The method ImageUtil.flattenTransparentImageForOpaqueFormat(BufferedImage, OutputFormat) fails for the following cenario
1) input is png and output jpg
2) input is gif and output jpg

the exceptions are not the same

1) java.lang.ClassCastException: java.awt.image.ComponentColorModel cannot be cast to java.awt.image.DirectColorModel

2) java.lang.ArrayIndexOutOfBoundsException: 1
at java.awt.image.PixelInterleavedSampleModel.createSubsetSampleModel(PixelInterleavedSampleModel.java:142)
at sun.awt.image.ByteInterleavedRaster.createWritableChild(ByteInterleavedRaster.java:1279)
at info.magnolia.imaging.util.ImageUtil.flattenTransparentImageForOpaqueFormat(ImageUtil.java:3