Fix/release all mat (openpnp#1007)

* Made sure all Mat are released

* removed a bit too much, reverted that change but made sure the Mat is
released if not returned.

* Typo

Co-authored-by: Johannes Formann <johannes@formann.de>

src/main/java/org/openpnp/vision/pipeline/stages/MaskHsv.java

@@ -391,6 +391,12 @@ public Result process(CvPipeline pipeline) throws Exception {
                 endIdx = -1;
                 startIdx = -1;
             }
+            workingMat.release();
+            mv.release();
+            hist.release();
+            ranges.release();
+            channels.release();
+            histSize.release();
             setValueMax( endIdx );
             Logger.trace( "valueMax = " + valueMax );
             setValueMin( startIdx );
@@ -420,6 +426,7 @@ public Result process(CvPipeline pipeline) throws Exception {
             Core.inRange(mat, min, max, mask2);
 
             Core.bitwise_or(mask, mask2, mask);
+            mask2.release();
         }
 
         //The mask is normally inverted because it is used to copy the unmasked portions of the
@@ -430,12 +437,12 @@ public Result process(CvPipeline pipeline) throws Exception {
 
         double fractionActuallyMasked = 1.0 - Core.countNonZero(mask) / (double) ( mat.rows() * mat.cols() ) ;
         Logger.trace( "Fraction actually masked = " + fractionActuallyMasked );
-
         if (binaryMask) {
+            masked.release();
             return new Result(mask);
-        } 
-        else {
+        } else {
             mat.copyTo(masked, mask);
+            mask.release();
             return new Result(masked);
         }
     }

src/main/java/org/openpnp/vision/pipeline/stages/Normalize.java

@@ -26,6 +26,7 @@ private void filter(Mat src){
 	    }
           }
 	  src.put(0, 0, pixel);
+	  dst.release();
 	}
 
     @Override