YUV 422，YUV 420，YUV 444 [英] YUV 422 , YUV 420 ,YUV 444

问题描述

我有例如4 * 4图像。我想分别提取Y，U和V组件。
如果图像是YUV 422，YUV 420和YUV444，该怎么做。
我有兴趣知道数组的结构如何将Y，U和V存储在422,420和444，
中以便可以访问它。

I have for example 4*4 image. I want to extract the Y,U and V components separately. How to do it if the image is YUV 422 ,YUV 420 and YUV444. I am interested in knowing the structure of array how Y,U and V are stored in 422,420 and 444, so that it can be accessed.

推荐答案

这个网站为您提供了很好的概述不同的YUV格式。还有一个像素结构。

This site gives you a pretty good overview over the different YUV formats. There's also a pixel-structure given.

澄清：这些数字用于确定颜色分量子采样。例如YUV 444 = 4：4：4子采样，意味着三个分量（Y，U和V）中的每一个具有相同的采样率。而4：2：2表示U和V仅以Y的一半速率采样。或者，换句话说，如果深度为1字节，则分别为Y和U和V 1字节的2字节。这意味着Y可以具有更高的动态范围。

For clarification: These numbers are for determination of color component subsampling. For instance YUV 444 = 4:4:4 subsampling, meaning that every of the three components (Y, U and V) has the same sample rate. Whereas 4:2:2 states that U and V are only sampled with half the rate of Y. Or, in other words, 2 Bytes for Y and for U and V 1 Byte respectively, if the depth is 1 Byte. This implies that Y can have a higher dynamic range.

值得注意的是，JPEG标准定义了每种颜色分量的水平和垂直采样因子。人类视觉系统有一个亮度传感器（杆）与色度传感器（视锥细胞）的比例为20：1 。出于这个原因，通常不会对发光度组件进行二次采样，而是 JPEG标准允许对这些内容进行编码。

It is worth noting that JPEG standard defines horizontal and vertical sampling factors for each color component. The human visual system has a 20:1 ratio of the luma sensors (rods) to chroma sensors (cones). For this reason, typically luminosity component is not subsampled, but the JPEG standard does allow such content to be encoded.

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