Canon DR-G2140

Listing of issues with the Canon DR-G2140. This is MSRP of $9,265.00 and sells for about $7,200-$7,400 as of 2022. This is really designed to scan 70,000 sheets double sided per day, and built like a tank. What's nice is the ease of cleaning and maintaining it. The glass covering the CCDs can be removed and cleaned or replaced if it becomes scratched using nothing more than a bent paper clip. As the glass is an insulator static builds up, and attracts dust to the inside layer of it. In most scanners this is not a serviceable part and you practically have to disassemble the entire scanner to get at it. No so in this.

This was purchased to scan 11x34 at 600 DPI. This claims to support Win7 x64, and while it says this on the docs and website, canon will not support it. This also is suppose to have a network interface, it does, but canon doesn't support scanning via the network. Canon requires USB3 as the interface, and thus the requirement for expensive cables.

Canon Supplied software

Full stop, canon doesn't support any other os the M$. You will need a dedicated VM just for this scanner.

Canon supplies "CaptureOnTouch v4 Pro" with the scanner. This is a single threaded app, and takes quite a bit of time to process. The documentation/online help for this app is poor at best. I had to work with it via trial and error to figure out the settings.

This is claimed to be supported on Win7, but canon support claims it's not. I was able to install and get it working on Win7, and also tried it on win 10 pro.

Long Document Mode

Canon specs say the scanner can capture at 600 dpi in long document mode. This doesn't work in practice.

The issue for long document mode seem to be mostly the poor software support. When you go to select the long document mode, it must be the last thing you do before exiting the configuration dialog. If not, it will reset to non-long document mode. If you open it again and make changes, it will revert to non-long document mode, and even if you go to the long document mode tab, long document will be selected, but not take effect unless the radio button is changed and then changed back.

Of special note here, is the "Image Quality:" selection box on the basic tab. If this is set to Image Quality Priority vs. Speed Priority, the scan will fail at 440 dpi and higher with a long document. Duplex or simplex scan has no effect on it, nor does the Other Tab > "Always transfer compressed images from scanner". If it's long document and greater than 440 DPI, it will fail with an out of memory error.

This error stands on win7 and win10. I've tried 8 and 16 gb of ram with win10 and it fails in either case. I can see no temp file issue or memory constraint.

What is interesting is even though the 64 bit version of the software is installed, it still runs as a 32 bit executable in win10. This means it cannot address >2 (or maybe 4GB if linked with /LARGEADDRESSAWARE) on windows. I'd be wager this is crux of the issue and likely has a 2GB limit of ram, as most old software assumes the top bit of pointers will be 0 on win32. Mind you this is absolute shit programing.

Note there's some overlap/poor separation between the scan processing software and the TWAIN/driver software. The scanning issues where the paper size doesn't stay selected is with the TWAIN driver (which is 64 bits), where as the software running out of memory is due to the software.

Bugs

I've made a video showing the bug in the driver here

This video shows the out of memory issue with the canon CaptureOnTouch v4 software if scanning at >425 DPI and > 11x17 paper size. This also shows the 32 bitness of the application, even though the 64 bit installer was used.

Both these are tracked in Canon Case ID 301-017-5620

Quality compared

I wanted to see the difference of the speed vs. quality setting at 600 DPI. Some of the manuals I'm scanning have 11x17 pages with the same sort of print that's on the longer diagrams. There is a marked difference in speed vs. quality in my opinion. Look at the hashed grey areas on these PCB layouts, it's a huge difference.

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  Speed vs. Quality setting at 600dpi

These are the uncompressed 11x17 source images the above was taken from. Mediawiki (well imagemagik) barfs on making thumbnails) so direct links.

https://wiki.w9cr.net/images/2/27/600dpi_quality_Priority.png

https://wiki.w9cr.net/images/9/99/600dpi_speed_priority.png

https://wiki.w9cr.net/images/1/17/400dpi_quality_priority.png

https://wiki.w9cr.net/images/2/2e/400dpi_speed_priority.png

IMHO, the difference is night and day.

Good Points

So the ability to scan a ream of paper very fast, and even yellowed books, the total lack of feed problems (I've yet to have a mis-feed) and general build quality is good. Like most things the software sucks ass.

Thoughts

since the software is what's crashing/runing of of memory I did consider trying something called vuescan, but while it claims this scanner is supported, it doesn't work. The author did write me back and say he didn't test it and will look into it.

Perhaps I can find another software what will work on windows.