视频术语（Video terminology）.docVIP

视频术语（Video terminology） Contrast is the ratio of black to white in the picture, that is, the gradation from black to white. The greater the ratio, the more gradual gradation from black to white, so that the more colorful the color is. There are 2 kinds of contrast test method in the projector industry, one is full on / off contrast test, the test output projector all white screen and black screen brightness ratio. The other one is ANSI contrast, it adopts ANSI Standard Test Method for testing contrast, ANSI contrast test method with 16 black and white color, the ratio between the average value of 8 white and 8 black brightness luminance is ANSI contrast. The contrast values obtained by the two methods are very different, which is also an important reason for the difference in nominal contrast of different manufacturers products. Contrast effects on visual effects are critical. In general, the larger the contrast, the clearer and sharper the image is, the brighter the color is, and the contrast is small, which makes the whole picture look gray. High contrast is very helpful for image clarity, detail performance and gray level representation. In some black-and-white contrast text display, CAD display and black and white photo display, etc., high contrast products in black and white contrast, clarity, integrity and other advantages. Comparatively speaking, the influence of high contrast on image is not obvious in color hierarchy. In contrast to the dynamic video display effect is larger, due to the dynamic image in the dark conversion faster, the higher the contrast, the human eye is easy to distinguish this conversion process. Dynamic contrast Dynamic contrast, refers to the contrast value of liquid crystal display in certain circumstances is measured, such as one by one test screen of every region, the maximum contrast region contrast value, as compared to the product parameters. Different measurement methods for dynamic contrast may also be different, but its essenc