LMS-2502 image transformations: mor robust transformation factories

SVN: 22932

screening/source/java/ch/systemsx/cisd/openbis/dss/etl/dto/api/v1/transformations/AutoRescaleIntensityImageTransformerFactory.java

@@ -51,6 +51,10 @@ public class AutoRescaleIntensityImageTransformerFactory implements IImageTransf
             {
                 public BufferedImage transform(BufferedImage image)
                 {
+                    if (IntensityRescaling.isNotGrayscale(image))
+                    {
+                        return image;
+                    }
                     Levels levels = IntensityRescaling.computeLevels(image, threshold);
                     return IntensityRescaling.rescaleIntensityLevelTo8Bits(image, levels);
                 }

screening/source/java/ch/systemsx/cisd/openbis/dss/etl/dto/api/v1/transformations/BitShiftingImageTransformerFactory.java

@@ -33,6 +33,10 @@ final class BitShiftingImageTransformerFactory implements IImageTransformerFacto
             {
                 public BufferedImage transform(BufferedImage image)
                 {
+                    if (IntensityRescaling.isNotGrayscale(image))
+                    {
+                        return image;
+                    }
                     return IntensityRescaling.rescaleIntensityBitShiftTo8Bits(image, shiftBits);
                 }
             };

screening/source/java/ch/systemsx/cisd/openbis/dss/etl/dto/api/v1/transformations/IntensityRangeImageTransformerFactory.java

@@ -53,6 +53,10 @@ public class IntensityRangeImageTransformerFactory implements IImageTransformerF
             {
                 public BufferedImage transform(BufferedImage image)
                 {
+                    if (IntensityRescaling.isNotGrayscale(image))
+                    {
+                        return image;
+                    }
                     Levels levels = new Levels(blackPointIntensity, whitePointIntensity);
                     return IntensityRescaling.rescaleIntensityLevelTo8Bits(image, levels);
                 }