Canon Inc unveiled two astonishing features of its in-house designed "Digic 4" image processing LSI for digital cameras to Nikkei Electronics at a new products presentation Sept 17, 2008.
(1) The Digic 4 encodes and decodes HDTV (1080/30p) video signals according to the H.264 standard.
(2) "B-frame" encoding, a technology that predicts and interpolates frames by referring forward and backward, is not used in the codec process.
Although we could not confirm the details, including how far the Digic 4's circuits are specialized in encoding and decoding, Canon said no special companion chips are used.
The company plans to mount the Digic 4 processors, with almost the same specifications, in all of its digital cameras from now on. The Digic 4 will outperform the specifications of its lower priced cameras with poor video capability. But the company said it is a measures to boost a mass-production effect. Canon's will use nearly 30 million units of the Digic processors per year.
Canon did not reveal the generation of the process technology used for the Digic 4. As the chip area of the die on a semiconductor package measuring about 1 x 1cm was not very large, Canon appears to have used a quite advanced generation process.
The available functions greatly differ among the types of cameras, even if the same type of the Digic 4 is embedded. The Digic 4 is already slated for use in the following models:
- 5D Mark II and 50D in the EOS series
- I3000 IS and 920 IS in the XY Digital series
- G10, SX1 IS and SX10 IS in the PowerShot series
Canon did not use the B-flame encoding because it aimed at keeping the power consumption and circuit scale low and small as well as increasing user convenience.
"We aimed to make it possible to enjoy a fine photo by picking out a frame from a paused HDTV video," Canon said. "As evidenced by the fact that many users prefer shooting video in the RAW format, which does not compress video as much as the other formats, users are seeking high quality of video (rather than long-hour recording capability)."
As the Digic 4 does not use such a powerful encoding tool as B-flame, its encoding speed (bit rate) is relatively high. Canon, however, lowered the bit rate by limiting frame speeds to 30fps instead of 60fps, for example. Specifically, its encoding speed is about 6 Mbytes per second.
Canon introduced the Digic 4's capabilities as well at the press conference. What attracted interest most was its ability to perform highly effective face recognition and motion tracking at the same time. In the demonstration, detected faces and motions were indicated in yellow and blue frames, respectively (movie).
The face recognition capability simultaneously captures up to 35 faces and automatically sets focus and other shooting conditions for nine faces that it determines to be the most important.
The motion tracking is now able to automatically set an ISO sensitivity and a shutter speed in accordance with the results of face recognition. The ability to detect the subject's motion is about 10 times higher than that of the Digic 3, according to Canon.