I just did a test. I sized an image in Photoshop to 1024 x 768 x 150 ppi, saved as a JPEG file. I created an iPad size page using the Digital Publishing Suite intent, and placed the image at full size (no bleed).
I exported using File > Export > Adobe PDF (Interactive).
I transferred to my iPad with Dropbox, and opened in iBooks and in PDF Reader. Looked exactly the same in each: full bleed with no margins. I made a screen shot (clicked Home and Sleep/Wake button) and emailed it back to my Mac.
Looks exactly the same as the image above. No margins.
Make sure you size your pictures correctly before placing in InDesign.