Have been trying to send feedback to Adobe for ADE but apparently Adobe isn't interested: ADE isn't included in the list of software in the feedback form. Am hoping that perhaps someone is listening in here.
Here's my beef: I am a firm supporter of DRM, but Adobe's ADE is so bad of an ereader that it defeats its own purpose.
My book uses multiple images, most of which are screen shots of instructions and so legibility is critical. Many images have a height of 800 pixels and are thus too tall to fit on a typical 15.4" laptop screen, smaller tablet or mobile phone; and images set to 600 pixels wide are too wide for small devices. So in order for the images to be scaled, I cannot set a fixed pixel size; I have to use "height=100%" or "width=100%" value. Unfortunately, ADE interpolates the images so badly that they look like crap. I would expect ADE's image handling to be on par with at least Amazon's Kindle apps, but no; Kindle apps mop the floor with ADE.
If I then use a fixed pixel size so that the images are not interpolated, tall images are cut off the laptop screen at about 650 pixels while wide images are cut off at the sides on smaller devices. And unfortunately, ADE doesn't allow the user to scroll down between pages, or from side to side; it only jumps from page to page.
It's the same with the Nook, Sony,and Kobo for PC apps that can read ADE DRMed books: on my 15.4" laptop, the Sony reader app cuts off images taller than 525 pixels, and Kobo and Nook apps cut images off at about 500 pixels high.
Users can install popular free programs such as Calibre, which has an ereader that scrolls down as well as jumps from page to page. Unfortunately, Calibre cannot open DRMed ebooks. Ditto for Sigil.
So now the tablet, PC, or mobile user has to find an ereader app that will both open ADE files AND either does a better job of image handling or has a scroll function for viewing tall fixed-pixel images. By this time the user -- who has most likely purchased the book through Kobo, Nook, or Sony and is trying to read it on their app -- has said "screw this" AND is cursing the book publisher and vowing never to buy a DRMed book again. Or has gone instead to find an app to remove the DRM, again defeating the purpose.
Since the majority of tablets and all laptops have a screen width equal to or greater than 600 pixels, one can safely use a fixed image size for anything 600 pixels or less in width and not suffer the horrible uprezzing that occurs if one uses a "width=100%" value; and just leave mobile phone users to suffer.
But with tall images, it's not so simple. If ADE would just allow downward scrolling, the problem would be solved: one could safely use a fixed pixel value and let the laptop user scroll down through the image.
So why has Adobe missed such an obvious feature? And until ADE does a better job of image handling, its ereader will continue to be subpar. It's not good enough to assume most people have a dedicated ereading device; many are using tablets and it's as if Adobe is pretending these consumers do not exist.