PRS-500 RasterFarian 2.5 Beta - Page 12

athlonkmf · 09-05-2007, 04:16 PM

Quote:

Originally Posted by cacapee

Thanks for making a comparison. I didn't add the sharpness filter to pdflrf - but it looks like that does make a difference. Also for file size, try reducing the number of colors.

A file with 4-colors with pdflrf has been made already (and made available in the article), but by reducing the colors, the images are more washed out compared to rasterfarian. It does creates smaller sized files though.

The trick of rasterfarian is not just the sharpness that dilation dpi is huge and it's not simply reducing the colors of an image, it remaps it with the 4-color pallette.
Also, it uses one of the highest-quality image processing tools available, netpbm. I don't know which one pdflrf uses.

I believe you made the sourcecode available at first. You still want to do that? Maybe I can take a look and give you some pointers on where the quality-enhancing stuff are?

cacapee · 09-05-2007, 04:30 PM

Yeah, I looked into the rasterfarian code (old and new) when writing my tool. As far as image processing goes, I'm using CImg (simply because it is easy to integrate). The process goes like this

generate images at 300 dpi
dilate (using CImg)
resize (using Cimg's cubic interpolation)
convert to gif using (libgd)

I believe you are correct in that things can be improved. I was looking at using the lanczos filter to do resizing. Also remapping to the 4-color palette as opposed to using whatever libgd does may be a better thing to do. I'll also add sharpen.

I want to get a stable code base before releasing the source. If you are interested I can add a output-debug-image option that will save out bmps at each step of processing. This is probably more useful to you too.

athlonkmf · 09-05-2007, 04:37 PM

Quote:

Originally Posted by cacapee

Yeah, I looked into the rasterfarian code (old and new) when writing my tool. As far as image processing goes, I'm using CImg (simply because it is easy to integrate). The process goes like this

generate images at 300 dpi
dilate (using CImg)
resize (using Cimg's cubic interpolation)
convert to gif using (libgd)

I believe you are correct in that things can be improved. I was looking at using the lanczos filter to do resizing. Also remapping to the 4-color palette as opposed to using whatever libgd does may be a better thing to do. I'll also add sharpen.

I want to get a stable code base before releasing the source. If you are interested I can add a output-debug-image option that will save out bmps at each step of processing. This is probably more useful to you too.

When I developped my manga2ebook tool I've did a comparison on all available filters of imagemagick too. In a nitpick test I find the catrom-filter to produce the best quality rasterized grayscale images. The lanczos is a good 2nd place though.
You might want to use catrom instead nevertheless.

One of the best thing of rasterfarian is that it uses multiple processes so it can make optimal use of the available processor. That might a be a good idea for you too?

But the reason I'm sticking with rasterfarian must be the TOC-feature. Unfortunately, that is the thing that uses the pdftools which caused the whole ruckus...

Also.. converting the images to png and then using some png-optimizer could give even better result.

jaffer1979 · 09-06-2007, 12:26 AM

So does that mean that the pdfs that I gave you the sample for cannot be done with your tools cacapee?

cacapee · 09-06-2007, 01:09 AM

Hi, I just tested your file and fixed the bug. I'll release the fixed version within the next couple of days.

jaffer1979 · 09-06-2007, 01:25 AM

SWEET!!!!!!! Thanks a bazillion I can't wait to get my hands on it!!!

JSWolf · 09-06-2007, 01:33 AM

Would it be possible to examine a PDF and if you see a page that has a full color image, convert to JPG and not GIF and allow truecolor as an option on the color bits? It seems to me that would give us a better looking image. The Reader does a pretty good job at dithering from a full color image.

athlonkmf · 09-06-2007, 01:55 AM

Quote:

Originally Posted by JSWolf

Would it be possible to examine a PDF and if you see a page that has a full color image, convert to JPG and not GIF and allow truecolor as an option on the color bits? It seems to me that would give us a better looking image. The Reader does a pretty good job at dithering from a full color image.

it's possible, but the size of the lrf will be much larger and the battery will be drained faster.

I've noticed that I can only get like 2000 pageturns when reading manga-lrf on a single charge, but reading normal text I can get 4000, so I assume that rendering the grayscale image takes some extra CPU-power too. Colored images might cause even more powerdrain.

cacapee · 09-06-2007, 02:02 AM

Yes, but it'll make the file size larger. I'll add an option to preserve color.

kovidgoyal · 09-06-2007, 04:58 AM

The advantage if using colored images is that the LRF files are likely to be useful in the future as well when/if SONY releases a color version of the reader.

athlonkmf · 09-06-2007, 05:14 AM

Quote:

Originally Posted by kovidgoyal

The advantage if using colored images is that the LRF files are likely to be useful in the future as well when/if SONY releases a color version of the reader.

It's easier to convert when that actually happens, in like 2 years? By then I probably have a 8-core CPU anyway.
It's not like people would just throw their original books away.

And I really really doubt that by then, there aren't other readers out who're using another format.

kovidgoyal · 09-06-2007, 05:33 AM

Reconverting books endlessly, and in this instance for a completely avoidable reason is a waste of time. And even if a new format is being used, SONY will still provide support for reading LRF files on its readers.

athlonkmf · 09-06-2007, 05:41 AM

Quote:

Originally Posted by kovidgoyal

Reconverting books endlessly, and in this instance for a completely avoidable reason is a waste of time. And even if a new format is being used, SONY will still provide support for reading LRF files on its readers.

The larger an LRF-file in size, the longer it takes to load it up in the sony reader.
I rather waste CPU-time than waste space on my 2GB card. At least I can batch the conversions and it works in the background.

Converting so it can be used on a future device just wouldn't do it for me. And I doubt my future color reader would be a Sony Reader if there are other brands out then. I'd jump ship easily to a brand that doesn't have lrf.

TadW · 09-07-2007, 07:22 AM

Quote:

Originally Posted by cacapee

Hi, I just tested your file and fixed the bug. I'll release the fixed version within the next couple of days.

A great tool getting better and better

pidio · 11-23-2007, 06:38 AM

No files...

11-23-2007, 06:38 AM	#180
pidio Junior Member Posts: 1 Karma: 10 Join Date: Nov 2007 Device: PRS-505	No files... Last edited by pidio; 11-23-2007 at 06:42 AM.

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09-05-2007, 04:30 PM	#167
cacapee Connoisseur Posts: 77 Karma: 1393 Join Date: Aug 2007 Location: Santa Monica Device: prs-500	Yeah, I looked into the rasterfarian code (old and new) when writing my tool. As far as image processing goes, I'm using CImg (simply because it is easy to integrate). The process goes like this generate images at 300 dpi dilate (using CImg) resize (using Cimg's cubic interpolation) convert to gif using (libgd) I believe you are correct in that things can be improved. I was looking at using the lanczos filter to do resizing. Also remapping to the 4-color palette as opposed to using whatever libgd does may be a better thing to do. I'll also add sharpen. I want to get a stable code base before releasing the source. If you are interested I can add a output-debug-image option that will save out bmps at each step of processing. This is probably more useful to you too.

09-06-2007, 12:26 AM	#169
jaffer1979 Enthusiast Posts: 30 Karma: 50 Join Date: Aug 2007 Device: SonyPrs-500/Palm T\|X	So does that mean that the pdfs that I gave you the sample for cannot be done with your tools cacapee?

09-06-2007, 01:09 AM	#170
cacapee Connoisseur Posts: 77 Karma: 1393 Join Date: Aug 2007 Location: Santa Monica Device: prs-500	Hi, I just tested your file and fixed the bug. I'll release the fixed version within the next couple of days.

09-06-2007, 01:25 AM	#171
jaffer1979 Enthusiast Posts: 30 Karma: 50 Join Date: Aug 2007 Device: SonyPrs-500/Palm T\|X	SWEET!!!!!!! Thanks a bazillion I can't wait to get my hands on it!!!

09-06-2007, 01:33 AM	#172
JSWolf Resident Curmudgeon Posts: 73,897 Karma: 128597114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	Would it be possible to examine a PDF and if you see a page that has a full color image, convert to JPG and not GIF and allow truecolor as an option on the color bits? It seems to me that would give us a better looking image. The Reader does a pretty good job at dithering from a full color image.

09-06-2007, 02:02 AM	#174
cacapee Connoisseur Posts: 77 Karma: 1393 Join Date: Aug 2007 Location: Santa Monica Device: prs-500	Yes, but it'll make the file size larger. I'll add an option to preserve color.

09-06-2007, 04:58 AM	#175
kovidgoyal creator of calibre Posts: 43,844 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	The advantage if using colored images is that the LRF files are likely to be useful in the future as well when/if SONY releases a color version of the reader.

09-06-2007, 05:33 AM	#177
kovidgoyal creator of calibre Posts: 43,844 Karma: 22666666 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Reconverting books endlessly, and in this instance for a completely avoidable reason is a waste of time. And even if a new format is being used, SONY will still provide support for reading LRF files on its readers.