Apply Column Bias


The Apply Column Bias method is used by the Calibrate Images command to apply an underscan or overscan bias correction to images. This method corrects for the bias value evaluated at the time the image was readout from the CCD. The bias is computed as a column vector using fictitious columns at the beginning or end of the rows.

Applying a Column Bias correction requires the following information to be specified on this page of the Calibration dialog:

Column Bias Methods

Mira offers a number of alternative methods for creating the column bias vector from the sample region. These options range from directly subtracting every column to fitting the mean row with a n-th order polynomial. Each of these options involves specifying a pixel region where the bias is obtained (see the next section, below).

Specifying the Bias Region

The bias region defines the pixels that are used to determine the bias correction function or value. Mira offers 2 ways to specify the pixels used for determining the bias:

Related Topics

Apply Row Bias, Create Bias Frame, Apply Bias Frame, Image Calibration, Methods tab