TImageEnProc.CalcOrientation

Declaration

function CalcOrientation(): Integer;

Description

Find the correct orientation for a textual image. It is mainly used to detect whether to adjust a document from portrait to landscape.
It will return either 0 (document is correctly oriented) or 90 (image is right-rotated and should be rotated 90° CCW.
CalcOrientation uses an algorithm that is based on histogram density, without understanding the content of the document. It can only detect 0° or 90° orientation. It cannot detect documents that are inverted, and will give an inaccurate result (90) for documents that are left-rotated.
For more accurate orientation detection, use: getOrientation.

Note: Apply only to document images (images that contain only text)

Demo

Demos\ImageEditing\EveryMethod\EveryMethod.dpr

Example

// Load test image
ImageEnView1.IO.LoadFromFile( 'D:\TestImage.jpg' );

// Automatically rotate a document
n := ImageEnView1.Proc.CalcOrientation();
ImageEnView1.Proc.Rotate( n );

TImageEnProc.CalcOrientation