Index: /trunk/src/org/openstreetmap/josm/gui/dialogs/layer/LayerVisibilityAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/dialogs/layer/LayerVisibilityAction.java	(revision 14386)
+++ /trunk/src/org/openstreetmap/josm/gui/dialogs/layer/LayerVisibilityAction.java	(revision 14387)
@@ -3,4 +3,5 @@
 
 import static org.openstreetmap.josm.tools.I18n.tr;
+import static org.openstreetmap.josm.tools.I18n.trc;
 
 import java.awt.BorderLayout;
@@ -15,5 +16,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Dictionary;
 import java.util.HashMap;
+import java.util.Hashtable;
 import java.util.List;
 import java.util.function.Supplier;
@@ -248,4 +251,16 @@
 
             slider.addChangeListener(e -> onStateChanged());
+
+            //final NumberFormat format = DecimalFormat.getInstance();
+            //setLabels(format.format(minValue), format.format((minValue + maxValue) / 2), format.format(maxValue));
+        }
+
+        protected void setLabels(String labelMinimum, String labelMiddle, String labelMaximum) {
+            final Dictionary<Integer, JLabel> labels = new Hashtable<>();
+            labels.put(slider.getMinimum(), new JLabel(labelMinimum));
+            labels.put((slider.getMaximum() + slider.getMinimum()) / 2, new JLabel(labelMiddle));
+            labels.put(slider.getMaximum(), new JLabel(labelMaximum));
+            slider.setLabelTable(labels);
+            slider.setPaintLabels(true);
         }
 
@@ -334,8 +349,9 @@
     class OpacitySlider extends AbstractFilterSlider<Layer> {
         /**
-         * Creaate a new {@link OpacitySlider}.
+         * Create a new {@link OpacitySlider}.
          */
         OpacitySlider() {
             super(0, 1, Layer.class);
+            setLabels("0%", "50%", "100%");
             slider.setToolTipText(tr("Adjust opacity of the layer."));
         }
@@ -410,4 +426,5 @@
         GammaFilterSlider() {
             super(-1, 1, ImageryLayer.class);
+            setLabels("0", "1", "∞");
             slider.setToolTipText(tr("Adjust gamma value of the layer."));
         }
@@ -469,4 +486,5 @@
         SharpnessSlider() {
             super(0, MAX_SHARPNESS_FACTOR, ImageryLayer.class);
+            setLabels(trc("image sharpness", "blurred"), trc("image sharpness", "normal"), trc("image sharpness", "sharp"));
             slider.setToolTipText(tr("Adjust sharpness/blur value of the layer."));
         }
@@ -506,4 +524,5 @@
         ColorfulnessSlider() {
             super(0, MAX_COLORFUL_FACTOR, ImageryLayer.class);
+            setLabels(trc("image colorfulness", "less"), trc("image colorfulness", "normal"), trc("image colorfulness", "more"));
             slider.setToolTipText(tr("Adjust colorfulness of the layer."));
         }