Opens a dialog for editing the zoom factor. This value is given in percent and always refers to the initial size of the picture.
Enlarges the image by ten percent. Notice that this refers to the current size of the picture.
Reduces the image size by ten percent. Again this refers to the current size of the image.
Doubles the current image size.
Cuts the image size by half. As above, this refers to the current image size.
Maximizes the image size. The image is scaled to the window size. This action does not preserve the aspect ratio.
Maximizes the image size. Again, the image is size is maximized, but this time keeping the aspect ratio constant.