Name

---

      CW_HISTOSTRETCH__DEFINE

Purpose

---

      The purpose of this routine is to implement a histogram stretch interactive
      widget for images.

Authors

---

        FANNING SOFTWARE CONSULTING BURRIDGE COMPUTING
        1645 Sheely Drive 18 The Green South
        Fort Collins Warborough, Oxon
        CO 80526 USA OX10 7DN, ENGLAND
        Phone: 970-221-0438 Phone: +44 (0)1865 858279
        E-mail: davidf@dfanning.com E-mail: davidb@burridgecomputing.co.uk

Category

---

      Objects.

Syntax

---

      tlb = Obj_New("TOPLEVELBASE")
      stretch = Obj_New('CW_HISTOSTRETCH', tlb, imageObject)

Superclasses

---

      BASEWIDGET
      WIDGETATOM
      CATATOM
      CATCONTAINER
      IDL_CONTAINER

Class Structure

---

  class = { CW_HISTOSTRETCH, $
            image: Obj_New(), $ ; The image object we are interacting with.
            drawID: Obj_New(), $ ; The draw widget object.
            pixmapID: Obj_New(), $ ; The pixmap widget object.
            minThresh: 0.0, $ ; The minimum threshold.
            maxThresh: 0.0, $ ; The maximum threshold.
            cenThresh: 0.0, $ ; The center of the threshold range.
            minTextID: Obj_New(), $ ; The minimum Text Widget.
            maxTextID: Obj_New(), $ ; The maximum Text Widget.
            cenTextID: Obj_New(), $ ; The center Text Widget.
            format: "", $ ; The string text format.
            colors: Obj_New(), $ ; A colortool object.
            coords: Obj_New(), $ ; A coordinates object.
            xdata: Ptr_New(), $ ; The X data for the histogram plot.
            histoplot: Ptr_New(), $ ; The histogram plot data itself.
            closeto: 0.0, $ ; A delta for establishing if you are "close" to a line.
            lineToMove: "", $ ; A string identifying which line we should move. MIN, MAX, CENTER.
            range: FltArr(2), $ ; The range of the histogram plot.
            INHERITS BASEWIDGET $ ; Inherits base widget capability.
          }

Messages

---

      A message with a title of 'HISTOSTRETCH_CHANGE is sent whenever there is a change in
      a histogram threshold line. The image object passed into the INIT method is automatically
      registered to receive these messages. The DATA passed with the message contains the
      minumum and maximum threshold values, like this:
        DATA={maxThresh:self.maxThresh, minThresh:self.minThresh}

Modification History

---

      Written by: David Fanning, July 17, 2003.