book Edge-On to show how even the dowel doesn't completely flatten the pages.

This book may be a bad example. It has some water damage that has riffled the pages. And the margins may be too generous.

Should I address the page curling issue?

[StevePoling]

By the bye, I have a couple more pictures here. http://www.flickr.com/photos/45236934@N02/

I promise to document things better and put together a separate build thread.

[daniel_reetz]

Steve, this looks great! By coincidence, I noticed this product this morning, which has a related idea: http://www.thumbthing.com/

I think the page curling issue is no big deal -- with just a little camera skew you could have it covered. I mean, a plane-parallel camera is best in theory, but in practice, it seems we all have slightly skewed images.

This book may be a bad example. It has some water damage that has riffled the pages. And the margins may be too generous.

Actually, that probably makes it a great example.

I promise to document things better and put together a separate build thread.

You know me too well! I can't wait for StevePoling's build thread.

I really think this platen-less approach has some real promise. I did some work on a copystand while at my parents house that taught me some new things. I'll share as soon as my brother sends the pics.

[StevePoling]

Thanks for your kind words. I think I can say definitely that my idea won't work...on some books. Worst result: a Bible, because it has many very thin high-quality slippery pages. It was a disaster. The paper slumped and sort of "flowed" over the dowel. To work, the pages need sufficient stiffness.

I tried a very thick book, 1190 pages. Also without joy. I suspect I need to learn how to support the spine of the book better. Applying pressure on the dowel sort of jams the book down into the v-shaped-thingie and if the spine were supported better, it might fight the dowel less and open the pages more. Has anyone figured out the best way to support book spines?

Pulp fiction paperbacks (aka penny dreadfuls) have stiff bindings and excruciatingly narrow gutters. A pair of thumb things extending to the end of the page on both top and bottom might help, but the middles of the page would doubtless curve inwards.

That said, on some books it appears to be just dandy on the handful of pages I've photographed manually. For instance, hardcover books of a couple hundred pages appear to work very well. The critical factor is that the book's gutter be wide enough.

The page curling issue is probably solved by something like the "thumb thing." If we use a "chroma-key" trick to subtract out the thumb thing and replace the square dowel with a stiff metal (?carbon fiber?) rod, we can probably increase the number of books suitable for platen-less scanning.

I can't wait until I get my camera mounts built. I won't have a vibration issue when in platen-less operation. Nevertheless, I intend to mitigate vibration by shortening the threaded rods. I intend to make the majority of the camera mount from 2x4 (salvaged from my brother's basement) with just the threaded rods poking out the ends. With the cameras mounted, I'll be able to see whether platen-less operation can work for a whole book.

[StevePoling]

Here are a few more pictures of platen-less operation.

This image shows what is going on with the binding when I've applied downward force to the dowel holding the pages open and (we hope) flat. From above:

From beneath:


This picture shows the binding of a trade paperback. It shows the need to support the binding.


This shows the dowel holding open a penny dreadful. The gutter is significantly narrower than the dowel. And the page edges need to be held down with something like a thumb thingie.


This shows a narrow hardcover book that just barely has a wide enough gutter. With all the footnotes and old fashioned typeface, this book should prove a challenge to OCR.