reduce memory consumption and slice processing speed

src/app/application.js

@@ -608,14 +608,15 @@ dwv.App = function ()
         }
         // flag used by scroll to decide wether to activate or not
         // TODO: supposing multi-slice for zip files, could not be...
-        isMonoSliceData = (data.length === 1 &&
+        var numberOfImages = data.length;
+        isMonoSliceData = (numberOfImages === 1 &&
             firstName.split('.').pop().toLowerCase() !== "zip" &&
             !dwv.utils.endsWith(firstName, "DICOMDIR"));
         // set IO
         loader.setDefaultCharacterSet(defaultCharacterSet);
         loader.onload = function (data) {
             if ( image ) {
-                view.append( data.view );
+                view.append( data.view, numberOfImages);
                 if ( drawController ) {
                     //drawController.appendDrawLayer(image.getNumberOfFrames());
                 }

src/image/image.js

@@ -322,7 +322,7 @@ dwv.image.Image = function(geometry, buffer, numberOfFrames)
      * @param {Image} The slice to append.
      * @return {Number} The number of the inserted slice.
      */
-    this.appendSlice = function (rhs, frame)
+    this.appendSlice = function (rhs, frame, numberOfImages)
     {
         // check input
         if( rhs === null ) {
@@ -361,40 +361,35 @@ dwv.image.Image = function(geometry, buffer, numberOfFrames)
         }
         var sliceSize = mul * size.getSliceSize();
 
-        // create the new buffer
-        var newBuffer = dwv.dicom.getTypedArray(
-            buffer[f].BYTES_PER_ELEMENT * 8,
-            meta.IsSigned ? 1 : 0,
-            sliceSize * (size.getNumberOfSlices() + 1) );
+        // create the new buffer for all slices
+        if(buffer[f].length != sliceSize * numberOfImages){
+           var newBuffer = dwv.dicom.getTypedArray(
+                buffer[f].BYTES_PER_ELEMENT * 8,
+                meta.IsSigned ? 1 : 0,
+                sliceSize * numberOfImages );
+
+            newBuffer.set(buffer[f]);
+            buffer[f] = newBuffer;
+        }
 
         // append slice at new position
         var newSliceNb = geometry.getSliceIndex( rhs.getGeometry().getOrigin() );
-        if( newSliceNb === 0 )
+        if( newSliceNb === size.getNumberOfSlices() )
         {
-            newBuffer.set(rhs.getFrame(f));
-            newBuffer.set(buffer[f], sliceSize);
-        }
-        else if( newSliceNb === size.getNumberOfSlices() )
-        {
-            newBuffer.set(buffer[f]);
-            newBuffer.set(rhs.getFrame(f), size.getNumberOfSlices() * sliceSize);
+            buffer[f].set(rhs.getFrame(f), size.getNumberOfSlices() * sliceSize);
         }
         else
         {
             var offset = newSliceNb * sliceSize;
-            newBuffer.set(buffer[f].subarray(0, offset - 1));
-            newBuffer.set(rhs.getFrame(f), offset);
-            newBuffer.set(buffer[f].subarray(offset), offset + sliceSize);
+            buffer[f].set(buffer[f].subarray(offset, offset + (sliceSize * (size.getNumberOfSlices() - newSliceNb))), offset + sliceSize);
+            buffer[f].set(rhs.getFrame(f), offset);
         }
 
         // update geometry
         geometry.appendOrigin( rhs.getGeometry().getOrigin(), newSliceNb );
         // update rsi
         rsis.splice(newSliceNb, 0, rhs.getRescaleSlopeAndIntercept(0));
 
-        // copy to class variables
-        buffer[f] = newBuffer;
-
 		// insert overlay information of the slice to the image
 		overlays.splice(newSliceNb, 0, rhs.getOverlays()[0]);
 

src/image/view.js

@@ -443,10 +443,10 @@ dwv.image.View = function (image)
      * Append another view to this one.
      * @param {Object} rhs The view to append.
      */
-    this.append = function( rhs )
+    this.append = function( rhs , numberOfImages)
     {
        // append images
-       var newSliceNumber = this.getImage().appendSlice( rhs.getImage() );
+       var newSliceNumber = this.getImage().appendSlice( rhs.getImage(), 0, numberOfImages );
        // update position if a slice was appended before
        if ( newSliceNumber <= this.getCurrentPosition().k ) {
            this.setCurrentPosition(

tests/image/image.test.js

@@ -171,7 +171,7 @@ QUnit.test("Test Image append slice.", function (assert) {
     var sliceGeometry = new dwv.image.Geometry(sliceOrigin, sliceSize, imgSpacing);
     var slice0 = new dwv.image.Image(sliceGeometry, [sliceBuffer]);
     // append slice before
-    image0.appendSlice(slice0);
+    image0.appendSlice(slice0, 0, 4);
     // test its values
     assert.equal( image0.getValue(0, 0, 0), 2, "Value at 0,0,0 (append before)" );
     assert.equal( image0.getValue(3, 3, 0), 2, "Value at 3,3,0 (append before)" );
@@ -194,7 +194,7 @@ QUnit.test("Test Image append slice.", function (assert) {
     var sliceGeometry1 = new dwv.image.Geometry(sliceOrigin1, sliceSize, imgSpacing);
     var slice1 = new dwv.image.Image(sliceGeometry1, [sliceBuffer]);
     // append slice before
-    image1.appendSlice(slice1);
+    image1.appendSlice(slice1, 0, 4);
     // test its values
     assert.equal( image1.getValue(0, 0, 0), 0, "Value at 0,0,0 (append after)" );
     assert.equal( image1.getValue(3, 3, 0), 0, "Value at 3,3,0 (append after)" );
@@ -217,7 +217,7 @@ QUnit.test("Test Image append slice.", function (assert) {
     var sliceGeometry2 = new dwv.image.Geometry(sliceOrigin2, sliceSize, imgSpacing);
     var slice2 = new dwv.image.Image(sliceGeometry2, [sliceBuffer]);
     // append slice before
-    image2.appendSlice(slice2);
+    image2.appendSlice(slice2, 0, 4);
     // test its values
     assert.equal( image2.getValue(0, 0, 0), 0, "Value at 0,0,0 (append between)" );
     assert.equal( image2.getValue(3, 3, 0), 0, "Value at 3,3,0 (append between)" );