SongBee's Image Processing Blablabla

2017年8月2日星期三

搬家了

https://lsongbeeimageprocessingblablabla.wordpress.com/

這裡的文章還是會留著，只是不再更新

2017年7月27日星期四

Linear Neighborhood Propagation 筆記

在影像的應用是以Graph-base來做影像分割(image segmentation), 其特點在於把圖論 G = (V, E)中的 E 建立方式

把常用的

LNPeq1

改良為

LNPeq2

如同演算名所揭示的Neighborhood期以鄰近的資料來推演與標記資料

資料標記化的處理程序為

LNPsteps

參考資料

Semi-Supervised Classification Using Linear Neighborhood Propagation
Label Propagation Through Linear Neighborhoods

參考資料中不懂的幾個名詞或縮寫

LEE (Locally Linear Embedding)
Local Gram matrix
p-Dirichlet
NN (nearest neighbor classifier)
TSVM (transductive SVM)

2015年10月22日星期四

設定OpenCV 3.0 於 VS2012 環境中

1. 為方便稍後的設定與未來專案的移植性，在安裝完OpenCV 3.0後首先要設定OpenCV的環境目錄，使用管理員的權限開啟Command視窗輸入

   1: setx -m OPENCV_DIR e:\sdk\opencv\build

2. 開啟VS2012，匯入我設定好的property setting (OpenCV300.zip)，OpenCV300.props的內容如下：

   1: <?xml version="1.0" encoding="utf-8"?>

   2: <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">

   3:   <ImportGroup Label="PropertySheets" />

   4:   <PropertyGroup Label="UserMacros" />

   5:   <PropertyGroup>

   6:     <IncludePath>$(OPENCV_DIR)\include;$(IncludePath)</IncludePath>

   7:     <LibraryPath Condition="'$(Platform)'=='Win32'">$(OPENCV_DIR)\x86\vc11\staticlib;$(LibraryPath)</LibraryPath>

   8:     <LibraryPath Condition="'$(Platform)'=='X64'">$(OPENCV_DIR)\x64\vc11\staticlib;$(LibraryPath)</LibraryPath>

   9:   </PropertyGroup>

  10:   <ItemDefinitionGroup>

  11:     <Link Condition="'$(Configuration)'=='Debug'">

  12:       <AdditionalDependencies>ippicvmt.lib;IlmImfd.lib;libjasperd.lib;libjpegd.lib;libpngd.lib;libtiffd.lib;libwebpd.lib;opencv_calib3d300d.lib;opencv_core300d.lib;opencv_features2d300d.lib;opencv_flann300d.lib;opencv_hal300d.lib;opencv_highgui300d.lib;opencv_imgcodecs300d.lib;opencv_imgproc300d.lib;opencv_ml300d.lib;opencv_objdetect300d.lib;opencv_photo300d.lib;opencv_shape300d.lib;opencv_stitching300d.lib;opencv_superres300d.lib;opencv_ts300d.lib;opencv_video300d.lib;opencv_videoio300d.lib;opencv_videostab300d.lib;zlibd.lib;%(AdditionalDependencies)</AdditionalDependencies>

  13:     </Link>

  14:     <Link Condition="'$(Configuration)'=='Release'">

  15:       <AdditionalDependencies>ippicvmt.lib;IlmImf.lib;libjasper.lib;libjpeg.lib;libpng.lib;libtiff.lib;libwebp.lib;opencv_calib3d300.lib;opencv_core300.lib;opencv_features2d300.lib;opencv_flann300.lib;opencv_hal300.lib;opencv_highgui300.lib;opencv_imgcodecs300.lib;opencv_imgproc300.lib;opencv_ml300.lib;opencv_objdetect300.lib;opencv_photo300.lib;opencv_shape300.lib;opencv_stitching300.lib;opencv_superres300.lib;opencv_ts300.lib;opencv_video300.lib;opencv_videoio300.lib;opencv_videostab300.lib;zlib.lib;%(AdditionalDependencies)</AdditionalDependencies>

  16:     </Link>

  17:   </ItemDefinitionGroup>

  18:   <ItemGroup />

  19: </Project>

若編譯的環境為VS2013則將上述的設定檔中的vc11改為vc12即可。

由於使用的是static lib所以原專案的runtime library也必需改為/MT或/MTd

2013年12月27日星期五

[W8App][C#] Task Cancellation

若想要讓產生的Task具有可取消的機制，則必需透過以下static methods取得task handle與傳入cancel token來達成
Task.Run(Action, CancellationToken)
Task.Run(Func<Task>, CancellationToken)
Task.Run<TResult>(Func<Task<TResult>>, CancellationToken)
Task.Run<TResult>(Func<TResult>, CancellationToken)

這個範例是我設計的一個對話盒控制項，當對話盒產生時呼叫InitItemsAsync以非同步的方式產生圖片對載入UI的list控制項中，使用者可以不必等待所有的圖片都產生即按下OK(或Cancel)按來關閉這個對話盒。因此我必需讓InitItemsAsync具有可被取消的機制。

   1: public sealed partial class MyDialog : UserControl   2: {   3:     private CancellationTokenSource _cts;   4:     private CancellationToken _token;    5:     private Task _opInit;

#3-5 我們的物件必需儲存CancellationTokenSource、CancellationToken與Task方便在動作的對應函式中取消

   1: private async Task InitItemsAsync()   2: {   3:     for(int i=0 ; i<24 ; i++)   4:     {   5:         if (_token.IsCancellationRequested) break;   6:     7:         await LoadImageAsync(i);   8:     }   9: }

#5 非同步的InitItemsAsync函式，當_token收到取消的要求時(IsCancellationRequested)提前結束迴圈

   1: _cts = new CancellationTokenSource();   2: _token = _cts.Token;   3: _opInit = Task.Run(async () =>   4: {   5:     await InitItemsAsync();   6: },   7: _token);

透過Task.Run來執行非同步的函式，並載入cancel token。
#5 InitItemAsync是非同步的函式，因此必需有async / await來載明

PS: 我嘗試過不用Lambda的寫法，而是直接以函式指標的方式來使用Task.Run，但在VS2013編譯時期會有函式型別模糊(error CS0121: The call is ambiguous between the following methods or properties)的錯誤，目前還不知道解決的方式。

   1: private bool TryCancelInitItems()   2: {   3:     if (_opInit.IsCompleted == false)   4:     {   5:         try   6:         {   7:             _cts.Cancel();   8:     9:             _opInit.Wait(_token);  10:    11:             return true;  12:         }  13:         catch(System.OperationCanceledException)  14:         {  15:             return true;  16:         }  17:         catch (Exception e)  18:         {  19:             Debug.WriteLine(@"{0}", e);  20:    21:             return false;  22:         }  23:     }  24:    25:     return true;  26: }

當使用者按下結束對話盒的按鈕時，呼叫我的TryCancelInitItems函式來取消InitItemsAsync。

#3 先檢查task是否已經完成，若尚未完成才需使用取消機制
#7 呼叫取消並等待_token
#13 若InitItemsAsync被取消了，會丟出System.OperationCanceledException

2013年10月25日星期五

[W8App] 8.0 “Snapped” to 8.1– with LayoutAwarePage

Windows 8.1的一個德政是取消了原本的Snappped View限制，App除了FullScreen外還可以有任意的大小(只是有最小限制)。不過對於已經開發好的8.0 App，就要花時間重新調整不同視窗大小時Layout。

我的懶人改法是，除了FullScreen外一律視為Snapped。依這樣的邏輯其實只要改動一個function – LayoutAwarePage的DetermineVisualState：

   1: protected virtual string DetermineVisualState(ApplicationView appView)   2: {   3:     if(appView.IsFullScreen)   4:     {   5:         return @"FullScreen" + appView.Orientation.ToString();   6:     }   7:     else   8:     {   9:         return @"Snapped";  10:     }  11: }

1. 原本參數為ApplicationViewState (編譯時有warning)，改為ApplicationView
3-10. 原本view state可以直接吐回字串的部份用邏輯修正

當然呼叫端也要調整為

   1: string visualState = DetermineVisualState(ApplicationView.GetForCurrentView());

1. 原本呼叫端是傳入ApplicationView.Value (編譯時有warning)，改為ApplicationView.GetForCurrentView()

2013年10月22日星期二

[W8App] In W8.1, DirectWrite must create font with IDWriteFactory2

升上8.1第一天後, 我的App發生DirectWrite繪製文字有時會繪製不出來的問題。最後才發現改IDWriteFactory改為IDWriteFactory2後就一切正常，不過IDWriteFactory2只支援8.1以上，所以結論是App必做二個版本了。。。

2013年10月14日星期一

[W8App] D2DERR_WRONG_FACTORY (0x88990012)

最近在學習W8App的Direct2D與DirectWrite時發生了一個例外的錯誤，當呼叫D2D的EndDraw來更新繪圖結果是產生了0x88990012 (D2DERR_WRONG_FACTORY)的例外錯誤。

這個錯誤發生的原因是我的DirectWrite Render物件預先儲存了D2D factory，而透過SurfaceImageSource來連結W8App與Direct2D時，D2DContext所使用的D2D factory似乎有自已獨立的產生方式。

目前的解決方式是透過GetFactory直接從D2DContext物件中取得D2DFactory，至於是否有更好的作法，就需要再研究。

   1: IFACEMETHODIMP CustomTextRenderer::DrawGlyphRun(   2:     _In_opt_ void* clientDrawingContext,   3:     FLOAT baselineOriginX,   4:     FLOAT baselineOriginY,   5:     DWRITE_MEASURING_MODE measuringMode,   6:     _In_ DWRITE_GLYPH_RUN const* glyphRun,   7:     _In_ DWRITE_GLYPH_RUN_DESCRIPTION const* glyphRunDescription,   8:     IUnknown* clientDrawingEffect   9:     )  10: {  11:     HRESULT hr = S_OK;  12:    13:     Microsoft::WRL::ComPtr<ID2D1Factory> d2dFactory;  14:     m_d2dContext->GetFactory(&d2dFactory);  15:    16:     // Create the path geometry.  17:     Microsoft::WRL::ComPtr<ID2D1PathGeometry> pathGeometry;  18:     hr = d2dFactory->CreatePathGeometry(&pathGeometry);  19:    20:     // Write to the path geometry using the geometry sink.  21:    22:     Microsoft::WRL::ComPtr<ID2D1GeometrySink> sink;  23:     if (SUCCEEDED(hr))  24:     {  25:         hr = pathGeometry->Open(&sink);  26:     }  27:    28:     // Get the glyph run outline geometries back from DirectWrite and place them within the  29:     // geometry sink.  30:     if (SUCCEEDED(hr))  31:     {  32:         hr = glyphRun->fontFace->GetGlyphRunOutline(  33:             glyphRun->fontEmSize,  34:             glyphRun->glyphIndices,  35:             glyphRun->glyphAdvances,  36:             glyphRun->glyphOffsets,  37:             glyphRun->glyphCount,  38:             glyphRun->isSideways,  39:             glyphRun->bidiLevel %2,  40:             sink.Get()  41:             );  42:     }  43:    44:     // Close the geometry sink  45:     if (SUCCEEDED(hr))  46:     {  47:         hr = sink.Get()->Close();  48:     }  49:    50:     // Initialize a matrix to translate the origin of the glyph run.  51:     D2D1::Matrix3x2F const matrix = D2D1::Matrix3x2F(  52:         1.0f, 0.0f,  53:         0.0f, 1.0f,  54:         baselineOriginX, baselineOriginY  55:         );  56:    57:     // Create the transformed geometry  58:     Microsoft::WRL::ComPtr<ID2D1TransformedGeometry> transformedGeometry;  59:     if (SUCCEEDED(hr))  60:     {  61:         hr = d2dFactory->CreateTransformedGeometry(  62:             pathGeometry.Get(),  63:             &matrix,  64:             &transformedGeometry  65:             );  66:     }  67:    68:     // Draw the outline of the glyph run  69:     if(SUCCEEDED(hr))  70:     {  71:         m_d2dContext->DrawGeometry(transformedGeometry.Get(),m_brushOutline.Get());  72:         m_d2dContext->FillGeometry(transformedGeometry.Get(),m_brushFill.Get());  73:     }  74:    75:     return hr;  76: }

13-14 透過目前的D2DContext來取得D2DFactory

2013年10月11日星期五

[W8App] Hide / Show cursor

隱藏滑鼠指標

   1: if (Window.Current.CoreWindow.PointerCursor != null) Window.Current.CoreWindow.PointerCursor = null;

顯示滑鼠指標

   1: if (Window.Current.CoreWindow.PointerCursor == null)   2: {   3:     Window.Current.CoreWindow.PointerCursor = new CoreCursor(CoreCursorType.Arrow, 1);   4: }

CoreCursor的id可以自已隨意的指派並不一定是1。

Reference: