In the Human eye there are two
types of image receptor cells cones and rods.
Rods are helpful for seeing the image in low
light or in the dark whereas the cones work for
seeing the image in different colours. Both the
receptors cells are found in retina of human
eye. They contain three colour pigments Red
(Large Bandwidth), Green (Medium
Bandwidth) and Blue (Small Bandwidth) by
which we are trichromats (tri=3
chromats=colour) and able to see any object
in the world because of all objects are
viewable by these colour hues. Mostly the
colour blindness is the genetic mutation and
not to be cured. It can also get place when
there is a problem related to pigments in
certain nerve cells (cone) of the eye or when
there would be a trauma in mind or the
chemical accident by which those receptor
cells got affect. In the Human vision there are
different stages which describe what type of
colour vision deficiency the people have.
Monochromacy (1%): Total colour blinded
Dichromacy (10%): Partial colour blinded (i)
red-green colour blindness (ii) blue-yellow
colour blindness. Trichromacy: Normal
colour vision. The Dichromacy, this type of
colour blindness mostly people have. So
correcting it,a new filter is developed in the
image processing on the basis of Ishihara
colour test. It works successfully as per tested
it many time. In this filter adjusting, contrast
stretching and inverting function are used for
providing better result and it does. By
applying this new filter the normal and as well
colour vision deficient people easily recognise
the objects whether they are of any of shape,
number or alphabets.