Recently i wanted to change my android lockscreen for my SGS2, and had some trouble doing so.
There are different apps on the android market for this but i do not want to install an app for it because i have apps enough allready.
Here i will describe a way to set you lock screen so your selected image is allways full screen, without the need for any extra application. Its very simple, but i didn't find it anywhere on the internets to do it this way so i thought i'd write it up real quick.
Because android allways shows the cropping option for the selected image, even though the image resolution is the same as your screen resolution, leaving you with a background showing only half the image, with no way to zoom or expand the canvas.
Its very simple really. For my SGS2, my screen resolution is 480x800. So to workaround the bug, just create a new image in any image editing program of your choise with DOUBLE the width resolution, for the SGS2 that would be 960x800. Paste your image in the middle and save.
It should look something like this:
Then re-upload it to your phone, and set it again as lockscreen, the image should now appear in the selected box 100%, and the rest is cropped.
FYI: if you cant find how to set a lockscreen, just open the image gallery, browse to the picture you want to set. Then in options -> Set As... -> Lock Screen
