Bitmap Overlay

This is the overlays window shown for a bitmap overlay. Many of the buttons in the bitmap overlay window are the same as for the experimental overlay window, as described here.  However, unlike an experimental spectrum, a bitmap spectrum does not contain frequency and intensity points.  It is therefore necessary to set the frequency scale manually by identifying two points on the spectrum with known frequency:
  1. For the first point, click the Xpixel 1 button, and then click on the point in the bitmap spectrum. Enter the corresponding frequency at Frequency1 in the grid.
  2. For the second point, click the X pixel 2 button, and then click on the point in the bitmap spectrum. Enter the corresponding frequency at Frequency2 in the grid.
If you want to set the vertical scale:
  1. Click the baseline button and then click on a point on the baseline in the spectrum.
  2. Click the maximum button, and then click on a point on the highest point of the spectrum.
  3. If you need to change the vertical range produced (the default is 0 to 1) change the BaselineIntensity and MaximumIntensity values in the grid.



Moving the cursor to a point on the bitmap gives an x and y pixel number in the status bar and, when the wavelength and intensity scale have been set, shows the wavelength and intensity of that point. 


This is where the start and end frequencies, baseline and maximum intensities are set manually.  A frequency offset can also be applied, if necessary.


This is where the points for the start and end frequencies, and the points for the baseline and maximum intensity will be entered (the numbers are entered automatically on pressing the , , and buttons and clicking the appropriate point on the bitmap).



This shows and allows you to edit a comment on current item. The comment is not used elsewhere and there is no limit on the comment length.

Toggle display between fit to window and actual size.
Compact bitmap by reducing to a single colour.
Cancel setting variables by mouse.
Set point for Frequency 1 with the mouse. 
Set point for Frequency 2 with the mouse.
Set baseline point with the mouse.
Set Maximum intensity point with the mouse.
Delete peaks from this overlay.
Discard bitmap outside selected area.
Undo work done with "Crop" button.
Convert photographic plate spectrum to a conventional overlay, as shown in the example below.