Background picture

It is used for visualization or for digitization of points.

Image

Visible Select to display or not the background picture.
<Open> Drag and Drop file (bmp, gif, jpg, wmf, emf) or click button.
<Paste>  An image stored on the Windows Clipboard as bitmap will be pasted into your outline. 
<Save As>  Saves your background picture file to disk. All filters you selected will be applied. 
<Copy>  The background picture will be placed on the Windows Clipboard as bitmap image, and may be pasted in elsewhere. 
<Default>  Restores parameters (filters, placement) used by default. 

Filters

Black and White The image is converted to black and white.
Negative The image is converted to a reversed color version of the original.
To Grayscale The image is converted to grayscale.
Sharpen Apply the sharpen filter.
Edge Detection Finds the main lines in an image and replaces their color with the opposite color, at the same time most fill colors are darkened, making them like a background.
Median Filter Causes a group of pixels to have the brightness of the average pixel in that group.
Threshold Move the setting up, to exclude pixels with high brightness.
Neighbors Move the setting up, to exclude single pixels.

Placement

Resize to plot Select to resize or not the background picture on whole size of plot.
On page center Select to draw the background picture on page center or on left upper corner.
Vertical Flip The image will turn upside-down.
Horizontal Flip The image will turn side-to-side, as in a mirror.
Rotate 90 The image will turn 90 degrees.
Rotate This allows you to enter an angle (in tenths of degrees, range: -900 - +900) for the image rotation,

Trick: Use <Add Points from Screen><Capture Area> tool to get the background picture.