Calibration Tool Panel

The Calibration Tool Panel displays the calibration data, fitting function and coefficients. The panel can be accessed under “Panel” in “Menu” or “Film calibration” in “Case Data Selector.” It allows you to create calibration file based on the user-defined section of the calibration images.

A. The “Calibration Function” chart displays a calibration plot of “color value vs. absorbed dose” for each color channel. There must be enough data points in the “Calibration Table,” C, to fit to a selected calibration function and display the plot.

• To zoom in, left click and drag from top left to bottom right to outline the selected region. To unzoom, right click and drag from bottom right to top left.

• Right click inside the chart to change the unit of x- and y-axis or copy the chart.
  • Select “Number of function values” to change the number of points interpolated by the fitting function selected.
  • Check or uncheck “Show discrete calibration values” to show or hide the data points from the “Calibration Table,” C
  • Select “Options” to change the configuration of the chart.
    

1. The “Data Range Minimization” button allows you to reduce the range of the axes in the calibration chart to the discrete range of the calibration data, i.e. minimum validity range of the calibration.
2. The “Data Range Maximization” button allows you to extend the range of the axes in the calibration chart to the full color interval and corresponding dose range, i.e. the maximum utilization range of the calibration.
3. The “Calibration Color Channel” icon allows you to change the color channels displayed in the calibration chart. The selection does not affect the calibration. It only changes how calibration functions are displayed.

B. The “Calibration Model Equation” drop-down list allows you to choose the equation used to correlate the calibration data.

• All model equations are invertible over the fitting range, i.e. both functions “Color channel vs. Dose” and “Dose vs. Color channel” are available.
• All model equations are differentiable, i.e., changes in dose are continuous and smooth.
• The color channels red, green, and blue are fitted separately.
• The drop-down list displays the name with the equation chosen:
  • X is the color channel value between 0 and 1.
  • D is the absorbed dose.
  • A, B, and C are the parameters used to correlate dose and color channel value.

4.The “Equation Parameters” icon allows you to select whether calibration function parameters of the color channels are shown. The icon appears as when parameters are hidden.

 

C. The “Calibration Table” allows you to view and enter the data points associated with the calibration patches.

• The first column indicates the exposure dose of the imported film. During the calibration process, the dose values for the exposed calibration patches are entered in this column to generate a “Calibration Function” chart, A See details in “Calibration.”
  • Right click inside the column and select “Scale ‘Radiation absorbed dose’ column dialog” to enter two value pairs to generate a conversion equation to scale the calibration dose column.
    
    
• The other columns contain the average color-values for the regions of interest of the calibration patches for different color channels. Right click inside the columns to copy, paste the table or column, insert or delete rows, change the unit, or change the configuration of the table.

5. The “Number Format Buttons” feature allows you to change the format of the number displayed in the table.

6. The “Synchronize” button allows you to synchronize color channel values with radiation absorbed dose values. It reassigns calibration table so that the radiation absorbed dose values and selected channel values are sorted ascendingly. Click on the button to select the color channel preferred to synchronize. Synchronization works only when “Auto Copy,” 7, is on

7. The “Auto Copy” button allows you to copy color channel values from the image selection in “Image Panel.” The color values across each selection frame is averaged and copied to the calibration table. The icon appears as when the auto copy feature is on.