ImageFeatureDescriptor 类

定义

描述模型预期的图像的属性。

public ref class ImageFeatureDescriptor sealed : ILearningModelFeatureDescriptor
/// [Windows.Foundation.Metadata.ContractVersion(Windows.AI.MachineLearning.MachineLearningContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
class ImageFeatureDescriptor final : ILearningModelFeatureDescriptor
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.AI.MachineLearning.MachineLearningContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
public sealed class ImageFeatureDescriptor : ILearningModelFeatureDescriptor
Public NotInheritable Class ImageFeatureDescriptor
Implements ILearningModelFeatureDescriptor
继承
Object IInspectable ImageFeatureDescriptor
属性
实现

Windows 要求

设备系列
Windows 10, version 1809 (在 10.0.17763.0 中引入)
API contract
Windows.AI.MachineLearning.MachineLearningContract (在 v1.0 中引入)

示例

以下示例从本地文件加载模型,从该文件创建会话,并获取输入和输出功能。

private async Task LoadModelAsync(string _modelFileName)
{
    LearningModel _model;
    LearningModelSession _session;
    ImageFeatureDescriptor _inputImageDescription;
    TensorFeatureDescriptor _outputImageDescription;

    try
    {
        // Load and create the model
        var modelFile = 
            await StorageFile.GetFileFromApplicationUriAsync(new Uri($"ms-appx:///Assets/{_modelFileName}"));
        _model = await LearningModel.LoadFromStorageFileAsync(modelFile);

        // Create the evaluation session with the model
        _session = new LearningModelSession(_model);

        //Get input and output features of the model
        List<ILearningModelFeatureDescriptor> inputFeatures = _model.InputFeatures.ToList();
        List<ILearningModelFeatureDescriptor> outputFeatures = _model.OutputFeatures.ToList();

        // Retrieve the first input feature which is an image
        _inputImageDescription = inputFeatures.FirstOrDefault(
            feature => feature.Kind == LearningModelFeatureKind.Image) as ImageFeatureDescriptor;

        // Retrieve the first output feature which is a tensor
        _outputImageDescription = outputFeatures.FirstOrDefault(
            feature => feature.Kind == LearningModelFeatureKind.Tensor) as TensorFeatureDescriptor;
    }
    catch (Exception ex)
    {
        StatusBlock.Text = $"error: {ex.Message}";
        _model = null;
    }
}

注解

Windows Server

若要在 Windows Server 上使用此 API,必须使用具有桌面体验的 Windows Server 2019。

线程安全

此 API 是线程安全的。

属性

BitmapAlphaMode

指定图像的预期 alpha 模式。

BitmapPixelFormat

指定 (通道排序、位深度和数据类型) 的预期像素格式。

Description

描述在模型中使用此功能的说明。

Height

预期的图像高度。

IsRequired

如果为 true,则必须在调用 LearningModelSession.Evaluate 之前将值绑定到此功能。

Kind

特征类型 - 使用此类型来了解要使用的派生类。

Name

用于将值绑定到此功能的名称。

PixelRange

提供用于模型的预期 LearningModelPixelRange 信息。

Width

预期的图像宽度。

适用于

另请参阅