What is mosquito noise?

It’s not just an ugly picture, it’s an old one. This time the interns got it about half right.

It should be perfect. I mean, your television screen should be like looking out a window. That’s why you bought the most expensive TV there is, right But sometimes it isn’t. There are several different problems that can happen to an otherwise pristine television picture, whether it’s HD or 4K or even if it’s just standard definition. Assuming you’re getting good signal and your TV is reasonably well calibrated, most of the flaws in the picture are due to compression artifacts.

Compression artifacts weren’t “a thing” until digital television started in the 1990s. First satellite, then cable, and finally over-the-air broadcasts went to digital and while the overall increase in quality was great, I guess that’s true what they say…”mo pixels mo problems.” (OK, I don’t know that anyone really says that.)

Compression artifacts come about because no one, not broadcasters, cable or satellite companies, sends out an uncompressed signal. A pure HD signal, totally uncompressed, would require a connection nearing 1,800Mbit/sec according to some calculations. A 4K signal could be up to 10Gbit/sec. These are not realistic numbers. Even with DIRECTV’s incredible satellite capacity, this would mean a total of about six channels. Something needs to be done to the signal in order to get it to a the point where all the channels you want can fit in the stream, whether that stream comes from a satellite, a wire, a strand of fiber, or over the air. A lot of math is required to get it down to size, and whenever you use a lot of math, there’s a possibility of “intentional errors.”

You see, a typical HD video stream is between 5 and 10 Mbit/sec, and 4K streams range from 30-60Mbit/sec. It takes a lot of work to get it down that low. Colors that you can’t see or perceive are thrown away, and large parts of the image that have no detail are smoothed over. Errors are put in, because they actually make things more compressible.


That’s right, intentional errors. Here’s how it works: let’s say you had five numbers: 24.345, 12.106, 6.31, 1.0933, and 29.1. You need to remember all of them. So, you just remember 24, 12, 6, 1, and 29. After all that’s “close enough.” Those are intentional errors. Often times numbers will be rounded up or rounded down to fit a particular mathematical model. The problem is, that when the image is decompressed, it’s not perfect any more.

Mosquito noise is the colorful name given to one of the problems shown in the image at the top of this article. Wherever there are cases where there’s a sharp contrast between two colors, those intentional errors look more obvious. Little bits of one color show up in the area where there should be the other color. When the image is moving, the resulting errors swarm around the image’s subject, almost making it look like it is surrounded by mosquitos.

If your image has mosquito noise, there isn’t a whole lot you can do about it. Proper calibration can make the image look its best but those artifacts are part of the signal you’re getting. You’ll notice them more if you have the sharpness turned up but they are always going to be there.

Proper calibration is one of the few weapons you have to fight mosquito noise. An image that’s properly calibrated will hide mosquito noise as the broadcaster intended, since it’s most likely to occur in the very bright or very dark parts of the image. Turning the sharpness down may seem like an odd way to get a better picture but an oversharpened picture won’t actually look better, it will just expose flaws that you weren’t intended to see.

Another option, if it’s available, is to choose a different source for your video. Right now the undisputed king of picture quality is UltraHD Blu-ray, but the content selection is slim. Regular Blu-ray discs have a lot more selection but that still pales compared to what’s available over satellite TV and popular streaming services. If conventional pay-TV is your choice, choose a provider with enough capacity so that they don’t overcompress the images. If streaming is more your bag, think about upgrading your internet speed. Most streaming providers have different quality levels and you’ll need a really fast service to take advantage of the best.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.