Information Technology Reference
In-Depth Information
Fig. 1
Spatio-temporal resolution of current video formats
high spatial resolution, large dynamic range, accurate color reproduction, and high
temporal resolution. For example, digital cinema[1][2] and Super Hi-Vision TV
(SHV)[3][4] offer digital images with high-resolution. As encoders for such high-
resolution video formats, H.264 codec for SHV [5] and JPEG2000 codec for digital
cinema [6], have been developed. Displays suitable for high-dynamic-range (HDR)
images are being developed [7] [8]. JPEG-XR, an HDR image encoding scheme,
has been approved as international standard/recommendation [9]. Scalable video
coding using tone mapping is one of the approaches being studied for HDR video
encoding [10] [11]. Advanced efforts to achieve accurate color reproduction are be-
ing made within the Natural Vision Project [12]. H.264/AVC Professional profile
supports 4:4:4 color format [13].
In order to create more realistic representations, it is becoming more obvious
that the frame-rate is the next factor that will have to be addressed, as shown in
Figure 1. The current frame-rate (60 [frames/sec] or [fields/sec]) was simply se-
lected as the lowest rate that well suppressed flickering. Unfortunately, suppress-
ing flicker is not directly connected to the representation of smooth movement. We
note that Spillmann found that the gangliocyte of the retina emits up to 300 - 400
[pulses/sec] [14]. Thus, we estimate that the human visual system can perceive light
pulses that are 1/150 - 1/200 [sec] long, i.e. the maximum detectable frame-rate is
150 - 200 [frames/sec] from the biochemical viewpoint.
Over the past decade the video acquisition rate has increased drastically. For ex-
ample, a high-speed HDTV camera that can shoot at 300 [frames/sec] has been
developed [15]. Another development is the high speed imaging system that uses
