【C#】文字認識をWindows10のOCRでやってみた！

using System.Windows.Media.Imaging;
using Windows.Graphics.Imaging;
using Windows.Media.Ocr;

private async Task<SoftwareBitmap> ConvertSoftwareBitmap(Image image)
{
    SoftwareBitmap sbitmap = null;

    using (MemoryStream stream = new MemoryStream())
    {
        //BmpBitmapEncoderに画像を書きこむ
        var encoder = new BmpBitmapEncoder();
        encoder.Frames.Add((System.Windows.Media.Imaging.BitmapFrame)image.Source);
        encoder.Save(stream);

        //メモリストリームを変換
        var irstream = WindowsRuntimeStreamExtensions.AsRandomAccessStream(stream);

        //画像データをSoftwareBitmapに変換
        var decorder = await Windows.Graphics.Imaging.BitmapDecoder.CreateAsync(irstream);
        sbitmap = await decorder.GetSoftwareBitmapAsync();
    }

    return sbitmap;
}

private async Task<OcrResult> RunOcr(SoftwareBitmap sbitmap)
{
    //OCRを実行する
    OcrEngine engine = OcrEngine.TryCreateFromLanguage(new Windows.Globalization.Language("ja-JP"));
    var result = await engine.RecognizeAsync(sbitmap);
    return result;
}

<Window
    x:Class="OCRsample.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:OCRsample"
    xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Title="MainWindow"
    Width="600"
    Height="450"
    WindowStyle="None"
    mc:Ignorable="d">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="50" />
            <RowDefinition Height="55" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <!--  ヘッダー  -->
        <materialDesign:ColorZone
            Grid.Row="0"
            Height="50"
            Padding="12"
            Mode="PrimaryMid">
            <DockPanel>
                <materialDesign:PopupBox DockPanel.Dock="Right" PlacementMode="BottomAndAlignRightEdges">
                    <ListBox>
                        <ListBoxItem Content="Close" />
                    </ListBox>
                </materialDesign:PopupBox>
                <StackPanel Orientation="Horizontal">
                    <materialDesign:PackIcon
                        Width="26"
                        Height="26"
                        Kind="Ocr" />
                    <TextBlock
                        Margin="16,0,0,0"
                        VerticalAlignment="Center"
                        Text="OCR SAMPLE" />
                </StackPanel>
            </DockPanel>
        </materialDesign:ColorZone>
        <Label
            x:Name="lblPath"
            Grid.Row="1"
            Width="92"
            Margin="10,18,0,0"
            HorizontalAlignment="Left"
            VerticalAlignment="Top"
            HorizontalContentAlignment="Right"
            Content="ファイルパス：" />
        <TextBox
            x:Name="txtPath"
            Grid.Row="1"
            Margin="110,5,175,0"
            VerticalAlignment="Top"
            materialDesign:HintAssist.Hint="イメージファイルのパスを入力してください。"
            Style="{StaticResource MaterialDesignFloatingHintTextBox}" />
        <Button
            Name="btnPath"
            Grid.Row="1"
            Width="70"
            Margin="0,10,100,0"
            HorizontalAlignment="Right"
            VerticalAlignment="Top"
            Click="btnPath_Click"
            Content="参照..."
            FontSize="12"
            Style="{StaticResource MaterialDesignPaperDarkButton}" />
        <Button
            Name="btnOcr"
            Grid.Row="1"
            Width="85"
            Margin="0,10,10,0"
            HorizontalAlignment="Right"
            VerticalAlignment="Top"
            Click="btnOcr_Click"
            Content="OCR実行"
            FontSize="12" />
        <Image
            x:Name="ImgTarget"
            Grid.Row="2"
            Margin="10,10,10,100" />
        <TextBox
            Name="txtOcrResult"
            Grid.Row="2"
            Margin="10,255,10,10"
            VerticalAlignment="Bottom"
            materialDesign:HintAssist.Hint="OCRの実行結果"
            AcceptsReturn="True"
            IsEnabled="{Binding Path=IsChecked, ElementName=MaterialDesignOutlinedTextBoxEnabledComboBox}"
            Style="{StaticResource MaterialDesignOutlinedTextBox}"
            TextWrapping="Wrap"
            VerticalScrollBarVisibility="Auto" />
    </Grid>
</Window>

namespace OCRsample
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private async void btnPath_Click(object sender, RoutedEventArgs e)
        {
            ImgTarget.Source = null;
            txtPath.Text = "";

            await Task.Delay(10);

            //画像ファイルのパスを取得
            txtPath.Text = SelectPath();

            if (txtPath.Text != "")
            {
                //画像ファイルの読み込み
                ImgTarget.Source = System.Windows.Media.Imaging.BitmapFrame.Create(new Uri(txtPath.Text, UriKind.Absolute), BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
            }
        }

        private string SelectPath()
        {
            var path = "";

            // ダイアログのインスタンスを生成
            var dialog = new OpenFileDialog();

            // ファイルの種類を設定
            dialog.Filter = "Image File(*.bmp, *.jpg, *.png, *.tif) | *.bmp; *.jpg; *.png; *.tif | Bitmap(*.bmp) | *.bmp | Jpeg(*.jpg) | *.jpg | PNG(*.png) | *.png";

            // ダイアログを表示する
            if (dialog.ShowDialog() == true)
            {
                // 選択されたファイル名を取得
                path = dialog.FileName;
            }

            return path;
        }

        private async void btnOcr_Click(object sender, RoutedEventArgs e)
        {
            //OCRの実行処理
            var sbitmap = await ConvertSoftwareBitmap(ImgTarget);
            txtOcrResult.Text = (await RunOcr(sbitmap)).Text;
        }
    }
}