10-25-2010, 05:03 PM | #1 |
Enthusiast
Posts: 43
Karma: 2188
Join Date: Jan 2010
Location: Kharkov, Ukraine
Device: lbook V3, iRex DR800SG
|
Is it possible to reduce display colour depth?
Some low-contrast scanned texts are hardly readable due to the relatively high colour depth supported by DR800. My question is to the reader software gurus: can it not be adjusted somehow for PDF's and DjVu's? Thanks!
|
10-26-2010, 01:05 PM | #2 |
Nameless Being
|
i'm afraid nobody from the old-IREX crew will read your problem and certainly not helping out. That's what happens when a company get busted. Unfortunately it is like it is. I'm still very glad to have the DR800SG and reading on it is a pleasure.
Hopefully some of the users can help you out. |
Advert | |
|
10-26-2010, 02:28 PM | #3 | |
Wizard
Posts: 4,293
Karma: 529619
Join Date: May 2007
Device: iRex iLiad, DR800SG
|
Quote:
Regarding the original question, I assume by "color depth" you're referring to the shades of grey that the display is interpreting from the PDF? I don't think it's really a DR800 question, but rather whether or not there are any software applications that will let you darken a PDF document. I assume these are being scanned as images, and not OCR'd into text? |
|
10-26-2010, 03:56 PM | #4 |
Enthusiast
Posts: 43
Karma: 2188
Join Date: Jan 2010
Location: Kharkov, Ukraine
Device: lbook V3, iRex DR800SG
|
Correct, I meant files without OCR. Thank you for your advice - I'm currently looking for such applications. Just wondered if the reader's software offered a way to reduce/restore the number of displayed colors (by running a script or something like this).
|
10-26-2010, 07:37 PM | #5 | |
Wizard
Posts: 4,293
Karma: 529619
Join Date: May 2007
Device: iRex iLiad, DR800SG
|
Quote:
Technically, I think a PDF full of images can probably be extracted out into individual JPG/GIF/etc files (whatever format it uses internally). You could then use whatever paintshop type program to darken them, and then recombine into a PDF again. There are probably tools that make all of that a lot easier though, but I'm not an expert on them (obviously). |
|
Advert | |
|
02-04-2011, 05:48 PM | #6 |
Enthusiast
Posts: 43
Karma: 2188
Join Date: Jan 2010
Location: Kharkov, Ukraine
Device: lbook V3, iRex DR800SG
|
significantly enhanced contrast for djvu files
A nice improvement has been made to Pocketbook DJVU reader by review:
https://www.mobileread.com/forums/showthread.php?t=119874 Maybe, some of our glorious developers will be interested to make this improvement for Irex, too? Here is the direction from review: https://www.mobileread.com/forums/sho...0&postcount=19 Thanks for all you've done, guys! |
02-04-2011, 06:29 PM | #7 |
Addict
Posts: 326
Karma: 6908
Join Date: Sep 2010
Device: DRs, EE, ipad/iphone, Helix
|
I think that the experts that have ported the djvu reader for the DR's are luite and also, more recently, yuri_b ...
|
02-06-2011, 03:46 AM | #8 |
Connoisseur
Posts: 71
Karma: 592
Join Date: Aug 2010
Device: irex dr800sg DR1000S
|
We are using FORMAT_GREY8 that gets 256 grey levels, that can be converted to 4 byte gray level.
What he suggest is convert image to white black 2 colors, and this IMHO not good, because I'd like see also images in books, not only text. Sincerely Yura |
02-07-2011, 01:40 PM | #9 |
Enthusiast
Posts: 43
Karma: 2188
Join Date: Jan 2010
Location: Kharkov, Ukraine
Device: lbook V3, iRex DR800SG
|
Yura,
I see your point, but maybe it would be possible to make the djvu viewer suggesting gray-level options when a djvu file is opened? I saw a lot of texts that looked pale with the 256 greys, but might be more readable with 4 grey level on. What do you think? |
02-07-2011, 01:51 PM | #10 |
Connoisseur
Posts: 71
Karma: 592
Join Date: Aug 2010
Device: irex dr800sg DR1000S
|
Irex E-Ink display is 4-bits grey, so what you see is 16 colors image. If we will convert it straightforward to 2 level black/white it not always will enhance image quality, better will be to use algorithm for enhancing contrast.
The problem: processor used in IREX ebook (and actually in every ebook) not designed for heavy image manipulation, it's too week. Better approach would be offline enhancement of djvu book using more advanced tools for it. In sources of djvu plugin I see that luite tried to enhance image by converting it to 4-bits before display. This code in comments, maybe something not work as expected, or his algorithm too slow. Sincerely Yura |
02-07-2011, 02:38 PM | #11 | |
The Windlord
Posts: 119
Karma: 10
Join Date: Jun 2009
Location: Netherlands
Device: iRex DR1000S, BeBook Club S
|
Quote:
In short: if at all possible, I'd try to solve this problem at the source, at the scanner. |
|
02-07-2011, 05:01 PM | #12 |
Addict
Posts: 326
Karma: 6908
Join Date: Sep 2010
Device: DRs, EE, ipad/iphone, Helix
|
there is a rather detailed discussion of djvu in message #3 of this post
https://www.mobileread.com/forums/sho...te#post1154480 that might (or not) be relevant to this post here ... |
Tags |
color depth, contrast, djvu |
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
RTF tip - Instantly reduce filesize by 40% | garbanzo | Other formats | 10 | 03-21-2011 04:19 AM |
Classic Reduce wide margin and installing own fonts? | Barty | Barnes & Noble NOOK | 0 | 10-18-2010 02:40 PM |
This is how I reduce the font in a lrf file | grimborg | Calibre | 0 | 11-02-2009 07:39 AM |
Reduce "black display" when turning page? | Juggle4Evr | Sony Reader | 2 | 11-20-2008 05:02 PM |
KDDI Develops Colour, Wireless, E-Paper Display | jonbaber | News | 3 | 10-17-2008 01:37 AM |