In GIMP, a layer is not always the same size
as the image it belongs to. It might be smaller or it might be larger,
in which case some parts of it are hidden. The
Layer Boundary Size command displays a dialog
in which you can set the dimensions for the active layer. This command
changes the dimensions of the layer, but it does not scale its contents.
Activating the Command
You can access this command from the image menubar through
Layer->Layer Boundary Size.
Description of the “Layer Boundary Size” dialog
The “Layer Boundary Size” Dialog
When the dialog is displayed, the original dimensions of
the active layer are shown. You can change them by using
the two text boxes. If these boxes are linked together
with a chain, the width-to-height ratio is automatically
maintained. If you break the chain by clicking on it, you
can set the dimensions independently of each other.
The default unit of measurement is pixels. You can change
this by using the drop-down menu. For instance, you might
use a “%” of the current size.
X Offset; Y Offset
By default, the resized layer is placed in the upper left
corner of the image. Here, you can set the offset of the
upper left corner of the layer relative to the same corner
of the image. The default unit of measurement is pixels,
but you can change it by using the drop-down menu. You can
also place the layer in the center of the image by
clicking on the Center button.