TIEVisionOCR.getOrientation

Declaration

procedure getOrientation(out orientation: TIEVisionOCROrientation; out writingDirection: TIEVisionOCRWritingDirection; out textlineOrder: TIEVisionOCRTextlineOrder; out deskewAngle: single); safecall;

Description

Returns detail of the orientation, rotation and text direction of the document. This can be used for non-OCR applications, such as automatically correcting the rotation of scanned documents.
getOrientation must be called after getTextAngle or recognize.

Parameter	Description
orientation	Character orientation, mainly used for document orientation, e.g. a page scanned upside-down would return ievOCROrientPAGE_DOWN
writingDirection	Writing direction
textlineOrder	Line direction, e.g. Right-to-left for Arabic or Hebrew, or Top-to-bottom for some Asian text
deskewAngle	Deskew angle in radians in the range -Pi/4 and Pi/4. The level of rotation required to correct a document scanned at an angle

Note:
◼A shortcut method for this is available: OCR_GetOrientation
◼getOrientation works best with the ievOCRAuto_OSD segmentation mode
◼getOrientation requires the support file Osd.TrainedData for all languages

Example

// AUTOMATICALLY ROTATE CURRENT DOCUMENT IMAGE TO CORRECT ORIENTATION

// Create OCR Engine
m_OCR := IEVisionLib.createOCR( sOcrFilesPath, IEOCRLanguageList[ OCR_English_language ].Code, ievOCRDefault );

// Detect orientation
m_OCR.setSegmentationMode( ievOCRAuto_OSD );
m_OCR.getTextAngle( ImageEnView1.IEBitmap.GetIEVisionImage() ); // Must call either getTextAngle() or recognize() before GetOrientation()

// Retrieve orientation details
m_OCR.getOrientation( orientation, writingDirection, textlineOrder, deskewAngle );

{
Results for above image:
  orientation      : ievOCROrientPAGE_RIGHT
  writingDirection : ievOCRWritDirLEFT_TO_RIGHT
  textlineOrder    : ievOCRTxtlineOrderTOP_TO_BOTTOM
  deskewAngle      : -2.94 rad. (which is -1.5 deg.)
}

// Calculate rotation angle
rotAngle := -deskewAngle * 180 / PI;
if orientation = ievOCROrientPAGE_RIGHT then
  rotAngle := rotAngle - 90
else
if orientation = ievOCROrientPAGE_DOWN then
  rotAngle := rotAngle - 180
else
if orientation = ievOCROrientPAGE_LEFT then
  rotAngle := rotAngle - 270;

{
Result for above image:
  rotAngle : -92.94 deg.
}

// Now rotate the image
if rotAngle <> 0 then
  ImageEnView1.Proc.Rotate( -rotAngle );

TIEVisionOCR.getOrientation