Image problem when reading epubfiles on android tablet.

[AC Question]

I have some validated epub-files with text and images. It is no problem to read them i Adobe Digital Edition in the computor or in Bluefire Reader in an iPad, but in my android tablet (Samsung Galaxy Tab S2) the images are too small to be readable. I have tried in the apps Bluefire Reader and Aldiko and it is the same problem in both of them. It doesn´t help to set the image width to 100%.