Although over 50 years old , the standard television signal is still one of the most common way to transmit an image. Figure 8.3 shows how the television signal appears on an oscilloscope. This is called composite video, meaning that there are vertical and horizontal synchronization (sync) pulses mixed with the actual picture information.
These pulses are used in the television receiver to synchronize the vertical and horizontal deflection circuits to match the video being displayed. Each second of standard video contains 30 complete images, commonly called frames , A video engineer would say that each frame contains 525 lines, the television jargon for what programmers call rows. This number is a little deceptive because only 480 to 486 of

盡管已經(jīng)擁有50年的歷史了,電視信號(hào)依然是常用的傳遞信息的途徑之一。圖 8.3演示了電視信號(hào)如何出現(xiàn)在一個(gè)示波器上。這叫做合成信號(hào),意謂有垂直的方向和水平的方向的合成(同步)和真實(shí)的圖片數(shù)據(jù)混合的脈沖信號(hào)。
這些脈沖被電視接收器同垂直與水平線以及其他歪斜線路配和成信號(hào)并被電視顯示出來(lái)。標(biāo)準(zhǔn)的信號(hào)每秒包含30個(gè)完整的圖像,一般被做成了體格,電視工程師會(huì)把每個(gè)體格編制成包含525條行（電視專門術(shù)語(yǔ)）。因?yàn)樵谶@些線中的只有80到486條包含了電視信