  Steganography is one of the methods used for secret communication.
Steganography attempts to hide the existence of the information. The object
used to hide the secret information is called as cover object. Images are the
most popular cover objects used for steganography. Different techniques have to
be used for color image steganography and grey scale image steganography since
they are stored in different ways. Color image are normally stored with 24 bit
depth and grey scale images are stored with 8 bit depth. Color images can hold
large amount of secret information since they have three color components.
Different color spaces namely RGB (Red Green Blue), HSV (Hue, Saturation,
Value), YUV, YIQ, YCbCr (Luminance, Chrominance) etc. are used to represent
color images. Color image steganography can be done in any color space domain.
In this paper color image steganography in RGB and YCbCr domain are compared.
The secret information considered is grey scale image. Since RGB is the common
method of representation, hiding secret information in this format is not
secure.
