API ref for Text Recognition APIs in the Windows App SDK
Learn about the new Artificial Intelligence (AI) text recognition APIs that will ship with Windows App SDK 1.6 Experimental 2 and can be used to identify characters in an image, recognize words, lines, polygonal boundaries, and provide confidence levels for the generated matches.
For more details, see Text Recognition in the Windows App SDK.
Important
The experimental channel includes APIs and features in early stages of development. All APIs in the experimental channel are subject to extensive revisions and breaking changes and may be removed from subsequent releases at any time. They are not supported for use in production environments, and apps that use experimental features cannot be published to the Microsoft Store.
Microsoft.Windows.Vision namespace
Provides APIs for machine learning models that analyze the textual content of images.
Microsoft.Windows.Vision.TextRecognition.BoundingBox struct
public struct BoundingBox
A polygon with 4 points used for the boundary of recognized words and lines of text.
Fields
BottomLeft
The bottom left corner of the bounding box.
BottomRight
The bottom right corner of the bounding box.
TopLeft
The top left point of the bounding box.
TopRight
The top right point of the bounding box.
Remarks
When returned as a boundary for a word or line, the TopLeft, TopRight, BottomRight, and BottomLeft points are relative to the rotation and skew of the recognized text in the image. The following diagram shows the point layout for different text rotations where 0 is TopLeft, 1 is TopRight, 2 is BottomRight, and 3 is BottomLeft, all relative to the text.
Microsoft.Windows.Vision.DetectedLineStyle enum
public enum DetectedLineStyle
Specifies the line styles that can be recognized.
Enum fields
Handwritten: 0
The line of text is hand written.
Other: 1
The line of text is not hand written.
Microsoft.Windows.Vision.OrientationDetectionOptions enum
public enum OrientationDetectionOptions
Specifies the text orientations that can be recognized.
Enum fields
None: 0
Orientation is not recognized.
DetectOrientation: 1
Orientation is recognized.
Microsoft.Windows.Vision.RecognizedLine class
public sealed class RecognizedLine
Represents a single line of recognized text.
Microsoft.Windows.Vision.RecognizedLine.Style property
public Microsoft.Windows.Vision.RecognizedLineStyle Style { get; }
Gets the recognized line style.
Property value
the recognized line style.
Remarks
Includes whether the line of text was handwritten or not and the level of recognition confidence.
Microsoft.Windows.Vision.RecognizedLine.Text property
public string Text { get; }
Gets the text of the recognized line.
Property value
The text of the recognized line.
Remarks
All words concatenated with spaces.
Microsoft.Windows.Vision.RecognizedLine.Words property
public Microsoft.Windows.Vision.RecognizedWord[] Words { get; }
The words in the recognized line.
Property value
The words in the recognized line.
Microsoft.Windows.Vision.RecognizedLineStyle struct
public struct RecognizedLineStyle
Represents the style of the recognized line.
Struct fields
Confidence
The confidence level of the line style recognition.
Name
The line style name.
Microsoft.Windows.Vision.RecognizedText class
public sealed class RecognizedText
Represents the result of an image-to-text recognition operation.
Microsoft.Windows.Vision.RecognizedText.ImageAngle property
public float ImageAngle { get; }
Gets the clockwise rotational angle of the recognized text in degrees.
Property value
The clockwise rotational angle of the recognized text in degrees.
Microsoft.Windows.Vision.RecognizedText.Lines property
public Microsoft.Windows.Vision.RecognizedLine[] Lines { get; }
Gets the collection of recognized lines.
Property value
The collection of recognized lines.
Microsoft.Windows.Vision.RecognizedWord class
public sealed class RecognizedWord
Represents a single recognized word.
Microsoft.Windows.Vision.RecognizedWord.BoundingBox property
public Microsoft.Windows.Vision.BoundingBox BoundingBox { get; }
Gets the quadrilateral boundary of the recognized word.
Property value
The quadrilateral boundary of the recognized word. TopLeft is relative to the word's rotation.
Microsoft.Windows.Vision.RecognizedWord.Confidence property
public float Confidence { get; }
Gets how likely this word was recognized correctly.
Property value
Wow likely this word was recognized correctly. Value ranges from 0.0 to 1.0, inclusive.
Microsoft.Windows.Vision.RecognizedWord.Text property
public string Text { get; }
Gets the text of the recognized word.
Property value
The text of the recognized word.
Microsoft.Windows.Vision.TextRecognition.TextRecognizer class
public sealed class TextRecognizer : System.IDisposable
Recognizes words and lines, and their quadrilateral boundaries, in a source image.
Microsoft.Windows.Vision.TextRecognizer.Close method
Disposes of the object and associated resources.
Remarks
Not implemented in C#.
Microsoft.Windows.Vision.TextRecognizer.CreateAsync method
public static Windows.Foundation.IAsyncOperation<Microsoft.Windows.Vision.TextRecognizer> CreateAsync ();
Asynchronously creates a new instance of the TextRecognizer class.
Returns
A new instance of the TextRecognizer class.
This will return an error if GetModelReadyStatus is not Ready.
Microsoft.Windows.Vision.TextRecognizer.IsAvailable method
public static bool IsAvailable ();
Retrieves whether the underlying language model is installed.
Returns
True if the underlying language model is installed. Otherwise, false.
Microsoft.Windows.Vision.TextRecognizer.MakeAvailableAsync method
public static Windows.Foundation.IAsyncOperationWithProgress<Microsoft.Windows.Management.Deployment.PackageDeploymentResult,
Microsoft.Windows.Management.Deployment.PackageDeploymentProgress> MakeAvailableAsync ();
Ensures the underlying language model is installed and available for use.
Returns
An asynchronous action with progress that returns a PackageDeploymentResult on completion.
Microsoft.Windows.Vision.TextRecognizer.RecognizeTextFromImage(Microsoft.Windows.Imaging.ImageBuffer, Microsoft.Windows.Vision.TextRecognizerOptions) method
public Microsoft.Windows.Vision.RecognizedText RecognizeTextFromImage (Microsoft.Windows.Imaging.ImageBuffer imageBuffer,
Microsoft.Windows.Vision.TextRecognizerOptions options);
Recognize text in the provided image.
Parameters
imageBuffer
An uncompressed bitmap.
options
Options for configuring the text recognition model for the TextRecognizer.
Returns
The recognized text.
Microsoft.Windows.Vision.TextRecognizer.RecognizeTextFromImageAsync(Microsoft.Windows.Imaging.ImageBuffer, Microsoft.Windows.Vision.TextRecognizerOptions) method
public Windows.Foundation.IAsyncOperation<Microsoft.Windows.Vision.RecognizedText> RecognizeTextFromImageAsync (Microsoft.Windows.Imaging.ImageBuffer imageBuffer,
Microsoft.Windows.Vision.TextRecognizerOptions options);
Asynchronously recognize text in the provided image.
Parameters
imageBuffer
An uncompressed bitmap.
options
Options for configuring the text recognition model for the TextRecognizer.
Returns
The recognized text.
Microsoft.Windows.Vision.TextRecognizerOptions class
public sealed class TextRecognizerOptions
Provides options to configure the text recognition model for a TextRecognizer.
Microsoft.Windows.Vision.TextRecognizerOptions.MaxAnalysisSize property
public Windows.Graphics.SizeInt32 MaxAnalysisSize { get; set; }
Gets or sets the maximum image size.
Property value
The maximum image size. Default value is 1152 width and 768 height.
Remarks
This size is a suggestion, and might not always be honored.
If the source image is larger than the maximum size, it will automatically be scaled down to the upper size limits.
Microsoft.Windows.Vision.TextRecognizerOptions.MaxLineCount property
public uint MaxLineCount { get; set; }
Gets or sets the maximum number of lines to return from the recognition operation.
Property value
The maximum number of lines to return from the recognition operation.
Remarks
Defaults to MaxLineCountSupported. If specified, the maximum lines returned will be the lesser of this value and MaxLineCountSupported.
Microsoft.Windows.Vision.TextRecognizerOptions.OrientationDetection property
public Microsoft.Windows.Vision.OrientationDetectionOptions OrientationDetection { get; set; }
Gets or sets whether to detect the text orientation.
Property value
Whether to detect the text orientation. Default value is None.
Microsoft.Windows.Vision.TextRecognizerOptions.#ctor constructor
public TextRecognizerOptions ();
Initializes a new instance of the TextRecognizerOptions class.
Microsoft.Windows.Imaging namespace
Provides APIs for machine learning models that manipulate images.
Microsoft.Windows.Imaging.ImageBuffer class
public sealed class ImageBuffer : System.IDisposable
Represents an uncompressed bitmap for efficient cross-process marshaling.
Remarks
ImageBuffer can be used with AI model APIs such as TextRecognizer that require image data. Typical usage involves creating an ImageBuffer from an existing SoftwareBitmap.
Microsoft.Windows.Imaging.ImageBuffer.Buffer property
public Windows.Storage.Streams.IBuffer Buffer { get; }
Gets the current image buffer.
Property value
The current image buffer.
Microsoft.Windows.Imaging.ImageBuffer.BufferLength property
public uint BufferLength { get; }
Gets the length of the image buffer.
Property value
The length of the image buffer.
Microsoft.Windows.Imaging.ImageBuffer.Close method
Disposes of the object and associated resources.
Remarks
Not implemented in C#.
Microsoft.Windows.Imaging.ImageBuffer.CopyToBuffer(System.Byte[]) method
public void CopyToBuffer (byte[] values);
Copies the current buffer into the provided target buffer.
Parameters
values
Vector of bytes in the buffer.
Microsoft.Windows.Imaging.ImageBuffer.CreateBufferAttachedToBitmap(Windows.Graphics.Imaging.SoftwareBitmap) method
public static Microsoft.Windows.Imaging.ImageBuffer CreateBufferAttachedToBitmap (Windows.Graphics.Imaging.SoftwareBitmap softwareBitmap);
Create a new ImageBuffer from an existing SotftwareBitmap by getting an IMemoryBufferReference from the bitmap object.
Parameters
softwareBitmap
The SotftwareBitmap to create the ImageBuffer from.
Returns
The ImageBuffer or null if it's an unsupported format.
Remarks
The SoftwareBitmap is locked until the async operation completes and the new ImageBuffer is destroyed.
Microsoft.Windows.Imaging.ImageBuffer.CreateCopyFromBitmap(Windows.Graphics.Imaging.SoftwareBitmap) method
public static Microsoft.Windows.Imaging.ImageBuffer CreateCopyFromBitmap (Windows.Graphics.Imaging.SoftwareBitmap softwareBitmap);
Create a new ImageBuffer from an existing SotftwareBitmap by copying out the underlying bitmap data.
Parameters
softwareBitmap
The SotftwareBitmap to create the ImageBuffer from.
Returns
The ImageBuffer or null if it's an unsupported format.
Remarks
The SoftwareBitmap is locked until the async operation completes and the new ImageBuffer is destroyed.
Microsoft.Windows.Imaging.ImageBuffer.CreateSoftwareBitmap method
public Windows.Graphics.Imaging.SoftwareBitmap CreateSoftwareBitmap ();
Create a new SoftwareBitmap of pixel type BGRA32 from the pixel data stored in an ImageBuffer.
Returns
The new SoftwareBitmap of pixel type BGRA32.
Microsoft.Windows.Imaging.ImageBuffer.Height property
public uint Height { get; }
Gets the height of the image, in pixels.
Property value
The height of the image, in pixels.
Microsoft.Windows.Imaging.ImageBuffer.#ctor(Windows.Storage.Streams.IBuffer, Microsoft.Windows.Imaging.PixelFormat, System.UInt32, System.UInt32) constructor
public ImageBuffer (Windows.Storage.Streams.IBuffer buffer,
Microsoft.Windows.Imaging.PixelFormat pixelFormat, uint width, uint height);
Initializes a new instance of the ImageBuffer class.
Parameters
buffer
The ImageBuffer.
pixelFormat
The pixel format of the image.
width
The width of the image, in pixels.
height
The height of the image, in pixels.
Microsoft.Windows.Imaging.ImageBuffer.PixelFormat property
public Microsoft.Windows.Imaging.PixelFormat PixelFormat { get; }
Gets the pixel format of the image.
Property value
The pixel format of the image.
Microsoft.Windows.Imaging.ImageBuffer.Width property
public uint Width { get; }
Gets the width of the image, in pixels.
Property value
The width of the image, in pixels.
Microsoft.Windows.Imaging.PixelFormat enum
public enum PixelFormat
Specifies the types of binary layouts for the underlying bitmap data.
Enum fields
Undefined: 0
Binary format is undefined.
Rgb24: 1
The binary format is 24 bits per pixel; 8 bits each are used for the red, green, and blue components.
Argb32: 2
The binary format 32 bits per pixel; 8 bits each are used for the alpha, red, green, and blue components.
Rgba32: 3
The binary format is 32 bits per pixel; 8 bits each are used for the red, green, blue, and alpha components. The color components are stored in red, green, blue, and alpha order.
Bgra32: 4
The binary format is 32 bits per pixel; 8 bits each are used for the blue, green, red, and alpha components. The color components are stored in blue, green, red, and alpha order.
Gray8: 5
The binary format is 16 bits per pixel. The color information specifies 65536 shades of gray.
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