Provided by: radiance_4R1+20120125-1.1_amd64 bug

NAME

       ximage - RADIANCE picture display for X window system

SYNOPSIS

       ximage  [ =geometry ][ -di display ][ -c ncolors ][ -d ][ -b ][ -m ][ -g gamma ][ -f ][ -e
       spec ][ -ospec ][ -t intvl ][ -s ] picture ..

DESCRIPTION

       Ximage takes one or more RADIANCE picture files and displays them on an X server.  The  -c
       option  specifies  the number of colors to use (default fills color table).  The -d option
       turns off color  dithering.   The  -b  option  displays  the  image  in  black  and  white
       (greyscale).   The  -m  option  forces  monochrome  output.   The  -g option specifies the
       exponent used in gamma correction; the default value is  2.2.   The  -f  option  stores  a
       Pixmap on the server side for faster refresh.  This may not work with large images on some
       servers.  The -o option specifies a sequence of  information  to  print  to  the  standard
       output  for  the  't' command (see below).  The -t option specifies a minimum interval (in
       milliseconds) between  successive  ray  outputs  in  mouse  tracking  mode  (right  button
       pressed).

       The -e option specifies an exposure compensation in f-stops (powers of two).  Only integer
       stops are allowed, for efficiency.  If the special word, auto is given instead of a number
       of  stops,  then  ximage  performs  an  automatic exposure adjustment similar to pcond(1),
       compressing the dynamic range of the image to fit within the dynamic range of the display.
       If  the  special word, human is given instead, then ximage performs an exposure adjustment
       similar to pcond with the -s and -c options, which compensate for human contrast and color
       sensitivity  at  the  corresponding  scene  luminance  levels.   This  option  yields  and
       appearance of the scene on the display that closely matches what would be  experienced  in
       the real world.

       The  -s  option tells ximage to display multiple pictures sequentially, rather than all at
       once.  If no picture is given, input is read from stdin  provided  either  the  -b  or  -m
       option  is  in  effect,  or the X server is capable of 24-bit color.  However, many of the
       commands given below will not work.

COMMANDS

       Once a picture is displayed, the user may perform a number of  operations.   Some  of  the
       operations  make use of an area of interest, defined by pressing the left mouse button and
       dragging the cursor over a section of the image.   Pressing  the  button  and  immediately
       releasing  it  defines  a  single  point  as  the area of interest.  A command is a single
       character.

       q         Quit picture.  (Also Q or ^D.)

       <space>   Redraw the area of interest.

       ^R        Redraw the entire image.

       <return>  Display the radiance averaged over the area of interest.   The  maximum  of  the
                 three (RGB) channels is reported.

       l         Display  the  photometrically-weighted  luminance value in the area of interest.
                 This assumes that the image was correctly computed in terms of luminance.

       c         Display the color in the area of interest, as adjusted by the  current  exposure
                 setting.

       p         Display the x and y location of the cursor.

       i         Identify  identical  pixels  by assigning a random color at the cursor position.
                 This is useful for displaying contours, especially when  combined  with  the  -b
                 option.

       t         Print  information  about  the  pixel  under  the cursor according to the string
                 following the -o command line option.  The  valid  characters  for  this  option
                 correspond roughly to the other ximage commands:

                 o    ray origin

                 d    ray direction

                 v    radiance value

                 l    luminance value

                 p    pixel position

                 The  default  output is "-ood", which prints the ray origin and direction.  This
                 can be used as input to rtrace(1) to get additional information about the  image
                 (ie.  pipe  the output of ximage into rtrace).  Pressing the middle mouse button
                 is equivalent to typing the 't' key.   Pressing  and  holding  the  right  mouse
                 button is equivalent to continuously pressing the 't' key.

       =         Adjust  the  exposure  to  the  area  of  interest.   A crude adjustment is made
                 immediately, and the number of stops is printed while the colors are  resampled.
                 After a few seconds to a minute, the final image is redisplayed.  If the area of
                 interest is already within 1/2 stop of the ideal, no adjustment is made.

       @         Same as '=' command, only the exposure is adjusted to provide roughly  the  same
                 visibility for the selected region on screen as a viewer would experience in the
                 actual space.  Like the 'l' command, this adjustment assumes that the image  has
                 been  correctly  computed  in  terms  of  luminance.  (See also the 'h' command,
                 below.)

       a         Perform automatic exposure compensation, as if ximage were started with  the  -e
                 auto option.  If a rectangular area has been selected, the pixels in this region
                 will be emphasized in the histogram, offering  this  area  exposure  preference.
                 (Each pixel within the rectangle will be weighted as 21 outside pixels.)

       h         Perform human expsoure compensation, as if ximage were started with the -e human
                 option.  See the 'a' command above regarding pixel weighting.

       0         Reset the origin to the upper left corner of the image.  This command is used to
                 restore  the  original  image position after using the shift or control key with
                 the mouse to relocate the image within the frame (see below).

       f         Switch on the fast redraw option (-f), loading the  image  pixmap  over  to  the
                 server  side.  This command is useful when network delays are causing slow image
                 refresh, and the user didn't notice it until after ximage was started.

       F         Switch off the fast redraw option.  This frees up some memory on the server,  as
                 well as the color table for other windows.

       In  addition  to the commands listed above, the control or shift key may be held while the
       cursor is dragged to reposition the image within the window.

X RESOURCES

       radiance.gamma the default gamma correction value

ENVIRONMENT

       DISPLAY_GAMMA       the default gamma correction value

AUTHORS

       Greg Ward
       Anat Grynberg (Paris)
       Philip Thompson (MIT)

SEE ALSO

       aedimage(1), normtiff(1), pcond(1), pfilt(1), rpict(1), rtrace(1),  rvu(1),  xglaresrc(1),
       xshowtrace(1)