1. System.Drawing.Bitmap から SoftwareBitmap を取得する方法
2-1. ソースコード の MakeSoftwareBitmap メソッドの処理で実現可能。
1-1. SoftwareBitmap をプログラムから生成する方法（参考サイト）
ビットマップ画像の作成、編集、保存 - UWP applications | Microsoft Docs
2. C#/WinRT で OCR やってみた - クリップボードから取得版
2-1. ソースコード
以下、C#/WinRT で OCR やってみた - Qiitaからの派生
※SoftwareBitmap側 の RGB の順序が合っているかは裏どりしていない。
using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;
using System.Collections.Generic;
using System.Threading.Tasks;
using Windows.Graphics.Imaging;
using Windows.Media.Ocr;
using Windows.Storage;
using Windows.Storage.Streams;
using Windows.Foundation;
class OcrTest
{
[System.STAThread]
static void Main(string[] args)
{
System.Drawing.Image img = System.Windows.Forms.Clipboard.GetImage();
if (img != null)
{
var bmp = (System.Drawing.Bitmap)img; // 例外が発生する可能性あり
SoftwareBitmap softBmp = MakeSoftwareBitmap(bmp);
Task<string> ret = LoadImageAndOcr(softBmp);
Console.WriteLine(ret.Result);
}
}
[ComImport]
[Guid("5B0D3235-4DBA-4D44-865E-8F1D0E4FD04D")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
unsafe interface IMemoryBufferByteAccess
{
void GetBuffer(out byte* buffer, out uint capacity);
}
static SoftwareBitmap MakeSoftwareBitmap(System.Drawing.Bitmap bmp)
{
unsafe {
var softwareBitmap = new SoftwareBitmap(BitmapPixelFormat.Bgra8, bmp.Width, bmp.Height, BitmapAlphaMode.Premultiplied);
System.Drawing.Imaging.BitmapData bd = bmp.LockBits(new System.Drawing.Rectangle(0, 0, bmp.Width, bmp.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
byte* pSrc = (byte*)bd.Scan0;
using (BitmapBuffer buffer = softwareBitmap.LockBuffer(BitmapBufferAccessMode.Write))
{
using (var reference = buffer.CreateReference())
{
byte* pDest;
uint capacity;
((IMemoryBufferByteAccess)reference).GetBuffer(out pDest, out capacity);
// Fill-in the BGRA plane
BitmapPlaneDescription bl = buffer.GetPlaneDescription(0);
for (int y = 0; y < bl.Height; y++) {
int blOffset = bl.StartIndex + y*bl.Stride;
int yb = y*bd.Stride;
for (int x = 0; x < bl.Width; x++) {
pDest[blOffset + 4*x ] = pSrc[yb + 4*x ]; // blue
pDest[blOffset + 4*x + 1] = pSrc[yb + 4*x + 1]; // green
pDest[blOffset + 4*x + 2] = pSrc[yb + 4*x + 2]; // red
pDest[blOffset + 4*x + 3] = (byte)255; // alpha
}
}
}
}
bmp.UnlockBits(bd);
return softwareBitmap;
}
}
static async Task<OcrResult> detect(SoftwareBitmap bitmap)
{
var ocrEngine = OcrEngine.TryCreateFromUserProfileLanguages();
var ocrResult = await MyWaitUtil<OcrResult>.GetResultWithWaiting( ocrEngine.RecognizeAsync(bitmap) );
// https://docs.microsoft.com/ja-jp/uwp/api/windows.media.ocr.ocrresult.lines?view=winrt-19041
return ocrResult;
}
static async Task<string> LoadImageAndOcr(SoftwareBitmap softwareBitmap)
{
OcrResult t = await detect(softwareBitmap);
return t.Text;
}
}
public static class MyWaitUtil<T>
{
public static async Task<T> GetResultWithWaiting(IAsyncOperation<T> task)
{
while ( task.Status != AsyncStatus.Completed ) {
if ( task.Status == AsyncStatus.Error || task.Status == AsyncStatus.Canceled ) {
Console.WriteLine("Error or Canceled");
return default(T);
}
await Task.Delay(1);
};
return task.GetResults();
}
}
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