code: public double getValue(int channel, int x, int y, int boundaryMode) {
  		return delegate.getValue(channel, x, y, boundaryMode);
  	}
docs: See {@link ColorImg#getValue(int, int, int, int)}.
  <p>
  Please Notice that when using {@link #CHANNEL_POWER},
  this will not calculate the power in case it is not up to date.
  Use {@link #recomputePowerChannel()} to make sure this method yields reasonable results.
  @param channel one of {@link #CHANNEL_REAL},{@link #CHANNEL_IMAG},{@link #CHANNEL_POWER}(0,1,2)
  @param x coordinate
  @param y coordinate
  @param boundaryMode one of the boundary modes e.g. {@link ColorImg#boundary_mode_repeat_image}
  @return value at specified position or a value depending on the
  boundary mode for out of bounds positions.