added overlay option to flake

flake.nix

@@ -15,6 +15,7 @@
     pkgs = nixpkgs.legacyPackages.${system};
 
     name = "scannedImageExtractor";
+    version = "0.2.7-beta";
   in {
     packages.${system} = {
       default = let
@@ -35,14 +36,14 @@
 
           nativeBuildInputs = with pkgs; [
             cmake
-            opencv2
+            opencv3
             liblbfgs
             qt5.full
             libsForQt5.qt5.wrapQtAppsHook
           ];
 
           configurePhase = ''
-            cmake scannerExtract -DCMAKE_BUILD_TYPE=release -DOPENCV2=1
+            cmake scannerExtract -DCMAKE_BUILD_TYPE=release
           '';
 
           buildPhase = ''
@@ -57,7 +58,7 @@
 
             # Install icons
             for dimension in 128 256; do
-              install -m 444 $src/scannerExtract/ico/${name}''${dimension}x''${dimension}.png -D $out/share/icons/''${dimension}x''${dimension}/apps/${name}.png
+              install -m 444 $src/scannerExtract/ico/${name}''${dimension}x''${dimension}.png -D $out/share/icons/hicolor/''${dimension}x''${dimension}/apps/${name}.png
             done
           '';
         };
@@ -72,7 +73,7 @@
           dontBuild = true;
 
           installPhase = ''
-            install -m 555 $src -D $out/${name}.AppImage
+            install -m 555 $src -D $out/${name}-v${version}.AppImage
           '';
         };
     };
@@ -80,19 +81,25 @@
     apps.${system} = {
       appImage = {
         program = "${pkgs.writeShellScript "scannedImageExtractor" ''
-          ${pkgs.appimage-run}/bin/appimage-run ${self.packages.${system}.appImage}/${name}.AppImage
+          ${pkgs.appimage-run}/bin/appimage-run ${self.packages.${system}.appImage}/${name}-v${version}.AppImage
         ''}";
         type = "app";
       };
     };
 
-    devShells = {
+    overlays = {
+      default = final: prev: {
+        scanned-image-extractor = self.packages.${system}.default;
+      };
+    };
+
+    devShells.${system} = {
       default = pkgs.mkShellNoCC {
         packages = with pkgs; [
           cmake
-          opencv2
+          opencv3
           liblbfgs
-          gt5.full
+          qt5.full
 
           appimage-run
         ];

scannerExtract/preloadsource.cpp

@@ -194,14 +194,20 @@ void PreloadSource::getSumOfRectangleSampling(const QVector<cv::Point2f> pts,
     sumValues = 0;
     numPixels = 0;
 
-    IplImage tmp = image;
+    IplImage tmp = cvIplImage(image);
     assert(image.type() == CV_8U);
 
     for (int i=0; i<4; i++)
     {
 
         CvLineIterator iterator;
-        const int count = cvInitLineIterator( &tmp, pts[i], pts[(i+1)%4], &iterator, 4);
+        const int count = cvInitLineIterator(
+            &tmp,
+            cvPoint(cvRound(pts[i].x), cvRound(pts[i].y)),
+            cvPoint(cvRound(pts[(i + 1) % 4].x), cvRound(pts[(i + 1) % 4].y)),
+            &iterator,
+            4
+        );
 
         for( int j = 0; j < count; j++ ){
             sumValues += iterator.ptr[0];