diff --git a/src/main/java/cz/it4i/qcmp/DataCompressor.java b/src/main/java/cz/it4i/qcmp/DataCompressor.java
index 966bf6feefd6f279faa270b920ca693c3048839c..078f473daa60bd7500aad880f564105e4794be7a 100644
--- a/src/main/java/cz/it4i/qcmp/DataCompressor.java
+++ b/src/main/java/cz/it4i/qcmp/DataCompressor.java
@@ -5,7 +5,7 @@ import cz.it4i.qcmp.cache.QuantizationCacheManager;
 import cz.it4i.qcmp.cli.CliConstants;
 import cz.it4i.qcmp.cli.CompressionOptionsCLIParser;
 import cz.it4i.qcmp.cli.CustomFunctionBase;
-import cz.it4i.qcmp.cli.functions.EntropyCalculation;
+import cz.it4i.qcmp.cli.functions.CalculateDifference;
 import cz.it4i.qcmp.compression.ImageCompressor;
 import cz.it4i.qcmp.compression.ImageDecompressor;
 import cz.it4i.qcmp.fileformat.FileExtensions;
@@ -93,7 +93,7 @@ public class DataCompressor {
                 //                                           V
                 //CustomFunctionBase customFunction = new MeasurePlaneErrorFunction(parsedCliOptions);
                 // final CustomFunctionBase customFunction = new EntropyCalculation(compressionOptionsCLIParsed);
-                final CustomFunctionBase cf = new EntropyCalculation(compressionOptionsCLIParsed);
+                final CustomFunctionBase cf = new CalculateDifference(compressionOptionsCLIParsed);
                 if (!cf.run()) {
                     System.err.println("Errors occurred during custom function.");
                 }
diff --git a/src/main/java/cz/it4i/qcmp/compression/SQImageCompressor.java b/src/main/java/cz/it4i/qcmp/compression/SQImageCompressor.java
index ae5be444f318c925c6b7d873bbedb7049c4ab850..78f9cbe214b3c8b1bc7c7ddabef02742b0f5c4b9 100644
--- a/src/main/java/cz/it4i/qcmp/compression/SQImageCompressor.java
+++ b/src/main/java/cz/it4i/qcmp/compression/SQImageCompressor.java
@@ -148,10 +148,21 @@ public class SQImageCompressor extends CompressorDecompressorBase implements IIm
         final int[] planeIndices = getPlaneIndicesForCompression(options.getInputDataInfo());
         final long[] planeDataSizes = new long[planeIndices.length];
         int planeCounter = 0;
+
+
+        //        final int[][] preloadedPlaneData;
+        //        try {
+        //            preloadedPlaneData = planeLoader.loadPlanesU16DataTo2dArray(planeIndices);
+        //        } catch (final IOException ex) {
+        //            throw new ImageCompressionException("Unable to preload plane data.", ex);
+        //        }
+
+        //        final int index = 0;
         for (final int planeIndex : planeIndices) {
             stopwatch.restart();
 
             final int[] planeData;
+            //            planeData = preloadedPlaneData[index++];
             try {
                 planeData = planeLoader.loadPlaneData(planeIndex);
             } catch (final IOException ex) {