Pre-Process the Image

Before recognizing an image, API methods can be used to apply some image pre-processing procedures to enhance the quality of an image resulting in more accurate auto-zoning and recognition. This is typically done with the ImGearRecImage.Preprocess Method, which can include any or all of the following steps:

Inversion: automatic, programmed or none
Rotation: automatic, programmed or none
Deskewing: automatic, automatic 3D perspective, programmed or none

The following properties of ImGearRecPreprocessingSettings Class let you define the behavior of these image enhancement steps:

In addition to these, sometimes image despeckling and resolution enhancement are also performed internally to improve the success of the above transformations.

The Asian Recognition module offers additional settings for automatic deskewing and orientation. See the Asian Recognition Module topic for more details.

Example

Pre-processing an image to deskew it by a set value with the ImGearRecImage.Preprocess Method:

C#	Copy Code
igRecognition.Preprocessing.DeskewMode = ImGearRecDeskewMode.SET; igRecognition.Preprocessing.SkewAmount = 82; igRecPage.Image.Preprocess();

VB .NET	Copy Code
igRecognition.Preprocessing.DeskewMode = ImGearRecDeskewMode.[SET] igRecognition.Preprocessing.SkewAmount = 82 igRecPage.Image.Preprocess()

The image pre-processing methods can also be called one by one. In your code you can use pre-processing methods of ImGearRecImage such as Invert Method, Orient Method, Deskew Method, and Deskew3D Method. When the application calls any of these methods, the appropriate image enhancement step is immediately performed on the image, and the result is available to both the recognition engine and the application. These methods do not have progress monitoring facilities.

These sections provide a summary of information on each image modification step: