XTIFF(1)                X Version 11(December 20, 1990)                XTIFF(1)


NAME
      xtiff - view a TIFF file in an X window

SYNOPSIS
      xtiff [ standard Xt options ] [ -gamma gamma ] [ -usePixmap (False |
      True) ] [ -viewportWidth pixels ] [ -viewportHeight pixels ] [ -translate
      pixels ] [ -verbose (False | True) ] file

DESCRIPTION
      xtiff is a TIFF viewer for X based on the libtiff(3) package.  It
      displays a TIFF file in an X window that can be resized and panned.  On
      appropriate display hardware it can handle 24-bit RGB color TIFF files,
      8, 4 and 2-bit palette color TIFF files and 8, 4, 2 and 1-bit grayscale
      TIFF files.  The Next and Previous buttons allow the user to view
      different pages in a multi-page TIFF file.

      If the image is larger than the window, you can pan around the image with
      the mouse or arrow keys.  Grab the image by pressing down and holding the
      left mouse button and then drag the mouse to expose a different region of
      the image.  The arrow keys provide another method for moving a large
      image inside a smaller window.

      xtiff manages the negotiation between the needs of an image and the
      visual capabilities made available by an X server.  If necessary, it will
      promote an image to a deeper visual, but it will not demote an image by
      quantizing and/or dithering.  In that case it will fail to display the
      image.

      xtiff reads the Gray Response Curve, Gray Response Unit and Color
      Response Curve tags in a TIFF file.  The data in these tags describe
      gamma compensation or image companding.  Together with the -gamma option
      or the NTSC default gamma value of 2.2, the image will be gamma corrected
      and displayed.

      For example, if a TIFF file has been prepared for a typical display, it
      has a gamma compensation of 2.2 built into either the image or preferably
      the Color Response Curve tag.  This is a device-dependent image and, in
      this case, the value for the -gamma command line option should be 1.0.
      If the Color Response Curve tag describes a companded but otherwise
      device-independent image then the command line gamma should be set
      according to the monitor.

      Unfortunately there is no way of knowing a priori whether or not an image
      is device-independent without knowing its ancestry.  If the image
      conforms to the TIFF 5.0 specification it should be device-independent;
      but many scanner and image processing programs do not adhere rigorously
      to the standard.

BUTTONS AND KEYS
      By default, xtiff has certain buttons and keys bound to certain
      functions.



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      Left Mouse Button
              Drags the image around the window.

      N or n  Identical to the Next function.

      N or n  Identical to the Previous function.

      Q or q  Identical to the Quit function.

      arrow keys
              Pressing one of the arrow keys translates the image by an amount
              specified by the translate option.

OPTIONS
      All options are resources and can be set by either the command line or
      the .Xdefaults file.

      -gamma gamma
              Specifies the value used to build compensation tables for simple
              gamma correction.

      -usePixmap (False | True)
              Indicates that xtiff should not use a pixmap to store the image
              on a server.  This option is necessary because some servers
              impose size limitations on pixmaps.  Not using a pixmap is slower
              because the image must be stored on the client side and
              transferred for each exposure or refresh.  Default: True.

      -viewportWidth pixels
              Indicates the width of the image viewport.  Default: 700 or image
              width, whichever is less.

      -viewportHeight pixels
              Indicates the height of the image viewport.  Default: 500 or
              image height, whichever is less.

      -translate pixels
              Indicates the step size that the arrow keys use for translating
              an image.  Default: 20 pixels.

      -verbose (False | True)
              Indicates whether xtiff displays libtiff error messages.
              Default: False.

SEE ALSO
      libtiff(3),
      Tag Image File Format Specification - Revision 5.0, Aldus Corporation,
      August 8, 1988.
      The Spirit of TIFF Class F, Cygnet Technologies, revised March 29, 1990.





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LIMITATIONS
      xtiff does not support the complete repertoire of all possible TIFF files
      on all possible visual/depth combinations.

      xtiff supports TIFF class B (bilevel), class G (grayscale), class P
      (palette color), class R (RGB color) and class F (FAX).

      Only the top-left orientation is supported.  This is both the X
      orientation and the TIFF default.

      Gamma correction is simple and there is no colorimetry support.

      xtiff assumes that servers with 24-bit visuals also have 8-bit visuals.
      An 8-bit image is not promoted to 24-bit on the client side.

      There is no support for StaticGray, StaticColor or TrueColor visuals
      except for 1-bit images.  There is no support for 3/3/2 DirectColor
      visuals.

      When displaying 8-bit images, xtiff creates and populates a private
      colormap with the TIFF colormap or response curve.  Xt will complain
      about failing to allocate colors for the foreground and background
      colors.  xtiff can't allow this because the colormap is already full.  Xt
      should find the nearest substitutes and use them but it doesn't.






























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