JVC Professional APRIL 2007 NAB-2007 The ProHD Report
Copyright 2007 JVC Professional Products Company All rights reserved Page 37 of 43
Comparing with ProHD, the total pixels/sec is the same, but DVCPRO-HD
luminance falls short of the 55 million luminance pixel/sec of the ATSC, while the
chrominance pixel/sec at 41.5 million is significantly higher than the 28 million
ATSC, being limited by that “28 million pipe”.
And, looking at the newly announced Panasonic HPX500 P2HD camcorder
(DVCPRO-HD recording) stated to have a sub-HD-resolution 620,000-pixel 3CCD
native imager (presumed then to be 960 pixels horizontally and, further assuming
16:9 square pixels, 540 active pixels vertically), results in each of luminance and
chrominance at 31 million pixels/sec (from a native imager reference point). The
HPX500 camera front end does apply 2-dimensional pixel offset and sophisticated
processing, thereby significantly increasing the effective capture resolution above the
native 620,000 pixels CCDs.
A Sony XDCAM HD Camcorder, delivering to the TV station through the PD
optical disc format 1440x1080i60 4:2:0, also requires pixel conversions due to the
limited 1440/720 to be scaled to 1920/960:
1440x1080i60 x 1.5 (x 70%) = 49 million pixels/sec (after Kell/I reduced to 70%)
Luminance 1440x1080i60 = 33 million (after Kell/I reduction)
Chrominance = 16 million (after Kell/I reduction)
Format
Total
Pixels/Second
Luminance &
Chrominance
Total PERCEIVED
Pixels/Second
(Interlaced reduced to
70% by Kell/I factor)
Pixels/Second
PERCEIVED
Luminance only
(after Kell/I factor)
ATSC 720p (REF) 83 million No reduction
Progressive
55 million
(no reduction)
ATSC 1080i (REF) 93 million 65 million 44 million
JVC ProHD 83 million No reduction
Progressive
55 million
(no reduction)
Panasonic
DVCPRO-HD (720p) 83 million No reduction
Progressive
41.5 million
(no reduction)
Sony XDCAM HD 70 million 49 million 33 million
Fig. 20. This table recaps the analysis that the Kell/Interlaced factor
reduces the viewer’s perceived resolution by about 70% average, while
progressive material is nearly unaffected. JVC’s ProHD is the only
format matching the ATSC reference. Effective maximum pixels per
second is just one of several parameters indicative of the quality of the
home viewer’s perceived HD video quality. Size of camcorder imager,
compression type and efficiency are other important parameters
affecting the viewer’s HD experience, as are shooting conditions.