Class OcrFilters
A collection of OCR Image filter for processing Images.
Inheritance
Namespace: IronOcr
Assembly: IronOcr.dll
Syntax
public sealed class OcrFilters : EnumFields
AdaptiveThreshold
Applies Bradley Adaptive Threshold to the image.
Declaration
public const OcrFilters AdaptiveThresholdField Value
| Type | Description |
|---|---|
| OcrFilters |
Binarize
This image filter turns every pixel black or white with no middle ground. May Improve OCR performance cases of very low contrast of text to background.
Declaration
public const OcrFilters BinarizeField Value
| Type | Description |
|---|---|
| OcrFilters |
Close
Advanced Morphology. Opposite of Open
Closing is reverse of Opening, Dilation followed by Erosion. It is useful in closing small holes inside the foreground objects.
Declaration
public const OcrFilters CloseField Value
| Type | Description |
|---|---|
| OcrFilters |
Contrast
Increases contrast automatically. This filter often improves OCR speed and accuracy in low contrast scans.
Amount which is used to adjust contrast. A value of 0 will create an image that is completely gray. A value of 1 leaves the input unchanged.
Amount values greater than 0 increase contrast making light areas lighter and dark areas darker.
Amount values less than 0 decrease contrast - decreasing variety of contrast.
Declaration
public const OcrFilters ContrastField Value
| Type | Description |
|---|---|
| OcrFilters |
DeNoise
Removes digital noise. This filter should only be used where noise is expected. Flattens Alpha channels to white.
Declaration
public const OcrFilters DeNoiseField Value
| Type | Description |
|---|---|
| OcrFilters |
Deskew
Rotates an image so it is the right way up and orthogonal . This is very useful for OCR because Tesseract tolerance for skewed scans can be as low as 5 degrees.
This also helps when producing searchable PDF documents from IronTesseract because the pages will likely all be the right way up.
This version uses only Hough transform to make minor correction. Example: pages that where put in a scanner at a slight angle.
Declaration
public const OcrFilters DeskewField Value
| Type | Description |
|---|---|
| OcrFilters |
Dilate
Advanced Morphology. Opposite of Erode.
Declaration
public const OcrFilters DilateField Value
| Type | Description |
|---|---|
| OcrFilters |
Erode
Advanced Morphology. Opposite of Dilate.
Declaration
public const OcrFilters ErodeField Value
| Type | Description |
|---|---|
| OcrFilters |
Invert
Inverts every color. E.g. White becomes black : black becomes white.
Declaration
public const OcrFilters InvertField Value
| Type | Description |
|---|---|
| OcrFilters |
None
No filter for processing images.
Declaration
public const OcrFilters NoneField Value
| Type | Description |
|---|---|
| OcrFilters |
Open
Advanced Morphology. Opposite of Close
Opening is just another name of erosion followed by dilation. It is useful in removing noise.
Declaration
public const OcrFilters OpenField Value
| Type | Description |
|---|---|
| OcrFilters |
Rotate
Rotates images by a number of degrees clockwise. For anti-clockwise, use negative numbers.
Declaration
public const OcrFilters RotateField Value
| Type | Description |
|---|---|
| OcrFilters |
Scale
Scales images up in size by specify width and height.
Declaration
public const OcrFilters ScaleField Value
| Type | Description |
|---|---|
| OcrFilters |
Sharpen
Sharpens blurred OCR Documents. Applies a Gaussian sharpening filter to image.
Declaration
public const OcrFilters SharpenField Value
| Type | Description |
|---|---|
| OcrFilters |
value__
Declaration
public int value__Field Value
| Type | Description |
|---|---|
| System.Int32 |