. BandedSampleModel . createDataBuffer computes the size & allocates DataBuffer as
     int size = scanlineStride * height;
     dataBuffer = new DataBuffer<Type>(size, numBanks);

. This holds good if the BandedSampleModel contains mulitple banks.
. If the BandedSampleModel contains only one bank to store all the bands, the computed size will not suffice and cause ArrayIndexOutOfBounds exception.

. For Example:
  Consider a 3 x 3 BandedSampleModel with 1 Bank and 3 Bands
  The DataBuffer would be- RRRRRRRRRGGGGGGGGGBBBBBBBBB
  The size required is 27 DataBuffer array elements.
  The size as computed in existing logic would be (scanline stride) 3 * 3 (height) = 9 array elements.