 
    
        |  | This menu controls how the image is displayed on your
        screen. None of these commands actually modify the
        image itself, only how it is presented. | 
     
- Returns the displayed image to its 'raw' state (where
        each pixel in the displayed image is as close as possible
        to the corresponding pixel in the internal image). In
        short, it turns off any dithering or smoothing. This
        command is normally disabled, and is only enabled after
        you have issued a Dithered or Smooth
        command.
-  
 
- Regenerates the displayed image by dithering with the
        available colors in an attempt to approximate the
        original image. This has a useful effect only if
        the color allocation code failed to get all the colors it
        wanted. If it did get all the desired colors, the Dither
        command will just generate the same display image as the Raw
        command. On the other hand, if you didn't get all the
        desired colors, the Dither command will try to
        approximate the missing colors by dithering with the
        colors that were obtained, which can help
        eliminate visible banding, and such. Note: If you are
        running xv on a 1-bit display the Dither
        command will be disabled, as the image will always be
        dithered for display.
-  
 
- Smoothes out distortion caused by integer round-off when
        an image is expanded or shrunk. This is generally a
        desirable effect, however it can be fairly time-consuming
        on large images, so by default it is not done
        automatically. See "Modifying
        xv Behavior" for more details. Note that Smooth
        only has a useful effect if the image has been
        resized. If the image is being displayed at its normal
        1:1 expansion ratio, then the Smooth command will
        not have a useful effect. Note: if you are currently
        in '24-bit mode' (see "The 24/8 Bit Menu"
        for more info), the Dithered command is disabled, Raw
        displays the image (dithered on an 8-bit display), and Smooth
        displays a smoothed version of the image (dithered on an
        8-bit display). 
     
- When turned on, forces xv to use read/write color
        cells (ignored and disabled in Use Std. Colormap
        mode, below).. Normally, xv allocates read-only
        color cells, which allows it to share colors with other
        programs. If you use read/write color cells, no other
        program can use the colormap entries that xv is
        using, and vice-versa. The major advantage is that using
        read/write color cells allows the Apply function
        in the xv color editor window to operate much
        faster, and allows the Auto-Apply while dragging
        feature to be used at all. Also note that this command is
        only enabled if you are running xv on a PseudoColor
        display. See "Color
        Allocation in xv" for more
        information on display modes. 
-  
 
- xv's normal color allocation mode. For any given
        picture, xv figures out what colors should be
        allocated, and tries to allocate them (read-only, or
        read/write, as determined by the Read/Write Colors
        setting). If any color allocation fails, xv will
        try a few other tricks, and generally just map the
        remaining colors (the ones it didn't get) into the closest
        colors that it did get. 
-  
 
- When Perfect Colors is turned on, xv
        proceeds as in the Normal Colors case. If any
        color allocation request fails, all colors are freed, and
        xv creates itself a private colormap, and tries
        all over again. It is assumed that having a private
        colormap will provide more colors than allocating out of
        the already partially-used system default colormap. 
-  
 
- Like Perfect Colors , but it doesn't even try
        to allocate out of the system colormap. Instead, it
        starts off by creating its own colormap, and allocating
        from there. Slightly faster than Perfect Colors
        mode. Also useful, as certain X servers (AIX 3.1 running
        on an RS6000, for instance) never report an
        allocation error for read-only color cells. They just
        return the closest color found in the system colormap.
        Generally nice behavior, but it prevents Perfect
        Colors mode from ever allocating a colormap... 
-  
 
- An entirely different color allocation mode. Instead of
        picking the (generally unique) colors that each image
        requires, this mode forces all images to be displayed
        (dithered) using the same set of (standard) colors. The
        downside is that the images don't look as nice as they do
        in the other modes. The upside is that you can display
        many images simultaneously (by running more than one copy
        of xv) without instantly running out of colors.
        The setting of Read/Write Colors is ignored while
        in this mode. Also, this mode is the only one available
        when you are displaying images in 24-bit mode. 
    
        |  | While xv normally displays an
        image in its own window, it is also possible for it to
        display images on the root window (a.k.a. 'the
        desktop'). You would normally use this feature from the
        command- line, as part of some sort of X startup script,
        to put up a background pattern or image of your choice.
        See "Root
        Window Options" for further information on the
        relevant command-line options. You can also specify
        root display options interactively, while the program is
        running, by using the Root menu, as shown. | 
One note regarding root display: it is not possible for xv
to receive button presses or keyboard presses in the root window.
As such, there are several functions that cannot be used while in
a 'root' mode, such as pixel tracking, image editing, pan and
zoom operations, etc. If you want to do such things, you'll have
to temporarily return to 'window' mode, and return to 'root' mode
when you're finished. Also, when you are in a 'root' mode, you
will not be able to get rid of the xv controls
window. At best you can iconify it (using your window manager).
There's a good reason for this. If you could get rid of
the window, there would be no way to ever get it back (since it
won't see keypresses or mouse clicks in the root window).
One other note: If you are running xv on certain 24-bit
displays, where the 'default' visual type is an 8-bit
PseudoColor, but xv in its cleverness has decided to use a
24-bit TrueColor mode, you will not be able to switch the
display to a root mode. This is because xv requires the
visual used in the 'window' mode to be the same as the visual
used for the 'root' modes. In the case of these types of
displays, it is not possible to put a 24-bit TrueColor image on
the root window. You can get this to work by using the ' -visual
default ' command-line option, which will force xv to
use the 'default' visual for both the 'window' and 'root' modes.
Also note: This is only necessary to get this menu to work on
such displays. If you use the '-root' or '-rmode'
command-line options, xv will automatically use patented
"DoTheRightThing" technology...
     
- Displays the image in a window. If you were previously in
        a 'root' mode, the root window will also be cleared.
-  
 
- The image is displayed in the root window. One image is
        displayed aligned with the top-left corner of the screen.
        The image is then duplicated towards the bottom and right
        edges of the screen, as many times as necessary to fill
        the screen. 
-  
 
- Similar to Root: Tiled, except that the image is
        first shrunk so that its width and height are integer
        divisors of the screen's width and height. This keeps the
        images along the bottom and right edges of the screen
        from being 'chopped-off'. Note: using any of the
        'resizing' commands (such as Normal, Double
        Size, etc.) will lose the 'integer'-ness of the
        image, and you'll have to re-select this mode to
        'integer-ify' the image again.  
 
- Tiles the original image with versions that have been
        horizontally flipped, vertically flipped, and both
        horizontally and vertically flipped. This gets rid of the
        sharp dividing lines where tiled images meet. The effect
        is quite interesting. 
-  
 
- Like Root: Mirrored, but also does the
        integer-ization described under the Root: Integer
        Tiled entry. 
-  
 
- Like Root: Tiled, but it positions the images so
        that one of them is centered on the screen, and the rest
        are tiled off in all directions. Visually pleasing
        without the image size distortion associated with Root:
        Integer Tiled . 
-  
 
- Displays a single image centered in the root window,
        surrounded by black, or your choice of any other solid
        color. (See "Modifying
        xv Behavior " for more information.) 
-  
 
- Displays a single image centered in the root window,
        surrounded by a black and white 'warp' pattern, which
        produces some mildly visually pleasing Moir effects. The
        colors can also be chosen by the user. (See "Modifying
        xv Behavior" for details.) 
-  
 
- Displays a single image centered in the root window,
        surrounded by a black and white 'brick' pattern. Again,
        the colors can be set by the user. 
-  
 
- Tiles images on the root window such that the images are
        symmetric around the horizontal and vertical center lines
        of the screen. 
-  
 
- Like the Root: symmetrical tiled mode, but the
        images are also mirrored. 
Note: The three 'centered' modes (Root: Centered , Root:
Centered, Warp, and Root: Centered, Brick, but not Root:
Center Tiled) require the creation of a Pixmap the size of
the screen. This can be a fairly large request for resources, and
will fail on a color X terminal with insufficient memory. They
can also require the transmission of considerably more data than
the other 'root' modes. If you're on a brain-damaged X terminal
hanging off a slow network, you should probably go somewhere
else. Barring that, you should certainly avoid the 'centered'
modes.
Also note: If you quit xv while displaying an image on
the root window, the image will remain in the root window, and
the colors used by the image will remain allocated. This is
generally regarded as correct behavior. If you decide you want to
get rid of the root image to free up resources, or simply because
you're sick of seeing it, the quickest route is to run 'xv
-clear', which will clear the root window, release any
allocated colors, and exit. Alternately, xsetroot or any
other X program that puts things in the root window should be
able to do the trick as well.
