ImageProcessingTools Object (IImageProcessingTools Interface)
This object allows you to preprocess images before recognition.
The standard procedure, which uses this object, is as follows:
- Open an image file using either the OpenImageFile or OpenImageFileFromStream method. These methods return an opened file as the ImageFile object.
- Open a page of the image file using the OpenImagePage of the ImageFile object. This method provides access to an image page as the Image object.
- Preprocess the image page using one of the available methods or implement your own preprocessing algorithm. With the available methods you can do the following operations:
- remove noise from color photos (RemoveNoise, CreateDenoiseFilterParamsByImage methods)
- remove motion blur from photos, equalize their brightness (RemoveMotionBlur, EqualizeBrightness methods)
- remove geometrical distortions from an image or stretch it (CorrectImageGeometry, StretchTrapezoidToRectangle, StretchImage methods)
- suppress color objects in official documents (SuppressColorObjects method)
- remove garbage (excess dots that are smaller than a certain size) from an image (RemoveGarbage method)
- smooth image (SmoothImageBySquareAverage, SmoothImageByGaussianKernel methods)
- smooth texture (SmoothTexture method)
- detect orientation of the text on an image and rotate an image either by a predefined angle, or by any custom angle (DetectOrientationByText, RotateImageByRotationType, RotateImage methods)
- mirror or invert an image (MirrorImage, InvertRegion methods)
- crop an image (CropImage method)
- fill with color a region on an image (FillRegionWithColor method)
- convert image to gray or black and white (ConvertToGray, Binarize methods)
- convert an internal image plane to a bitmap and vice versa (ImageToBitmap and BitmapToImage methods)
Methods
Name | Description |
---|---|
Binarize | Converts an image to black and white. |
BitmapToImage | Converts the specified bitmap to the Image object. |
CalcSuitableForOcr | Shows how suitable is an image for OCR. Possible values are from 0.0 to 1.0. |
ConvertToGray | Converts an image to gray. |
CorrectImageGeometry | Corrects image geometry: perspective distortions, curved text lines. |
CreateDenoiseFilterParamsByImage | Measures ISO noise on the image and creates the DenoiseFilterParams object based on the measurement. |
CropImage | Crops an image. |
DetectEmpty | Detects if the image is empty. |
DetectOrientationByText | Detects orientation of an image by text lines. |
DetectRequiredRotation | Detects the rotation that should be applied to the image to return it to the normal (upright) orientation. |
EqualizeBrightness | Equalizes brightness of an image. |
FillRegionWithColor | Fills the specified region with color. |
FilterColor | Removes specified color objects from the entire image or its parts. |
ImageToBitmap | Converts the Image object to a bitmap. |
InvertRegion | Inverts either the specified region on an image or the entire image. |
IsSuitableForOcr | Checks if an image is suitable for OCR. |
MirrorImage | Mirrors an image either vertically or horizontally. |
OpenImageFile | Opens an image file. |
OpenImageFileFromStream | Reads an image file from the specified stream. |
PreprocessCameraImage | Preprocesses a photo using predefined settings specially designed for different types of photos. |
RemoveGarbage | Removes isolated clusters of pixels of the specified size which are considered garbage. |
RemoveMotionBlur | Removes motion blur from an image. |
RemoveNoise | Removes ISO noise from color photos. |
RotateImage | Rotates an image by the specified angle. |
RotateImageByRotationType | Rotates an image by a predefined angle (90 degrees clockwise, 90 degrees counterclockwise, upside down). |
SmoothImageByGaussianKernel | Smoothes an image by Gaussian kernel. |
SmoothImageBySquareAverage | Smoothes the image by averaging over the square neighborhood. |
SmoothTexture | Smoothes texture of an image by a nonlinear filter, preserving sharp edges. |
StretchImage | Stretches or shrinks the image to the specified size. |
StretchTrapezoidToRectangle | Transforms an image so that the specified trapezoid becomes a rectangle. Can be used to manually correct slight perspective distortion. |
SuppressColorObjects | Suppresses objects with the specified color in official documents. |
Output parameter
This object is the output parameter of the CreateImageProcessingTools method of the Engine object.
Samples
C# code
15.08.2023 13:19:30