Search found 85 matches

by rkomar
03 Jan 2017, 21:59
Forum: Cameras and Electronics
Topic: Dire camera situation 2017
Replies: 11
Views: 363

Re: Dire camera situation 2017

I haven't bought a camera for a few years, so I'm out of date. What are the Canon cameras using if PTP is disabled? WiFi?
by rkomar
22 Dec 2016, 21:38
Forum: Scanners and Build Threads
Topic: My DIY Scanner
Replies: 31
Views: 567

Re: My DIY Scanner

It's not that easy to optimize the zoom value for different sized books because the center of the page on the platen moves as the book changes size. If you want to cut down on wasted picture area, you have to be able to move the camera up and down to position it over the center of the current page. ...
by rkomar
22 Dec 2016, 19:19
Forum: Scanners and Build Threads
Topic: My DIY Scanner
Replies: 31
Views: 567

Re: My DIY Scanner

I wasn't suggesting to use chdkptp for scanning books, but rather to use it to search for the optimum values for the focus distance, zoom and exposure time. Once you have those values, hopefully you can pass them to whatever software is doing the scanning. Personally, I don't trust the camera to get...
by rkomar
19 Dec 2016, 23:35
Forum: Scanners and Build Threads
Topic: My DIY Scanner
Replies: 31
Views: 567

Re: My DIY Scanner

Nice work, and thanks for sharing! Since your cameras are always at the same position, I'd try to lock the focus and zoom to the same position every time. I'm assuming that you are using CHDK to control the cameras. You can use chdkptp to set different focus points and zoom levels to see which one p...
by rkomar
07 Dec 2016, 16:21
Forum: "Destructive" Scanning
Topic: ix500 workflow. Scan directly to grayscale/bw or do it in photoshop postprocessing?
Replies: 21
Views: 326

Re: ix500 workflow. Scan directly to grayscale/bw or do it in photoshop postprocessing?

There is a small advantage to scanning in colour; you can define yourself how the conversion from colour to greyscale is done. It's theoretically possible that different colours will produce the same greyscale value in one conversion scheme, thereby looking the same in the output. A different scheme...
by rkomar
03 Dec 2016, 22:04
Forum: Scanners and Build Threads
Topic: Best non-DIY book scanners
Replies: 36
Views: 17727

Re: Best non-DIY book scanners

I'm a linux guy, so I use command-line programs with shell scripts to convert images. I mentioned earlier that I use the binarizewolfjolion program to convert from greyscale to black-and-white. I use unpaper to clean up images. I also use ImageMagick and the netpbm suite of programs to do general co...
by rkomar
03 Dec 2016, 21:10
Forum: Scanners and Build Threads
Topic: Best non-DIY book scanners
Replies: 36
Views: 17727

Re: Best non-DIY book scanners

I think it partly depends on what you intend to read the scanned books on. I read on an E-Ink device, which has low contrast, so converting to black-and-white improves the readability and speed greatly. If reading on an LCD screen, then grayscale looks better than black-and-white. Personally, I woul...
by rkomar
01 Dec 2016, 22:02
Forum: Scanners and Build Threads
Topic: Best non-DIY book scanners
Replies: 36
Views: 17727

Re: Best non-DIY book scanners

Ouch! That's a lot of money for half a year of scanning. I hope you can get it fixed.
by rkomar
01 Dec 2016, 04:19
Forum: Scanners and Build Threads
Topic: Best non-DIY book scanners
Replies: 36
Views: 17727

Re: Best non-DIY book scanners

I would add that, for acid-paper, scanning with the Plustek in black and white can produce a lot of noise if the pages are becoming brown. It appears that the scanner software just does a simple thresholding calculation when binarizing the output file. I got much better results when I scanned in gre...
by rkomar
30 Mar 2016, 18:47
Forum: Cameras and Electronics
Topic: Problem with the other camera not focusing properly
Replies: 4
Views: 893

Re: Problem with the other camera not focusing properly

For a fixed geometry, you might try taking a series of pictures at different focal lengths, see which looks the best, and then always set the focal length to that value and lock it prior to each session. Relying on autofocus is hit and miss, depending on what is being photographed.

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