; TVHLD ;--------------------------------------------------------------- ;! Task to load a map with histogram equalization ;# TASK TV ;----------------------------------------------------------------------- ;; Copyright (C) 1995, 1999, 2009 ;; Associated Universities, Inc. Washington DC, USA. ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;----------------------------------------------------------------------- TVHLD LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC TVHLD: Task to load a map with histogram equalization INNAME Image name(name). blank=>any INCLASS Image name(class). blank=>any INSEQ 0.0 9999.0 Image name(seq. #). 0=>any INDISK 0.0 9.0 Disk drive #. 0=>any TBLC 0.0 4096.0 Bottom Left Corner of image 0 => entire image TTRC 0.0 4096.0 Top Right Corner of image 0 => entire image TXINC 0.0 256.0 Load every TXINC'th column TYINC 0.0 256.0 Load every TYINC'th row TVCORN 0.0 512.0 TV pixel location of bottom left corner of image PIXRANGE Min,Max of image intensity 0 => entire range FUNCTYPE Transfer function for LOADING 'LN' Linear 'LG' Logarithmic 'SQ' Square root 'NE' Negative linear 'NG' Negative logarithmic 'NQ' Negative square root else: Linear SCALR1 0.0 13.0 Number of bits to use while loading; 10=>13; anything else defaults to 13 ---------------------------------------------------------------- TVHLD Type: Task Use: TVHLD loads a map image into the TV in up to 13 bits and, based on histogram equalization, then calculates an input transfer function to compress it to 8 bits. This maxi- mizes the dynamic range visible on the TV. The back ground may be removed, i.e., all pixels below a certain pixel value are made invisible; the rejection level is controlled by the cursor. The peak of the intensity histogram is given at the beginning. Button A switches between a quasi-linear equalization function and a log- arithmic one; the "linear" function favors the lower intensities, the "logarithmic" the higher ones. Button B switches between spectrum colors and gray scale. Button C causes the present image to be put into TV channel 1 and the program to exit. Button D just causes an exit, leaving the image in TV channel 3. The cursor's Y position controls coarse tuning of the back ground rejection level, its X position fine tuning. At the top of the screen are shown: the equalization function (lin or log), the position of the peak in the histogram, and the current back ground rejection level. The number of bits used in loading the image is controlled by SCALR1; it can range from 10 (1024) to 13 (8192) - any- thing else defaults to 13. Obviously, the higher the num- ber of bits, the higher the dynamic range that can be dis- played; however, it also increases the sluggishness in the response to the cursor. ----------------------------------------------------------------