#Ffmpeg map filter tv

In other words, the U and V signals tell the television to shift the color of a certain spot without altering its brightness. The UV representation of chrominance was chosen over straight R and B signals because U and V are color difference signals. The luma component already existed as the black and white signal they added the UV signal to this as a solution.

#Ffmpeg map filter tv

They needed a signal transmission method that was compatible with black-and-white (B&W) TV while being able to add color. Y′UV was invented when engineers wanted color television in a black-and-white infrastructure. The YDbDr color model, used in the analog SECAM and PAL-N television broadcasting systems, is also related. The Y′IQ color model used in the analog NTSC television broadcasting system also broadly follows the same principles as YUV, although in a more complex way. On these color models C B/P B and C R/P R are deviations from grey on blue–yellow and red–cyan axes, whereas on YUV U and V are blue–luminance and red–luminance differences respectively. Likewise, the YPbPr color model used in analog component video is sometimes called Y′UV. But the same designation is sometimes applied to YCbCr, used for digital encoding of color information suited for video and image compression and transmission formats such as MPEG and JPEG. Historically, YUV and Y′UV were used for referring to analog television systems. The scope of the terms Y′UV, YUV, YCbCr, YPbPr, etc., is sometimes ambiguous and overlapping. 8.5 Y′UV420sp (NV21) to RGB conversion (Android).5 Luminance/chrominance systems in general.See the equations below or compare the historical development of the math. Likewise, U and V were chosen to differentiate the U and V axes from those in other spaces, such as the x and y chromaticity space. This lends itself naturally to the usage of the same letter in luma (Y′), which approximates a perceptually uniform correlate of luminance. The use of the letter Y for luminance can be traced back to the choice of XYZ primaries. Color information (U and V) was added separately via a subcarrier so that a black-and-white receiver would still be able to receive and display a color picture transmission in the receiver's native black-and-white format, with no need for extra transmission bandwidth.Īs for etymology, Y, Y′, U, and V are not abbreviations. Previous black-and-white systems used only luma (Y′) information. Y′UV is used in the PAL analogue color TV standard (excluding PAL-N).

The closely related Y′UV model uses the luma component (Y′) – nonlinear perceptual brightness, with the prime symbols (') denoting gamma correction.

It can be used to convert to and from the RGB model, and with different color spaces. The YUV model defines one luminance component (Y) meaning physical linear-space brightness, and two chrominance components, called U (blue projection) and V (red projection) respectively. Today, the term YUV is commonly used in the computer industry to describe colorspaces that are encoded using YCbCr. Historically, the terms YUV and Y′UV were used for a specific analog encoding of color information in television systems.

It encodes a color image or video taking human perception into account, allowing reduced bandwidth for chrominance components, compared to a 'direct' RGB-representation. YUV is a color model typically used as part of a color image pipeline. An image along with its Y′, U, and V components respectively