Is it feasible to divide any layer in Pixelmator and then merge them again? I would like to convert this image (640 x 1136) to 640 x 960, but have to convert it without touching on the navigation and tab bar on the top and bottom of the screen. So I came up with an idea of first dividing the screen, and on one of the divided layer, cut 640 x 196 image, and then merge them again in order to archive 640 x 960 by only tinkering the white part.
However, it looks like it's impossible to divide the layer in Pixelmator - actually, the slice
tool is only for the use of Web. So how can I get 640 x 960 image?