converting an image to cmyk bitmap increases its initial size. it's happening in corel x4 only.... is this a bug?
It is not only in X4. CMYK will always be bigger than RGB encoding. You get a wider range of colour using CMYK. CMYK is 32 bit where RGB only goes up to 24 bit, resulting in a bigger file.
i was not referring at the file size. i was referring at the bitmap dimensions in mm.