Creating an Alphabet ebook in Bloom


We’re trying to optimize our alphabet book for Bloom Reader.
Here are the specs:

  • 49 page book
  • 3 images per page
  • 4 Mp3 files for audio

We reasoned that instead of 3 separate images, merging them into one might help speed up the book.
?? Would it?
Now we’re thinking of merging the three textboxes as well, and merging the audio.
?? Could that have a positive effect?

Thanks a lot,

Hi Koen,
I don’t think we’re even aware of speed problems, so we don’t know what the cause is or what the solutions might be.

Another question to add to yours: does the number of pages matter?

Let us know what you find.

If this book is ever translated, it’s unlikely that the same sets of images will end up on the same pages (for example, the translations of fish, fire, and fly probably don’t all start with f any more). Such a re-arrangement of the book would be difficult currently, but we’re working on it! However, merging the images would make it much harder.
Also, if anyone wants to reuse these images in other books, merging will make that harder too.
It would also, of course, complicate things if any of the images that need to be merged don’t have the same copyright and license information.
So, I would only consider doing it if it produces a large improvement in speed that you think is really needed.

Hi there,
I need to admit that I know very little about Bloom, but with digital images in general, merging 3 into 1 will not affect the total size of the image, so theoretically it should take the same amount of time to load (assuming the file load overhead is negligible). As others have said, merging into 1 might create problems for localization since the 3 pics will not likely be together elsewhere.
For images, however, it IS important how compressed they are. The source images should be resized down to your output device width (in this case, a phone screen). Since there are many phone screen resolutions (likely different for each model), you’ll have to take a stab at a happy medium e.g. 768 pixels wide divided by 3 for the width of each image. Use IrfanView or equivalent to size the image down and save as a PNG or JPG (whatever Bloom requires). Look at the resulting size in KB and see if you’ve saved some space. Run a few tests on different phones to see if the images are clear.

Bloom down-samples all images to a max of 600 x 600 when going to BloomPUB format. If a different approach is needed, we would be happy to discuss that.