Comparison of YIQ and YCbCr

[Mihai Cartoaje]

I designed a lossless YIQ color transform that requires 2 or 5
multiplications. It is like this:

R -= B
B += R >> 1
B -= G
G += B >> 1
G += round(- (0.5 - Kb - Kr) * B + (Kr - Kb) * R / 2.0)
B -= round(((1 - cos(45 - theta)) / sin(45 - theta)) * R)
R += round(sin(45 - theta) * B)
B -= round((((1 - cos(45 - theta)) / sin(45 - theta)) - sin(45 -
theta) * cos(45 - theta) / (4 - sin(45 - theta) * sin(45 - theta))) *
R)
Y = G
I = R
Q = B

Patent pending. The attached files are:

Original of the Majandra image
YCbCr 4:1:1
YCbCr 2:1:1
YIQ 4:2:1 with a rotation of 33 degrees
YIQ 4:2:1 with a rotation of 45 degrees

The ratios are the quantizers.

The image transform used for these images is a novel transform
described on my website:
http://www.geocities.com/repstsb/index.html

[Mihai Cartoaje]

The second and third images.

[Mihai Cartoaje]

The fourth and fifth images.