Color correction method for CMOS camera phone image

Abstract

~ This paper concentrated on color correction of smrrll mega-pixel CMOS image sensor (CIS) tising a new colorimetric characterization method. In the area of mobile camera phone, a small mega-pixel CMOS image sensor is widely used. Ilowever. the RGB signals generated by dijferent CIS ore not eqtial .for the same scene. Therefore, CISs are charocterized h a d on a CIE standard colorimetric ohserver. One method ofderiving U colorimetric characterizution matrix hehwen cumera RGB outpiit sigituls and CIE X Y Z trisfinittlrrs valires is least squares polynomial modeling. Yet, this involves tediotts e.rperiment.s to obtain a CIS transfir matri.r tinder various white balance poirtts for the same CIS. Accordinglj,. the cttrrent paper proposes a new method for obtoining CIS transfer matrices tinder diflirent white balances rising a 3x3 camera tran.@r ma1ri.r under a specific white halance point. As sztch. the proposed methods enables a CIS transfkr matri.r tinder any other white balance to be obtained tising the colorimetric coordinates for the phosphor primaries derived .f>oni a 3x3 littear transfer matrix tinder a certain white halonce point. The e.rperimenta1 restilts confirmed that the /ran$& characteristic of CMOS image sensor after color correction rising the proposed method i.s close to that of ideal CMOS image sensor'. Index Terms CMOS image sensor, colorimetric characterization, color correction, camera phone.