Information about TV Signals
Over the Air
Satellite
Cable
Analog |
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Digital | Antenna | |
Signal | Signal | at Your |
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| Home |
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| Satellites |
Satellite TV |
| Satellite |
Company |
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| Receiver | |
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| Satellite | at Your |
| Dish | Home |
| at Your |
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| Home |
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| Telephone Line |
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Cable TV |
| For Direct Connection |
Company |
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| to Your TV or to a | |
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| Cable Box,VCR, or |
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| Satellite Receiver |
| Cable TV Signal (Analog) |
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Your High-definition-ready Set
Resolution information
Image resolutions are commonly referred to by a num- ber followed by a letter: 480i, 480p, 720p and 1080i. The number in each format refers to the number of lines of resolution, so for example both 480i and 480p offer 480 lines of resolution. The "i" or "p" refers to whether the signal is displayed using respectively interlaced or progressive scan. Interlaced scan breaks each frame of video into 2 fields, one made up of even lines and one made up of odd lines. The image is reproduced by draw- ing all odd lines first (1,3,5,…479) than all the even ones (2,4,6,….,480). Progressive scan, on the other hand
reproduces an image by drawing all lines in succession 1,2,3,4,….480).
Interlaced Scan |
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| Progressive Scan | |||||
Odd lines | Even Lines |
| Lines in succession | |||||
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