Class OneOcrService

OneOCR engine implementation of IOCRService using P/Invoke into the native oneocr.dll (Windows 11 SnippingTool OCR engine). No WinRT, no Windows App SDK, no package identity required. Pass engine settings directly to CreateSessionAsync(IReadOnlyDictionary<string, object>, CancellationToken).

Inheritance

object

OneOcrService

Implements

IOCRService

IDisposable

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Zaya.OCR.Impl.OneOcr

Assembly: Zaya.OCR.Impl.OneOcr.dll

Syntax

public sealed class OneOcrService : IOCRService, IDisposable

Remarks

EngineId is oneocr. Settings are exposed via Settings as SettingDescriptor instances for UI hosts, and accepted as a string-keyed dictionary by CreateSessionAsync(IReadOnlyDictionary<string, object>, CancellationToken). Use OneOcrConfig for a typed alternative.

Setting keys

Key	Type	Default	Description
`source`	enum string	`auto`	Where to load engine files from. Values: `auto` (SnippingTool, then URL fallback), `snippingtool`, `directory`, `url`.
`directoryPath`	directory path	(none)	Local folder with `oneocr.dll`, `onnxruntime.dll`, and `oneocr.onemodel`. Required when `source` is `directory`.
`downloadUrl`	URL	GitHub `Zaya.External` OneOCR.zip release	Package URL used when `source` is `url`, and as fallback when `source` is `auto`.
`cacheDirectory`	directory path	`%TEMP%\Zaya\OneOcr`	Writable cache for copied/extracted engine files (`auto`, `snippingtool`, `url`). Hosts such as ScreenTranslator may override this key.
`minConfidence`	integer 0–100	`70`	Minimum word confidence (percent). Words below the threshold are dropped.

Example:

using var ocr = new OneOcrService();
using var session = await ocr.CreateSessionAsync(new Dictionary<string, object>
{
    ["source"] = "auto",
    ["minConfidence"] = 50,
});
var result = await session.RecognizeAsync(image);

Constructors

| Edit this page View Source

OneOcrService()

Initializes a new instance using Zaya.Logging.Services.EmptyLoggingWrapper.Instance.

Declaration

public OneOcrService()

| Edit this page View Source

OneOcrService(ILoggingWrapper)

Initializes a new instance with the specified logging wrapper.

Declaration

public OneOcrService(ILoggingWrapper loggingWrapper)

Parameters

Type	Name	Description
ILoggingWrapper	loggingWrapper	Logging wrapper used when creating sessions.

Properties

| Edit this page View Source

Description

Gets the UI description for this engine (localized).

Declaration

public LocalizedString Description { get; }

Property Value

Type	Description
LocalizedString

| Edit this page View Source

DisplayName

Gets the UI display name for this engine (localized).

Declaration

public LocalizedString DisplayName { get; }

Property Value

Type	Description
LocalizedString

| Edit this page View Source

EngineId

Gets a unique identifier for this OCR engine (e.g., "oneocr", "tesseract"). Used for profile serialization and engine lookup.

Declaration

public string EngineId { get; }

Property Value

Type	Description
string

| Edit this page View Source

IsAvailable

Gets whether this OCR engine is available on the current system.

Declaration

public bool IsAvailable { get; }

Property Value

Type	Description
bool

| Edit this page View Source

PreferredPixelFormat

Gets the pixel format preferred by this OCR engine. The caller (e.g., a screenshot module) can use this to deliver pixels in the optimal format without extra conversion.

Declaration

public PixelFormat PreferredPixelFormat { get; }

Property Value

Type	Description
PixelFormat

| Edit this page View Source

Settings

Gets the engine-specific settings declared by OneOCR (source, directoryPath, downloadUrl, cacheDirectory, minConfidence).

Declaration

public IReadOnlyList<SettingDescriptor> Settings { get; }

Property Value

Type	Description
IReadOnlyList<SettingDescriptor>

Remarks

See the type-level remarks on OneOcrService for key names, defaults, and visibility rules.

Methods

| Edit this page View Source

CreateSessionAsync(IReadOnlyDictionary<string, object>, CancellationToken)

Creates a new OCR session with the specified engine settings.

Declaration

public Task<IOCRSession> CreateSessionAsync(IReadOnlyDictionary<string, object> settings, CancellationToken cancellationToken = default)

Parameters

Type	Name	Description
IReadOnlyDictionary<string, object>	settings	Dictionary of setting keys (see type-level remarks). Missing keys use descriptor defaults.
CancellationToken	cancellationToken	Token to cancel session creation (e.g. while downloading).

Returns

Type	Description
Task<IOCRSession>	An active OCR session ready to recognize text.

| Edit this page View Source

CreateSessionAsync(CancellationToken)

Creates a new OCR session with the default engine settings.

Declaration

public Task<IOCRSession> CreateSessionAsync(CancellationToken cancellationToken = default)

Parameters

Type	Name	Description
CancellationToken	cancellationToken	Token to cancel session creation.

Returns

Type	Description
Task<IOCRSession>	An active OCR session ready to recognize text.

| Edit this page View Source

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

Declaration

public void Dispose()

Implements

IOCRService

IDisposable