Where is the "full resolution" button?
My test were with out changing any settings.
My mistake. The actual terminology on the button is "Original Size" (see image). An image with an original size of 1024 x 768 will fill the page at "Original Size". It would appear the default size is that of the iPad 1 and iPad 2. I still think some clairfication is in order. (Perhaps a Retina Size button?)
>then opened the package and looked at the assets.
Are you familiar with 'pngcrush'...? Xcode provides it as an option when buidling app binaries and I suspect Preview as well, when saving and reducing file size. iBA itself has possessed the (dormant till now) @2x scheme capability for certain supplied icons since it came out, as well.
.....is that what this is all about?
Apple has this to say about that: iBooks Author: Change an object's appearance
"To return an object to its default size: Click Original Size in the Metrics inspector."
...it's an editing 'appearance' tool...not a specific file performance or output configuration setting that will make any difference when it comes to the device your book is viewed on. The file resource/size itself isn't modified during this particular process....just the appearance.
The "original size " button has been there since 1.0 and has nothing to do with authoring for the "new ipad"
and dose not change the actual image file, as KT said, just the appearence on the screen.
When you export your ibook is when it is resampled based on what size it is on the screen.
if you scale your image (which IBA does when you place an image) and want to get it to its original pix size you click that.
if you click that on a 2048 x1536 image it will be 2x the size of your document.
To author for the Retina display you need to set your pt to half what the actual image size is in pix.
ie if you place an image that is 500px x 400px you would set those to 250pt and 200pt
then it will display at the new ipads full retina resolution, on a ipad 1 and 2 it will scale it down so it is the same size on the screen.
I haven't found any documentation from Apple and, of course, no one has a new iPad to test on, but I just opened an iBooks Author project and exported to .ibooks format again without touching or tweaking anything. The old file was 20.7MB and the new file is 35MB.
Something has been added!
I originally uploaded high-res images to my iBooks Author project - 2048 on the long edge at 150dpi. These were downsampled when I first exported by iBook.
So I unzipped the new .ibooks file to see what kind of images were exported. What do you reckon I found? iBooks Author exported jpgs at 2048 on the long edge and at 144 pixels/inch.
I think Apple should really be explicit and tell authors (if they originally added high-res assets to their projects) to simply re-export the file to enable the "retina" resolutions.
Of course, I note the textures from the Jumsoft Book Palette template I used are all at 72dpi, though unsure if that makes a huge difference or is something I can easily fix without having to rearchitect the book again.
OK I've been trying to follow the various explanations here, and they all make sense untill the next response, so now I'm still confused. Bottom line, for the optimum look on all generations of iPad should I be placing my full page images into iBA at...
1024x768 (72) ?
2048 x 1536 (144) ?
Or does it make no percievable difference, because the device is doing its retina magic in the background??
Stop worrying about it. If you use 1024 x 768 (132 dpi), the image will display the same way on both versions of the iPad. If you use 2048 x 1536 (164 dpi), it will look the same as 1024 x 768 on the iPad and iPad 2, and will look marginally better on the new iPad. The difference in quality will be imperceptible to most people; you might as well stick with 1024 x 768. If you do go with the higher resolution, file size will go up by a factor of 3-4, and things will be marginally slower to load on an iPad and iPad 2 (but not so much that people would actually notice).
PS: If just done the experiment with my book on an iPad 2 and new iPad. The book with 1024 x 768 images looks identical no both devices. The only difference is with vector graphics, where thin slanted lines look better on the new iPad. Thanks to the higher resolution, there are fewer aliasing artifacts. Looking at the same image saved as 1024 x 768 and 2048 x 1536 on the two devices, the higher-resolution image looks a little better, but only marginaly so. Most people would not notice any difference. The high resolution of the new iPad comes into its own not so much for images, but for vector graphics and fonts, where there are noticeably fewer "jaggies".
New iPad / iPad 3 Retina has a screen which is physically sized as all teh others, - 1024 x 768 historically with a resolution of 72DPI / PPI.
The Retina display on iPad makes everything look crisp and lifelike. Text is razor sharp. Colours are vibrant. Photos and videos are rich with detail. All thanks to its 3.1 million pixels. It’s the best mobile display ever.
3.1 million pixels = an image size of 2048 x 1536 reversed = 3.145,728 which Apple seem to have rounded to 3.1M.
- Retina display
- 9.7-inch (diagonal) LED-backlit Multi-Touch display with IPS technology
- 2048-by-1536 resolution at 264 pixels per inch (ppi)
- Fingerprint-resistant oleophobic coating
Photographers will confirm if you have an image of 1024 x 768 @72PPI and enlarge that image - it will become progressively blurred.
While the physical size of the iPad screen remain unchanged, the resolution has, in order to give a sharper image. Increasing teh image size and resolution - gives a sharper display, and allows for finger gestures to enlarge the image on screen and remain reasonably sharp / in focus.
In the iBoostore Assett Guide No 5, Apple also give other sizes which I presume relate to images used in "written word" books as illustrations which have an on screen size of maybe 300 X 250 or whatever - so using an image of 1024 x 768 is more than adequate.
There is nothing to stop "authors" doing tests with different image sizes and checking the results on the iPad.
After many rejections with my first efforts.. I dumped everything and spent a few months going through iBA and the help files and reading this forum.
I also have a TEST.iba book which is my test bed. I can play here with all the options and gizmo's to fine tune trials to suit MY needs. Its easier to do this that mess about with content intended to be delivered to the iBookstore review team.
If in doubt - try it out!!