Single camera - "wrong" side pages flip back

[nightshift]

Help!

Working with a modified version of the cardboard box scanner - I needed a larger cradle to support academic sized books, although I did overestimate the size I needed - but, I did do the math to keep the cradle angle the same. I'm having a problem where the "wrong" (not currently being scanned) side pages are flipping or curling back over the platen resulting in obscured images when I have the platten glass placed as deep in to the spine as possible. I can force the pages flat against the other side of the cradle by adjusting the angle of the platen (a different angle every time).

Example photos using a fairly thin and small perfect bound paper back, but is also happens with larger hard backs.

[cday]

I can force the pages flat against the other side of the cradle by adjusting the angle of the platen (a different angle every time).

Do you mean that you can't force the pages flat against the other side of the cradle?

[BillGill]

If I understand correctly in your set up the platen presses against only one page of the book and the opposite page is not restrained. So the opposite page can flop over into the view of the camera. So what you need is a way to hold the opposite page back. There could be a number of ways to hold it back, anything from a rubber band across the opposite page to a frame that holds it back. It shouldn't be too difficult to come up with something. I know in my KISS scanner I had to add a strip across the open side of the frame to keep from having this problem. I'm afraid I would have to see the setup to be able to come up with a concrete fix. Nah! concrete would be too heavy.

Bill

[nightshift]

I can force the pages flat against the other side of the cradle by adjusting the angle of the platen (a different angle every time).

Do you mean that you can't force the pages flat against the other side of the cradle?

No, as illustrated in the second photo, if I adjust the angle of the glass, so that it is no long parallel with the cradle with the "inside" edge riding up the opposite page, I can sometimes force that opposite page flat enough to get a clean scan. (My second photo those pages are still floating a bit, but, they are far enough back to get an ok scan)

[nightshift]

I'm afraid I would have to see the setup to be able to come up with a concrete fix. Nah! concrete would be too heavy.

Bill

You're right, concrete would be too heavy!

My setup is basically Daniel's cardboard box https://www.instructables.com/Bargain-P ... board-Box/ scanner. I increased the dimensions so the cradle could fully support up to a 14" tall by 12" wide book, and built each box half out of foam core board. I also added a base "frame" out of double layer cardboard so I wouldn't have to tape down to the table and give up the use of that table until I've finished all my scans. I can get a picture of my actual set up later.

[nightshift]

Ok, here is the photo of my complete set-up (minus the camera on the tripod).

I'm thinking about some sort of weight anchored to the back of the left wedge - maybe an inexpensive ruler/straight edge or some sort of straping that could be flipped up and down. Would further reduce the ergonomics (right now my shutter remote is a USB cord to a USB charger brick plugged in to a power strip that is plugged in to the wall - power strip gets turned on and back off to take picture) and speed, but, maybe I'd get usable images?

[cday]

Would placing a spacer of some kind possibly help with keeping the page not being scanned out of the wanted view area?

[BillGill]

You seem to have the right idea about how to keep the page out of the view of the camera. You can fix some kind of strap to the back side of the left wedge with a thin weight to hold the page flat. I'm not sure a ruler would be heavy enough but you should be able to find something around that is flat and still heavy enough to hold the page flat.

Now to another thing about your scanner. Not for the scanner itself, but for processing after the scan is complete. It looks to me as though you are going to wind up with alternate pages upside down. That is left hand pages will have the header towards you and right hand pages will have the header away from you. You will probably have to do some processing to get them all right side up. You can use GIMP (GNU Image Manipulation Program) to get them the right way, but you will have to have the right and left pages in separate directories. So you may have to photograph all of the pages on one side at a time, then take all of the other pages separately. After that you can use a utility such as Bulk Rename Utility to get them in the correct order.

I know this takes more time, but you will wind up with a nicely sorted and oriented.

Good luck
Bill

[nightshift]

Would placing a spacer of some kind possibly help with keeping the page not being scanned out of the wanted view area?

I tried a spacer of various sizes, didn't help much (did a complete "test" scan of the small book used to illustrate the problem, maybe 1/8th of the pages were remotely usable), so, I need something to hold them down, not prop the cover up.

You seem to have the right idea about how to keep the page out of the view of the camera. You can fix some kind of strap to the back side of the left wedge with a thin weight to hold the page flat. I'm not sure a ruler would be heavy enough but you should be able to find something around that is flat and still heavy enough to hold the page flat.

Now to another thing about your scanner. Not for the scanner itself, but for processing after the scan is complete. It looks to me as though you are going to wind up with alternate pages upside down. That is left hand pages will have the header towards you and right hand pages will have the header away from you. You will probably have to do some processing to get them all right side up. You can use GIMP (GNU Image Manipulation Program) to get them the right way, but you will have to have the right and left pages in separate directories. So you may have to photograph all of the pages on one side at a time, then take all of the other pages separately. After that you can use a utility such as Bulk Rename Utility to get them in the correct order.

About the ruler, I think you are right. I might have to take a stroll through the hardware and farm stores and see what I can find. I also want to test a thought I had. One of my modifications was to create spine width spacers (and dead space fillers) that were meant to keep the right wedge in place for different sized books (the the full setup photo, that is why the right wedge isn't taped to the cardboard and there seems to be some cardboard popping out behind it). I'm wondering if removing the spine wedge would let the spine drop/settle a little deeper into the cradle and hold it in place better.

As to the having the left pages upside down, you are right, they will be. Scan tailor advanced can handle the rotation and it looks like it can handle reordering and maybe even renaming - couldn't test beyond rotation because reorder and rename (if possible) depend on being able to identify the page in the "split page" tab and I didn't have enough pages with a clear enough split to test it. I'll take a look at Bulk Rename just in case scan tailor can't rename, but at my first glance it was windows only. I'm on Linux. Worst case I could probably write a simple script myself - it'll help that I have my camera set to reset the file names every time I take the card out and put it back in (assuming I'm understanding what they meant on that, it may only work when you actually change the card for a different one, not a wholly impossible task, ive got extra SD cards and smaller ones are cheap when you can find them).

[cday]

Would placing a spacer of some kind possibly help with keeping the page not being scanned out of the wanted view area?

I tried a spacer of various sizes, didn't help much (did a complete "test" scan of the small book used to illustrate the problem, maybe 1/8th of the pages were remotely usable), so, I need something to hold them down, not prop the cover up.

I was also thinking that a spacer could assist in keeping any hold-down device you use out of the wanted view area. Probably obvious...

I'm on Linux...

If you need cross-platform software for image editing and renumbering files and aren't already familiar with Gimp, you might look at XnView MP and the associated NConvert command line software, also XnConvert as a standalone batch image processing software, probably easier interfaces to learn than Gimp. Declaration: I am a moderator although not shown as such on that forum too, but have no financial interest in the software...