画像／動画認識のComputer Vision APIをOCRとして使うには？　フォントごとの精度は？：認識系API活用入門（5）（3/4 ページ）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
// 追加
using System.Runtime.Serialization;
 
namespace ComputerVisionAPI
{
    [DataContract]
    class OCRResult
    {
        [DataMember]
        public string language { get; set; }
        [DataMember]
        public float textAngle { get; set; }
        [DataMember]
        public string orientation { get; set; }
        [DataMember]
        public Region[] regions { get; set; }
 
        [DataContract]
        public class Region
        {
            [DataMember]
            public string boundingBox { get; set; }
            [DataMember]
            public Line[] lines { get; set; }
        }
 
        [DataContract]
        public class Line
        {
            [DataMember]
            public string boundingBox { get; set; }
            [DataMember]
            public Word[] words { get; set; }
        }
 
        [DataContract]
        public class Word
        {
            [DataMember]
            public string boundingBox { get; set; }
            [DataMember]
            public string text { get; set; }
        }
 
    }
}

        private OCRResult GetOCRResult(string pAccessKey, string pLanguage, string pFile)
        {
            try
            {
                string url = " https://westus.api.cognitive.microsoft.com/vision/v1.0/ocr";
                if(pLanguage != null && pLanguage != "") url += "?language=" + pLanguage;
 
                // リクエスト作成
                HttpWebRequest request = WebRequest.CreateHttp(url);
                request.Method = "POST";
                request.ContentType = "application/octet-stream";
                request.Headers.Add("Ocp-Apim-Subscription-Key", pAccessKey);
 
                // 画像ファイルの読み込み
                FileStream fs = new FileStream(pFile, FileMode.Open, FileAccess.Read);
                byte[] bs = new byte[fs.Length];
                fs.Read(bs, 0, bs.Length);
                fs.Close();
 
                Stream writer = request.GetRequestStream();
                writer.Write(bs, 0, bs.Length);
 
                WebResponse webResponse = request.GetResponse();
                Stream responseStream = webResponse.GetResponseStream();
 
                DataContractJsonSerializer dcjs = new DataContractJsonSerializer(typeof(OCRResult));
                OCRResult result = (OCRResult)dcjs.ReadObject(responseStream);
 
                return result;
 
            }
            catch(WebException webException)
            {
 
                Stream responseStream = webException.Response.GetResponseStream();
                StreamReader streamReader = new StreamReader(responseStream);
                tboxResult.Text = streamReader.ReadToEnd();
                return null;
            }
            catch(Exception exception)
            {
                tboxResult.Text = exception.Message;
                return null;
            }
 
        }