|
The unfair advantage Once the lens has done its job of producing an image with as much clarity and accuracy as possible, the camcorder's processor must collect the resulting raw data from the sensor and prepare it for storage to the
camcorder's storage media. Canon's background and experience in the manufacture of Large Scale Integrated circuits (LSIs) has allowed it to develop its own, now renowned, image processor – DIGIC DV (DIGital Image Core - Digital Video). This
gives Canon a unique advantage over competitors who must rely on generic third party circuitry. As well as having remarkable image rendering capacity, DIGIC DV also makes an impact in
two very important ways. Frame Rate The power of DIGIC DV has allowed the maximum still frame rate in continuous shooting mode to be raised from an industry standard of 13 VGA (640x480 pixels) images at 2 frames per second to a much improved 30 images at 3
fps. When resolution is pushed to the SXGA standard (1280x960 pixels) a DIGIC DV equipped camcorder will be able to manage 10 images at a rate of 2fps, while most others can only cope with 4 frames using this resolution and frame rate. This results from
the faster processing power of the DIGIC DV - which needs to make less use of buffer memory - and the improved memory card access. Dual processing streams
While movies will be most often watched on a TV set, still photos will probably be viewed on a PC and/or output to a photo printer. As such, the two different destinations ideally require different processing to optimise colour space for the method they
will be viewed. The power of DIGIC DV allows these dual processing streams. Video footage has a maximum of 220 possible gradations, or steps from white to black, whereas the standard for digital stills is JPEG, with 250 gradations. In conventional camcorders with 'digital still' capability, the
'still' image is simply a sample of the video image that is 'stretched' to fit the JPEG format. This stretching process degrades the image, which is why digital images lifted from video footage are usually of such low quality. The dual processing stream inside DIGIC DV avoids this compromise, delivering true JPEG digital still quality and making workflow in still-image programs and desktop printing much more straightforward and reliable. back
|
