xhistogram

Name

xhistogram - Show the histogram of an image.

Syntax

 #include <xite/Xhistogram.h>

 void xhistogram( Widget wid, IMAGE image,
    IBAND band, Colormap map, int planes,
    ximage_display_func display_func,
    image_callbacks *callbacks );

Description

xhistogram displays a histogram widget. The disp argument supplies a function which is called when the "Send image"-button is pressed, to send a histogram- manipulated image back to xshow as a new image widget. This display function is stored in the global variable dispfunc_s.

xhistogram calls mkHisto(3) for an unsigned byte band and mkDhistogram(3) for other pixel types.

A copy of the currently active colortable is added to the Colors menu of the image. The reduced-color version in the pixel range [64..191] is changed to gray-scale, and this colortable becomes the active one for the histogram window, as well as for the image window.

A special set of colors is installed in some entries outside the pixel range [64..191] of the colormap (in the overlay color entries). Some of these are used to give the correct colors to the primary manipulating lines available when a non-Gray Mode is chosen. By insisting on a visible overlay on top of the image, the overlay colors may therefore be incorrect.

Return value

None

Author

Otto Milvang

Revised

Svein Bře

Doc