For a while I've been busy determining the 'best' resolution for pictures, pdf documents, and lrf files.
The determining of the resolution could help improve image quality and battery life,and reduce filesize and loadtime at the same time;as well as prevent pictures to be stretched or misshaped.
The theory behind it is that any picture which has different dimensions needs to be
resized in order to fit the PRS-505's screen.
Be it enlarged,or made smaller. This costs computing power,and therefor batterylife and time.
The aim of this thread is to find a 1:1 resolution, that the (hardware) reader does not need to stretch or shrink to fit the screen.
To prevent shrinking or stretching, one could already create files custom tailored for the Sony reader. So far I'm working out a matrix. Still a lot of info needs to be inputted.
I've done extensive testing on my PRS-505 and so far I've found the following info: (best and other advised resolutions):
1-Portrait pictures: BEST RESOLUTION=
600x767Pix.
(S)=Small, (M)=Medium, (L)=LArge zoom.
(S)- 600x767
(M)- 900x1050; 450x525; 300x350; 180x210
(L)- 1200x1534; 600x767;
2-Landscape pictures: BEST RESOLUTION=
800x567Pix.
(S)=Small, (M)=Medium, (L)=LArge zoom.
(S)- 800x567
(M)- 1200x850; 600x425; 240x170
(L)- 1600x1134; 800x567
3-PDF Portrait: Still under investigation
377x277
4-PDF Landscape: Still under investigation
5-Picture in LRF: Still under investigation
Book Cover:
In Document:
(S)-
(M)-
(L)-
Any help will be appreciated!
Side note:
On PDF, the best resolution I found to today is 377x277.
Any higher and the PRS uses interpolation.
I tried 754x554, which is to double the tested resolution, but somehow the higher resolution image still gets interpolated. I still need more testing to figure out the 'best' resolutions for PDF and LRF documents.
Formats for comic books
Black and white anime can best be converted to monochrome GIF images.
If you don't posses graphic tools, but only have Windows,I'd recommend you to save the pictures with the desired resolution of above in Paint, and save them as a monochrome BMP. Then later save it to GIF.
If you save the image directly as a GIF file, it will be saved as a 256color (8bit color) GIF instead of a mono (1bit) gif,and the filesize will be larger,and loadtimes longer on the reader.
Any colored anime/comic book, especially 3D animated or with shadow effects are best converted to JPG.
Any anime books with little shadows and details; or any 4color comic books (like pictures included in attachment), probably is better converted to GIF. If you can save only to 256color GIF you may want to read below.
I would recommend ACDSee free version for batch processing (converting any image format to GIF or JPEG).
I would recommend editing pictures in BMP fileformat, and as the last possible action convert it to Jpeg when needed. JPeg is a lossy codec,that will create artifacts. It is best to have as little artifacts as possible in the pictures.
When saving an image to 8bit GIF (256Colors),and don't have or want any editing tools installed on your pc, try saving the picture as a 24bit BMP in paint. Then save it as a GIF.
You'll notice artifacts appearing (rendering).
then in paint click "edit">>"Paste from",and select the 24bit BMP you just saved.
Paste the 24bit BMP over the gif, and save it as a second copy.
Test both images on the reader,and keep the most appealing.
The advantage with the second version of the GIF is, that the rendering will be removed, and colors will be rounded off to their nearest 8bit color equivalent.
This should save you a kilobyte or two per file.
Because the Sony Reader does not show colors,I think the 256 color GIF with rendering artifacts will be better for (Low quality/low color) anime and comic books on the reader.
YMMV though.
Pictures inside LRF
When creating an LRF file, I noted that pictures are not displayed above a certain resolution (further to be determined). I also noted that it is best to save those pictures as Jpeg with a good editing software,and then parse them (or insert them) inside an LRF.
Any non-.jpg picture (.png, .gif, .tiff, .bmp) will automatically be converted in BD to jpeg,with loss of quality.
It seems MS paint saves Jpegs way better than BD. I can not speak of other programs but assume Calibre also saves pictures to jpeg inside an LRF.
Images loaded in LRF are generally lower than 600x758; much lower (still to be determined exactly how low), and therefor having a comic book in LRF is not really recommended.
First picture JPeg; Third picture dirthered GIF; Fourth picture overlayed GIF(no dirthering)
The .rar file can be opened with winrar. Program at
www.rarlab.com. it contains grid images for testing.