- Domeniu:
- Number of terms: 20560
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- Company Profile:
Tektronix provides test and measurement instruments, solutions and services for the computer, semiconductor, military/aerospace, consumer electronics and education industries worldwide.
A joint venture of Bosch Fernseh and Philips established to sell television production equipment. BTS offers the first multi-standard HDTV camera.
Industry:Entertainment
One of the color difference signals used in the NTSC system, obtained by subtracting luminance from the blue camera signal. This is the signal that drives the horizontal axis of a vectorscope. The human visual system has much less acuity for spatial variation of color than for brightness.
Rather than conveying RGB, it is advantageous to convey luma in one channel, and color information that has had luma removed in the two other channels. In an analog system, the two color channels can have less bandwidth, typically one-third that of luma. In a digital system each of the two color channels can have considerably less data rate (or data capacity) than luma. Green dominates the luma channel: about 59% of the luma signal comprises green information. Therefore, it is sensible, and advantageous for signal-to-noise reasons, to base the two color channels on blue and red. The simplest way to remove luma from each of these is to subtract it to form the difference between a primary color and luma. Hence, the basic video color-difference pair is (B-Y), (R-Y) (pronounced “B minus Y, R minus Y”). The (B-Y) signal reaches its extreme values at blue (R = 0, G = 0, B = 1; Y = 0.114; B-Y = +0.886) and at yellow (R = 1, G = 1, B = 0; Y = 0.886; B-Y = –0.886). Similarly, the extreme of (R-Y), + –0.701, occur at red and cyan. These are inconvenient values for both digital and analog systems. The color spaces YPbPr, YCbCr, Photo YCC, and YUV are simply scaled versions of (Y, B-Y, R-Y) that place the extreme of the color difference channels at more convenient values.
Industry:Entertainment
Specifies the standard for weighted and unweighted noise measurements. The weighted standard specifies the weighting filter and quasi-peak detector. The unweighted standard specifies a 22 Hz to 22 kHz bandwidth limiting filter and RMS detector.
Industry:Entertainment
Method for the Subjective Assessment of the Quality of Television Pictures. CCIR-500 is a detailed review of the recommendations for conducting subjective analysis of image quality. The problems of defining perceived image quality are reviewed, and the evaluation procedures for interval scaling, ordinal scaling, and ratio scaling are described – along with the applications for which each is best employed.
Industry:Entertainment
