Automatic digitizing options

Here you can adjust settings that apply for automatic digitizing of lines and symbols. Open the dialog with Auto->Options.

1) Max. RGB color difference
Every color in the graph can be expressed by three bytes, one for every color component (red, green, blue). Values range from 0 - 255. DigitizeIt decides if a certain pixel of the graph belongs to a line or a symbol based on the comparison of colors. Every color component is compared separately, the difference may not exceed the max. RGB color difference, that you can choose here.
The pixel you clicked onto, in order to start the digitizing process, sets the reference color.

So, a value of 0 means colors must match exactly, 255 means every color matches (not useful!).

This setting applies to both line and symbol digitizing.

2) Symbol matching in %
This value determines how well a symbol must match the symbol, that you want to digitize, to be considered the same. It sets the number of pixels, that can be different in % of the number of total pixels of the symbol. (If two pixels are the same is determined by the max. RGB difference setting.)

A value of 0 requires symbols to match exactly, 50 means 50 % of the pixel symbols may be different.

If the symbol detector does not find all of your symbols choose a higher value here, if it finds too many symbols choose a lower value.

3) Max. number of digitized points on line
Lines are digitized with one data value per graph pixel in x-direction by default. If the number of data points exceeds the value given here, data values are interpolated to produce a data set with the number of equally spaced data points given here.