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QDI(PARM)/DIP(ARM) - Enquire and alter display parameters

The Lexidata display has 10-bit planes, and can therefore display numbers in the range 0 to 1023. Since the CCD produces 16-bit numbers, a choice has to be made about how to handle the 6 high bits. Three options are provided which give a trade-off between speed of diplay and the appearance of the image. To find out what the current option is, use QDIPARM. To change the display parameters, use DIPARM.

Parameters

QDIPARM requires none. DIPARM has three, which will be prompted for if not given. The first parameter determines which of the three options is selected. The second and third parameters are the data values to map to the minimum and maximum of the Lexidata intensity scale. The options are:

1. This is the default option. The highest 6 bits of each data pixel are simply ignored when passed to the Lexidata. This option is therefore the fastest since no data manipulation is performed. The second and third parameters are not needed and will be ignored if given.

   Example

   Adam:> DIPARM 1

2. This option is called FOLD. This will scale the data and then wrap round.

   Example

   Adam:> DIPARM 2 0 2047

   In this example, a data value of 0 will be mapped to the minimum of the Lexidata intensity scale and 2047 will be mapped to the maximum. As FOLD is selected, all data values which differ by a multiple of 2048 will be mapped to the same Lexidata intensity; e.g. data values 0, 2048, 4096 etc. will all be mapped to the minimum intensity.

   This is the second most efficient way of displaying the data and retains the maximum information content.

3. This option is called TRUNCATE.

   Example

   Adam:> DIPARM 3 1000 4000

   In this example, data values below 1000 will all be mapped to the minimum of the Lexidata display scale, and values above 4000 will all be mapped to the maximum.