Troubleshooting PNG vs JPEG in EPUB

So, I wrote two articles on versioning in iBooks (here and here), but I didn't tell you my main reason for wanting to update the book.

The truth is that in the first version of my Monarch Butterfly book, my favorite page didn't work on the iPad 1. That page has 10 images, each of which measures 1600 x 1100 px. As I was exploring the possibilities of interactivity, it was one of the first pages that I created in the book. And because I had a vague (erroneous) idea that Apple preferred PNG, I decided to experiment with them.

PNG affords some advantages, including allowing transparency, at least in the 24bit version. In the later pages of the book, I used this to advantage for the arrows, so that I didn't have to position them perfectly on top of the images. In addition, PNG doesn't suffer from the licensing issues that JPEG has. On the downside, its compression is not as good, so images are larger.

Here's what the page looks like. It's set up so that if you click the images across the bottom, they are expanded into the center area, so that the reader can view and control a stop-motion movie of the caterpillar emerging from its egg, and then having its first meal. If you click the center image, the animation goes backwards.



Unfortunately, when you open the original version of this page on the iPad 1, it crashes. And like I do so often when I'm troubleshooting—and this is the real lesson of this post—I assumed that the problem was that the iPad 1 was slow and didn't have enough memory, and that I had just pushed it too far by adding too many images. I decided to upload the book as is, and warn people that it simply didn't work well on the iPad 1.

The other day, someone asked me about PNG and the NOOK and I remembered an issue I had come across a year or so ago. I was helping some folks with a book with lots of images. Not particularly big images (it was a flowing book), but lots of them. The NOOK would refuse to let you navigate to the next chapter by turning pages, even though you could choose the chapter from the TOC and it displayed just fine. Very strange. One workaround was to change the images to PNG format.

And even though the problem was the JPEG in that problem, it made me think I should try to switch from PNG to JPEG. And the crazy thing is that it worked. I'm not sure if it's because the images are smaller (233Kb instead of 950Kb), or because of the format itself, but now the page works on iPad 1 beautifully and doesn't crash.

So, the moral of the story is first, don't assume you know what the problem is, and second, let those bits of information percolate in your head and spark new theories that might help—even if they're not directly related, and third, use JPEG images in EPUB for iBooks unless you need PNG's transparency!

P.S. I've just sent an email to everyone who bought the first version of the book so that they can download the new version for free. If you don't receive the email, let me know. If you bought the book through Apple, you'll be able to update the book through the iBookstore: go to Purchased Books, and then click Update next to The Monarch Butterfly Book.

And if you haven't bought the book yet, you can find the latest version on the iBookstore or on my own website.

Versioning in iBooks (part 2)

Yesterday, after confirming that the new version of The Monarch Butterfly Book had not yet gone live, I called Apple's iBookstore support line—(877) 206-2092 in the US, see end of post for other countries' numbers—and asked what was going on. The guy was very helpful, told me that everyone had been on vacation between November 16 and November 25th, due to the Thanksgiving holiday (about which he and I both decided we were envious), but that they were back yesterday and should get to it shortly.

He also checked that I had the "What's New" material already included, which I guessed indicated that was a sticking point in many updated versions. (Remember to use the latest version of iTunes Producer to include the What's New information.)

And finally, he said he'd escalate my issue so that it would get solved as soon as possible. I almost, in the interest of science, told him not to escalate it, so that I could see and report on the real process, but sorry, dear reader, in the end, I did not.

About 12 hours later, I got the email from Apple confirming that the new version had gone live.

And this morning, I opened iBooks on my iPad and iPhone to see how those changes would be announced. What I saw was that iBooks adds a number to the Store button to indicate how many updates a reader has available, but doesn't indicate which book is affected:





When the reader presses the Store link in iBooks on the iPad, they will see Update buttons next to the corresponding books:



On iBooks on the iPhone, going to the Store will display an Updates link:



And when your reader follows the Update link, they'll see which books can be updated:



At that point, and only on the iPhone as far as I could tell, the reader can click the What's New arrow to see what has changed in the new version:



Once they click the Update button, the new version downloads to their device, and initially will be displayed with the blue "New" banner:



Once the reader has looked at the book, they won't be able to tell which version they have. I couldn't figure out any way to get information about a book's version from within iBooks on the iPad at all, or on any device once the update was downloaded. This is a serious shortfalling for what I believe is a very valuable feature.

The only way for the reader to see the versioning information of an existing book, including what has changed from version to version, is to go to the iBookstore, look up the book, scroll down to the bottom of the Book Description or Details area, and check the What's New section.



The reader can also get a full rundown on the differences from one version to the next by clicking Version History. I think it's rather confusing to use a header like "Version 3.0" when what they mean is that the changes listed are for the EPUB3 version of the book. It is only below that you see the version number that I gave the book: 1.1.

Therefore, you might want to add version info to one of the pages of your book (the copyright page perhaps?) if you want readers to be able to tell which version they have. (I'll do this next time.)



So, still some wrinkles to be ironed out, but I continue to think that versioning is a brilliant idea. Now I have to update some of my other books so I can see what happens with notes and bookmarks (which aren't allowed in a Fixed Layout book like this one.

There were two major errors that were fixed in this version of The Monarch Butterfly book: some arrows that were in the wrong place on page 24, and something much more important, which I'll discuss in my next post, about JPEGs and PNGs.

You can buy The Monarch Butterfly Book on the iBookstore (and thus be notified as described above about new versions), or directly from me (via Kagi) (in which case I'll notify you personally about new versions to this book as well as any new books via email).

---

Here are the iBookstore support telephone numbers:

Australia: 1300 307 504 (Note that this is a low tariff number.)
France: 0805 540 117
Germany: 0800 664 5307
Italy: 800 915 902
Netherlands: 0800 0201 578
Spain: 900 812 687
U.K.: 0800 975 0615
U.S.: +1 (877) 206-2092
Toll-free from U.S. and Canada.