Caltech lawyers published market shares data that apparently came from one of the most solid sources - TSR's 2H 2011 report:
There are also few comments on the market and projections for 2012:
"In the 2011 image sensor market in terms of total revenues, Sony secured the largest share of 37.3%. Sony commanded the top share in the CCD area image sensor market and, also in the CMOS area image sensor market, it sold primarily high-end DSLR/mirrorless cameras, high-end camcorders and 8-Mpixel camera phones. It achieved the highest market share in terms of revenue because it sold products of high unit prices. Canon took the second place, followed by Samsung and OmniVision. Canon is increasing its market share in the DSLR application by 43% compared to 2010. Since its unit price zone for DSLR sensors is $65 to 120, Canon is way up on the high level based on the revenue share.
Our projection for 2012 is that Sony will increase its market share and maintain the top position. Its shipments of 1351 sensors for DSCs and camera phones are significantly increasing. Canon plans to ship 10 million DSLRs annually, which is an increase of 33% compared to 2011, and its share of the sensor market in terms of revenue will also increase further, Aptina is also projected to increase shipments of mirror-less camera sensors for Nikon, which will contribute to an increase of its revenue."