Grab and Display Menu

Grab and Display Menu

The grab and display menu contains all the basic frame acquisition and display routines required by DigImage. If an offboard buffer is to be grabbed, displayed or otherwise manipulated, it is first acquired to or copied to buffer 0. Buffer 0 is designated to this task and should not generally be used for other purposes.

NOTE: There are additional acquisition routines in the VHS menu (option V from the main menu) suitable for automatic frame grabbing, especially when large intervals are required between the frames.

A Acquire a sequence of frames, performing operations on them with the ALU during the acquisition. The operations supported include averaging, subtraction, logical operations etc.

F Freeze frame.

This will stop any continuous acquire operation which may be in progress.

G Grab a single frame.

The synchroisation is by the user pressing a key. The current zoom factor may be either maintained or reset during the acquisition process. If reset, it will be restored when the acquisition is complete.

T Grab a single frame after a delay.

Waits for a specified length of time before acquiring a single image.

S Grab a sequence of frames (at specified times).

These frames may be saved to disc automatically if an optional base file name is supplied.

X Grab and display frames at a specified frequency to simulate a strobe effect.

Y: Set the multiplexer input channel.

Eight are available if the DT2859 board is fitted. If the board is not fitted, this option has no effect.

R Real colour grab.

This option is useful only if the DT2859 board is fitted and a PAL, NTSC or Y/C to RGB decoder connected with Red to input 1, Green to input 2 and Blue to input 3. Input 0 will normally be monochrome. The full colour image is acquired by seqentially acquiring the three colour components. Bits 0, 3 & 6 contain the Red, bits 1, 4 & 7 the Green and bits 2 & 5 the Blue.

B Display a specific buffer.

D Display a sequence of buffers.

The sequence may contain up to 32 buffers (each buffer may be displayed more than once in the sequence). The sequence speed is specified in seconds and the sequence is repeated until Q is pressed. The up and down cursor keys may be used to increase or decrease the speed of the sequence. <pageup> and <pagedown> have a similar effect with larger steps. <home> and <end> takes the speed to the two extremes (ie. as quickly as possible and 10s between each frame, respectively) while D allows a specific value of the delay to be given.

<down> Display the next logical buffer. This option is equivalent to pressing function key f1.

D Display sequence of buffers.

Display a sequence of images in succession on the monitor.

<up> Display the previous logical buffer. This option is equivalent to pressing function key f2.

J Display summary of buffers - automatic.

This option creates a mosaic of the contents of 4, 9, 16, 25 or 36 buffers using buffer 0. The buffers are displayed in order starting with a user-specified buffer number. Refer to [L Display summary of buffers - specific] for summarising buffers in a different order.

K Display buffer on computer monitor.

This option displays a single buffer on the computer monitor, allowing simultaneous viewing of more than one image.

L Display summary of buffers - specific.

This option creates a mosaic of the contents of 4, 9, 16, 25 or 36 buffers using buffer 0. The buffers are displayed in user-specified order. Refer to [J Display summary of buffers - automatic] for summarising buffers in numerical order.

M: Manipulate image.

This option provides access to the image manipulation submenu. Contained in this submenu are a variety of logical, arithmetic and bit-wise operations using either two buffers, or a single buffer and a constant.

Z Zoom and pan.

Note that this facility also allows the display of a cursor and the location/intensity at the cursor. If cursor display is not wanted, then this may be disabled by option O (turned on again by a second O). When exiting, Q will reset the current zoom, while P will maintain the present zoom.

C Copy a buffer.

Copy one buffer to another.

E Erase a buffer.

Erase the contents of a buffer.

N Exchange buffers.

This option interchanges the contents of a pair of buffers.

I Display an intensity scale.

Display scale on the current buffer at one of four possible locations.

O: Output look up table.

Enter the output look up table submenu.


Parent menu

Main Menu

DigImage User Documentation


Stuart Dalziel, last page update: 19 February 1996