code: public ColorImg clampChannelToUnitRange(int channel){
  		double[] channelData = getData()[channel];
  		for(int i=0; i<channelData.length; i++){
  			channelData[i] = ImagingKitUtils.clamp_0_1(channelData[i]);
  		}
  		return this;
  	}
docs: Clamps all values of the specified channel to unit range [0,1].
  Values less than 0 are set to zero, values greater than 1 are set to 1.
  @param channel one of {@link #channel_r},{@link #channel_g},{@link #channel_b},{@link #channel_a} (0,1,2,3)
  @return this for chaining
  @throws ArrayIndexOutOfBoundsException if the specified channel is not in [0,3]
  or is 3 but the image has no alpha (check using {@link #hasAlpha()}).
  
  @see #clampAllChannelsToUnitRange()
  @see #scaleChannelToUnitRange(int)