CreateZone Method

Description

Create a new zone within the image

Syntax

Visual Basic
Public Function CreateZone( _ Optional ByVal left As Long = 0, _ Optional ByVal top As Long = 0, _ Optional ByVal right As Long = 0, _ Optional ByVal bottom As Long = 0 _ ) As CiImage

Visual Basic

Public Function CreateZone( _
   Optional ByVal left As Long = 0, _
   Optional ByVal top As Long = 0, _
   Optional ByVal right As Long = 0, _
   Optional ByVal bottom As Long = 0 _
) As CiImage

Parameters

left
top
right
bottom

Remarks

The zone's rectangle object should have valid coordinates (right greater than left and bottom greater than top). Otherwise, the zone is considered empty (object.Zone.IsEmpty is true) Invocation of ClearImage methods with an empty zone will generate an error.

Coordinates are inclusive, meaning pixels in the top and bottom rows and the left and right columns belong to the zone. Minimum width and height of the zone are 2 pixels.

Example

VB Example (VB6)

Sub ImageMethods()
  Dim Ci As New CiServer
  Dim image As CiImage: Set image = Ci.CreateImage
    '  Initialize 3000 pixels * 2000 pixels RGB image. All pixels of new RGB image are black.  Default resolution is 1 dpi
  image.CreateBpp 3000, 2000, 24
    '  Set DPI to 200
  image.HorzDpi = 200: image.VertDpi = 200
    '  Crop area of the image
  image.Crop 100, 200, 800, 1000
    '  Initialize 8.5" by 11" bi-tonal image. All pixels of new Bi-tonal image are white.  Default resolution is 300 dpi
    '  Image initialization closes and frees memory of the previously crated RGB image
  image.Create 8.5 * 300, 11 * 300
    '  Convert to grayscale
  image.ToGrayscale
    '  Create zone in the center of the image
  Dim zoneCenter As CiImage
  Set zoneCenter = image.CreateZone(image.Width / 3, image.Height / 3, _
                image.Width * 2 / 3, image.Height * 2 / 3)
    '  Invert center area of the image
  zoneCenter.Invert
    '  Re-define zone to upper left quadrant of the image
  Dim rect As CiRect: Set rect = Ci.CreateRect
  rect.Left = 0: rect.Right = image.Width / 2
  rect.Top = 0: rect.bottom = image.Height / 2
  Dim zoneCorner As CiImage
  Set zoneCorner = image.CreateZoneRect(rect)
    '  Clear corner area on the image
  zoneCorner.Clear
    '  Duplicate center area to a new image
  Dim imageCenter As CiImage
  Set imageCenter = zoneCenter.Duplicate
    '  Copy from the original image
  Dim imageCopy As CiImage: Set imageCopy = Ci.CreateImage
  imageCopy.Copy image
    '  Convert image to bi-tonal
  imageCopy.ToBitonal
    '  Clean-up. Free image memory
  image.Close
  imageCenter.Close
  imageCopy.Close
End Sub