diff options
Diffstat (limited to 'pkg/images/tv/iis/doc/window.hlp')
| -rw-r--r-- | pkg/images/tv/iis/doc/window.hlp | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/pkg/images/tv/iis/doc/window.hlp b/pkg/images/tv/iis/doc/window.hlp new file mode 100644 index 00000000..f98130c3 --- /dev/null +++ b/pkg/images/tv/iis/doc/window.hlp @@ -0,0 +1,38 @@ +.help window Jan86 images.tv.iis +.ih +NAME +window -- adjust the contrast and dc offset of the current frame +.ih +USAGE +window +.ih +DESCRIPTION +The lookup table between the display frame values and the values sent +to the display monitor is adjusted interactively to enhance the display. +The mapping is linear with two adjustable parameters; the intercept +and the slope. The two values are set with the image display cursor +in the two dimensional plane of the display. The horizontal position +of the cursor sets the intercept or zero point of the transformation. +Moving the cursor to the left lowers the zero point while moving the cursor to +the right increases the zero point. The vertical position of the cursor +sets the slope of the transformation. The middle of the display is zero +slope (all frame values map into the same output value) while points above +the middle have negative slope and points below the middle have positive +slope. Positions near the middle have low contrast while positions near +the top and bottom have very high contrast. By changing the slope from +positive to negative the image may be displayed as positive or negative. + +The interactive loop is exited by pressing any button on the cursor control. +.ih +EXAMPLES +.nf + cl> window + Window the display and push any button to exit: +.fi +.ih +BUGS +It may be necessary to execute FRAME before windowing. +.ih +SEE ALSO +cv +.endhelp |