why this error when i use the separate channel from RGB image in integer wavelet transform?

hello, please help me

when i use the integer wavelet transform on RGB image everything is ok there is no problem, but when i separate the image into its layers R, G, and B and applying the integer wavelet transform in single layer R, G, or B the program return errors _ _ "Integers can only be combined with integers of the same class, or scalar double."__ .this error will gone if i convert the data type of layer from uint8 class to double class but i want to keep the integer type. please help me to solve this problem?

imdata = imread('1.tif');

liftscheme = liftwave('haar','int2int');

RedChannel= imdata (:, :, 1);

GreenChannel = imdata (:, :, 2);

BlueChannel = imdata (:, :, 3);

[LLC, LHC, HLC, HHC] = lwt2(RedChannel, liftscheme);

[KSSV]

After the result, you have a option to convert double to uint8..

[Ahmed almansory]

Thanks