Size Use the Width and Height fields to set the size of the overlay image in pixels.
The image size can also be changed by dragging the image's scale handles on the canvas viewer when the image layer is selected.
By checking the "Keep Aspect Ratio" checkbox, the width to height ratio of the image will be maintained when changing the scale using the properties panel or scale handles on the canvas.
Rotation The image can be rotated using the canvas widget's rotate handle, or by specifing a value in the Rotation: field.
Flipping The image can be flipped (or mirrored) using the Flip Horizontal and Flip Vertical buttons.
Opacity Use the Opacity: slider to adjust the transparency of the overlay image.
Sharpness When a selection is deleted from the overlay image, the Sharpness slider can be used to blur the edges of the overlay image.