How a Pixel Gets its Color | Bayer Sensor | Digital Image
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September 5th, 2009 |
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This video explains how pixels are assigned RGB values using a bayer filter system. It is one of the many bonus lessons on my new DVD, Photoshop Crash Course which will teach you how to think in Photoshop terms. This particular video was made to help explain how pixels are assigned colors and why this is important when working in Photoshop. I hope that you will enjoy it. Please be sure to visit my blog for free tips and photography information. If you are a beginner getting into photography …
24 Responses to “How a Pixel Gets its Color | Bayer Sensor | Digital Image”
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another great video … thanks michael
Great video!
One thing which might be obvious but it’s not emphasized is that the actual “megapixels” resolution of a digital camera sensor refers to the luminance, the colour resolution is less than 1/3 of that (reds are even less than that) due to the bayer matrix interpolation.
Only the Foveon image sensor can capture 1 colour information per pixel.
And some Sony CCDs have a 4 colour bayer filter (with an additional aqua sensel, instead of two green sensels).
anyway, thanks for sharing!
Very informational video.
The video says that nine sensels are used to represent a pixel.
But according to Wikipedia “Bayer Filter” entry, each individual sensel (Red,Green, or Blue) represents a pixel and the missing color data of each sensel is gathered
by interpolation( e.g., neighboring pixel).
Which is correct?
For example, would a 5 megapixel camera contain 5 million sensels or (5 million X 9) sensels?
a 5 megapixel camera will contain 5 million sensels.
Wikipedia is correct.
OK
I am not sure what the video is referring to at 02:35 when it describes the nine sensels required to represent a pixel…
Maybe it’s saying each sensel represents an individual image pixel, but that the value of every sensel is calculated by the value of neighboring pixels.
Thats a really good video.. also a good way of showing it woudl be to use the adjustment layer “channel mixer” as it would reflect your glass demo perfectly
The video and wiki are both correct. A 5 Mega pixel Camera has 5 million pixels, however, the final color of each pixel is interpolated by its neighboring pixels, otherwise it could only be pure red, pure blue or pure green. Each sensel does indeed represent a single pixel, but to determine its color, it needs help, 9 sensels are used in the calculation of a single, central (meaning the one in the middle) pixel.
Yes that is right. The words are carefully chosen. Its not 9 sensels represent a pixel, its nine sensels are involved in the calculation of a single, central target sensel and contribute their data to determining the final color. This is simplified with 3 sensels (the glasses) instead of 9.
Although I’m familiar with much of the subject material on your YouTube site, there were more than a couple “Oh wow, I didn’t know that”’s. LOVE your teaching approach and styles, very impressive!
Thank you Michael… a dvd or two are on my get-list!
That is *very* interesting. I can see now that by adjusting the values of R and G and B in an editing program such as PhotoShop, that critical colors will be accurate and I don’t have to rely on eyeballing my monitor. I can correlate them with an external aid such as a color wheel or chart that gives the respective values for the color I want.
Great presentation of your material. Thank you.
Darn! Science seems to have revised. Just decades back we were taught in a science experiment class that light is made up of 7 colors. This was even demonstrated by shining a flashlight through a triangle glass prism and then projected to sheet of paper.
ive been doing photoshop for a few years and just got into taking pictures. and this were all new information for me. Learned sometihg new
Michael you are a Maven!!!
I’ve known for a long time that a picture is combined of R.G.B but didn’t know how its done
so thanks very much!
P.S. you have great teaching techniques
lmao 5:48 – 5:55
nice tutorial I actually learned something useful for my work with photoshop
That was so helpful! Thanks so much!
Awesome, awesome, awesome!
The color spectrum contains 7 colors: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. (a.k.a. Roy G. Biv)
A digital camera is capable of processing 256 shades each of red, green and blue light for a total of 16.7 million possible colors.
The color spectrum nowadays was reduced to 3 colors: red, green and blue as demonstrated in Photoshop. You don’t need the 7 rainbow essence colors anymore to reproduce back sunlight or white light.
I’m currently working on a project that requires a red, green, and blue sensing photodiode. Not wanting to spend a lot of money, I’m buying three standard photodiodes and covering each one with either a red, green, or blue film.
Do you know where I could purchase rgb plastic films?
thanks for this
awesome video
you, sir, are just brilliant! wish my teachers are even half as effective as you are.
subscribed!
nice!! i learned a lot..