PCM Encoded NTSC Color Television Subjective Tests

Metadata

Publisher: SMPTE
Doc Type: Journal Article
Article Type: research-article
Abstract: Digital television may effectively serve as the means to store, process and control color television signals within a broadcast plant. Pulse code modulation (PCM) involves the periodic amplitude sampling of a video signal and the conversion of each sample into a binary number of n bits. The PCM signal bit stream can be in n parallel channels or be time multiplexed into a single channel. In either case the total bit rate equals n times the encoding rate. We desire to minimize the bit rate in order to save circuit elements and bandwidth, consistent of course with acceptable picture quality. A series of subjective tests was conducted to determine the importance of various parameters when PCM encoding an NTSC, 525-line, 60-field, composite television signal. Among these parameters are: (1) the number of amplitude levels being sampled that, in turn, define the n-bit digital word; (2) the encoding rate, both locked and unlocked with respect to the 3.58-MHz color subcarrier; and (3) the role of dither consisting of coherent square waves and weighted noise. The test setup consisted of a color film camera, encoding rate generators, dither generators, A/D and D/A converters, color and monochrome monitors. A test panel of experienced viewers examined the pictures in a controlled environment and rated each picture on a stepped acceptance scale. We concluded that NTSC television pictures that had been encoded with 6 or more bits per codeword suffered negligible impairment. The encode rate should be phase coherent with the color subcarrier in order to avoid beats in the picture. Dither signals did not make any improvement in picture quality except to mask contours during 4- or 5-bit encoding.
Publication Date: 1973-08-01
DOI: 10.5594/J13463
Link: https://doi.org/10.5594/J13463
Author(s): A. A. Goldberg

Source Data (JSON)

Full registry record with provenance metadata. Open directly: /api/doc/10.5594-J13463.json

Reference this Doc

Plain text (ISO 690 compliant)

Preview:

A. A. Goldberg; PCM Encoded NTSC Color Television Subjective Tests, Journal of the SMPTE ( Volume: 82, Issue: 8, August 1973); SMPTE, 1973. Available at https://doi.org/10.5594/J13463

Snippet:

A. A. Goldberg; PCM Encoded NTSC Color Television Subjective Tests, Journal of the SMPTE ( Volume: 82, Issue: 8, August 1973); SMPTE, 1973. Available at https://doi.org/10.5594/J13463

HTML (ISO 690 compliant)

Preview:

A. A. Goldberg; PCM Encoded NTSC Color Television Subjective Tests, Journal of the SMPTE ( Volume: 82, Issue: 8, August 1973); SMPTE, 1973. Available at https://doi.org/10.5594/J13463

Snippet:

<span class="citation">A. A. Goldberg; <cite>PCM Encoded NTSC Color Television Subjective Tests</cite>, Journal of the SMPTE ( Volume: 82, Issue: 8, August 1973); SMPTE, 1973. Available at <a href="https://doi.org/10.5594/J13463" target="_blank" rel="noopener">https://doi.org/10.5594/J13463</a></span>

SMPTE's HTML Pub

Preview:

A. A. Goldberg; PCM Encoded NTSC Color Television Subjective Tests, Journal of the SMPTE ( Volume: 82, Issue: 8, August 1973); SMPTE, 1973
doi: 10.5594/J13463
url: https://doi.org/10.5594/J13463

Snippet:

<li>
A. A. Goldberg; <cite id="bib-10-5594-j13463">PCM Encoded NTSC Color Television Subjective Tests</cite>, Journal of the SMPTE ( Volume: 82, Issue: 8, August 1973); SMPTE, 1973
<span class="doi">10.5594/J13463</span>
</li>