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Examine Image

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Buffer Selection Box

Examine Image allows you to view your images and to measure various quantities. It is also used in Aligning Images, Calibrate and Measure, etc. Upon selecting Examine Image, you will be asked to choose a buffer to view. You may click on any of the buttons, use the Arrow keys to move to a button followed by {Enter}, or press one of the A, B, or C keys (upper or lower case). If there is no image loaded into the buffer you select, you will get an error message and the operation will abort.

Once the image is displayed, there is printed information across the top. The name of the image file is displayed along with the row and column location of the cursor, the box size, the average of the pixel values within the cursor box, the RMS noise of the pixel values within the box and the magnitude of the values within the box. Depending on whether or not the image has been calibrated, the RA and DEC location of the cursor may or may not be displayed.

The power of Examine Image is contained in its hot key functions. The following list describes them.

Hot Key     Function/Effect

-------     ----------------
Arrow Keys  Moves cursor 1 pixel in direction indicated.


{Home}      Moves cursor up 5 pixels.      | Note: These keys
{End}       Moves cursor down 5 pixels.    | form a 'diamond' on
{Delete}    Moves cursor left 5 pixels.    | the standard 101
{PageDn}    Moves cursor right 5 pixels.   | keyboard.


{Ctrl} {->}     Increments Box Size
{Ctrl} {<-}     Decrements Box Size


8, I, i     Moves cursor up 20 pixels.     | Note: These keys
2, M, m     Moves cursor down 20 pixels.   | form a 'diamond' on
4, J, j     Moves cursor left 20 pixels.   | the standard 101
6, K, k     Moves cursor right 20 pixels.  | keyboard.


A, a      Displays Buffer A (if data present)

B, b      Displays Buffer B (if data present)

C, c      Displays Buffer C (if data present)


{Alt} C   Accesses the Copy Function


{Alt} F     Flips image Right to Left

{Alt} I     Inverts image Up to Down


H, h      Accesses the Histogram Function


N, n      Exits leaving Mouse Tracks


P, p      Finds the center of brightness of the box (if threshold has been set)


{Alt} P   Accesses the FITS Parameters Function


Q, q      Exits to Main Menu


R, r      Rescales BLACK and WHITE levels


S, s      Sets SawTooth level.


T, t      Sets average value in box as background threshold


V, v      In VGA 320x200 video mode only, flips to data screen


X, x      Shows cross section of data in box.



{ESC}     Exits without Mouse tracks

Pressing any other key will produce a 'boo boo' beep and no other action.

Most actions involving the Scale, Filter, Merge, or Transform menus will operate on the image in the A buffer and display the result in the B buffer using the Examine Image mode. By flipping between the two buffers using the A and B keys you can appreciate the effects of the operation.