Modifying an Image
From Apache OpenOffice Wiki
Modifying an Image
When you insert a new image, you may need to modify it to suit the document. The placement of the picture relative to the text is discussed in “Positioning Graphics within the Text”. This section describes the use of the Picture toolbar, resizing, cropping, and a workaround to rotate a picture.
Writer provides many tools for working with images. These tools are sufficient for most people’s everyday requirements. However, for professional results it is generally better to use an image manipulation program such as GIMP to modify images (for example, to crop, resize, rotate, and change color values) and then insert the result into Writer.