Solution:

Psychorisual redundancy is associated with characteristics of the human visual system (UV's). In the HVS, visual information is not perceived equally.

$\rightarrow$ Some information may be more important than other information.

If less data is used to represent less important visual information perception will is called Psychovisual and is not visually imported, it is called Psychovisual redundancy.

Psychovisurial redundancy exists in all images and can be eliminated without hampering the subjective quality of the image.

Improved Grayscale CI GS') coding reduces the quantization but also reduces false contouring.

Steps involved in TGS coding are:

(1) Lower 4 bits of the preceding modified pixel are added to the present pixel.

(2) The new 4 MSEs of the present pixel are taken as the IGS code.

(3) Repeat steps 1 and 2 after moving on to the new pixel.

(9) If MSB is 1111 then add 0000 instead of the 4 LSBS of the previous sum.