MobileRead Forums - View Single Post - iLiad Introducing the new Sony-Reader-speed ipdf

Matthijs · 10-27-2006, 03:48 AM

This looks very interesting, however:

The reason why we stuck to RGB rendering (yes, we did try this Mono8 too) is that now images inside the PDF document that were in color will look ugly (they show 'banding', take a look at the first page of the iLiad User Manual for an example).

If this dithering inside libpoppler can be fixed, we can have another look at this approach.

It was also reported by one of our engineers that some of the smaller fonts actually look LESS sharp in 8bit grey. But that is of course hard to compare with only 1 iLiad...

As for the speed: going from page to page uses pre-rendering and is not affected by the changes above. Only the actual rendering of pages uses more memory and is slower in 'our' implementation, but pushing the resulting XImage to the screen (which is all that is done when a page is flipped) is equally fast. Startup time of the viewer and rendering of a page that is not pre-rendered is faster of course.

In summary: there are outstanding problems to be fixed. Dithering of color-images in Mono8 mode in libpoppler needs adjustment for the iLiad color-space, that is a very important one.

We really hope that by working together with the community on these kind of things, we can bring the iLiad software to the next level even faster.

Thank you all for contributing, please continue to do so.

Matthijs van de Water
Embedded Software Engineer
iRex Technologies BV

10-27-2006, 03:48 AM	#23
Matthijs Groupie Posts: 199 Karma: 666 Join Date: Oct 2006 Location: Eindhoven, the Netherlands Device: iLiad, DR1000S, DR800SG	There is always a but... This looks very interesting, however: The reason why we stuck to RGB rendering (yes, we did try this Mono8 too) is that now images inside the PDF document that were in color will look ugly (they show 'banding', take a look at the first page of the iLiad User Manual for an example). If this dithering inside libpoppler can be fixed, we can have another look at this approach. It was also reported by one of our engineers that some of the smaller fonts actually look LESS sharp in 8bit grey. But that is of course hard to compare with only 1 iLiad... As for the speed: going from page to page uses pre-rendering and is not affected by the changes above. Only the actual rendering of pages uses more memory and is slower in 'our' implementation, but pushing the resulting XImage to the screen (which is all that is done when a page is flipped) is equally fast. Startup time of the viewer and rendering of a page that is not pre-rendered is faster of course. In summary: there are outstanding problems to be fixed. Dithering of color-images in Mono8 mode in libpoppler needs adjustment for the iLiad color-space, that is a very important one. We really hope that by working together with the community on these kind of things, we can bring the iLiad software to the next level even faster. Thank you all for contributing, please continue to do so. Matthijs van de Water Embedded Software Engineer iRex Technologies BV Last edited by Matthijs; 10-27-2006 at 03:51 AM.