No need to offend the "mattress"
I wish you a good day to the respected Habra community. This post is inspired by the post about the correct setting of the TV. I do not cherish high hopes that the “week of setting up TV sets on Habré” will suddenly begin, but I wanted to share some thoughts.
I draw your attention to the fact that the author is not a professional in the field of repair / adjustment of television receivers, monitors and other projection equipment, and all the above thoughts are only theoretical calculations with which more experienced comrades can easily disagree and reflect their resentment in the comments. For which, by the way, I will be very grateful, because it can seriously broaden my horizons.
Closer to the point
The picture given by me at the beginning of the post, experienced and not very TV people called the mattress. The name is undoubtedly more convenient than the “television setup signal,” although it is a bit offensive. Well, God bless him with the name, popular wisdom - it is limitless, since the mattress means it is useless to argue.
Vertical stripes are used to set up quite often, but most people who are “not in the subject” can hardly imagine what useful can be squeezed out of this trivial picture, and most importantly why some inventors out there didn’t guess at least place these stripes. in order, as in the rainbow, for example. I will answer, the rainbow is good, but it's useless for setting! The mattress is a versatile and easy way to set up both color and black-and-white TV, this very fact makes it crazy, fantastically kosher, halal and Orthodox at the same time (for atheist-minded citizens I will cite other synonyms: academic, correct, irreplaceable) .
A bit of theory
Everything stated in this section is the result of reverse engineering, so to speak in this situation. My acquaintance with the mattress was very interesting and instructive, I hasten to share with the community the results of my research.
In those days, when I got the Internet only on weekends or unexpected bursts of good mood from my bosses, when I had to keep huge piles of useful and not much information, and then rake it all up in the long evenings and strictly during off hours, when I could not ask google every little thing, it was then that engineering mind and appropriate education, gave the first shoots in the form of an understanding of the DAO Mattress.
The first thought, which gave direction for research, contained one simple truth - the stripes on TV were the same for everyone, and everyone had different TVs (I was still working, had a Slavutych-220 TV, and he was as it is known, black and white) . So in the arrangement of colors lies some mystery, the mystery of the ancients, the legacy of the wise, well, everything is in the same spirit.
So the light that we see has some basic characteristics, which you can easily think of independently, or with the help of literature. The light source for us is (in the context of the article) the TV / monitor screen or the reflected rays of the projector. What do we see? How do we see? Here are the questions that should be answered before you continue your journey.
The human eye separately distinguishes the brightness of the light beam and its tone. This is a scientific fact and I didn’t argue with him, I just armed myself and went to storm the mattress.
Popular wisdom says: "At night, all cats are gray." I agree, and also requires clarification that they are not equally gray. If you watch a black and white TV or just get out at night, it becomes clear that the color of objects disappears, and in return we get grayscale.
Brightness (or lightness , according to Wikipedia) , is one of the elements that opens the door leading to an understanding of the essence of the mattress.
I apologize to readers who may be slightly offended by chewing on common truths, but I do not do it from natural harm or the desire to offend someone, but simply state how I came to certain conclusions.
Solving the riddle of the mattress, I was in a slightly uncomfortable position, because I did not remember the charming sequence of its colored stripes, but I wanted to decide “here and now”, “without departing from the cash register,” well, or somehow less pathetic, but urgently and momentarily.
First I had to decide on the number of these same colors. As is well known in the human eye to different parts of the spectrum, different sensitivity ( metamerism ) , as well as some colors when mixed, form new, hitherto unseen hues. Here and the clue, I was happy, proud that I had recently read somewhere about such scary words for a simple layman as additive and subtractive.
Let's check a hunch, I thought then, and I wrote out on a piece of paper, familiar to everyone from childhood and inexpressibly beloved three colors: red, green and blue. Then I thought a little and added white to the list, as the sum of the three previous ones, and the fact that it was exactly the amount I had absolutely no doubt that I immediately demonstrated, backing up all the listed colors with hexadecimal codes (# ff0000, # 00ff00, # 0000ff, #ffffff) . About numbers, how much Divine beauty is in you.
Next, it was necessary to touch the mystery of inversion and get four more colors. Without further ado, I brought out
Further, returning to the first thought, I thought, but what to do with the order of these very colors?
Brightness decided everything for me, “let's add two and two”: there is a set of colors, there is a universality of the table, and as a result, of course, the brightness is sorted. In this case, one table can help in setting up both color and black-and-white equipment.
Brightness, contagion, you are such, well, on the whole, the direction of thought seemed perfect to me then, and I proceeded to the calculations (on paper, naturally) .
Not only did I know the scary words describing color models, knew how to use hexadecimal numerals and mathematics, I also knew three magic numbers that could help me in the long and thorny way of knowing the mattress. Let everyone remember and honor these three whales of all color manipulations - 0.30, 0.59, 0.11.
In fact, everything is very, very simple. This trinity is the sensitivity of our paired organ of vision to some parts of the visible spectrum, and specifically to the red, green and blue component. In sum, these three numbers give a unit, or 100%, if that’s convenient for you.
Having gathered together all the accumulated data, I was close to the final, as it seemed to me then.
And now, with one stroke of the pen, I will cut the number of readers in half:
L = 0.30 · R + 0.59 · G + 0.11 · B
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Here it is, here it is the formula of my dreams, and you can’t tell otherwise. Then everything went by gravity. It was not difficult to calculate all the indicators of brightness for eight colors, in this way the colors are converted to the gray scale, this gave me the strength and confidence that my path is true. Sorting took quite a bit of time and now before my eyes (in the form of a simple table, hastily arranged in a simple HTML file) , he appeared - his majesty Mattress.
White (white) - 255
Yellow (yellow) - 227
Turquoise (cyan) - 179
Green (green) - 151
Magenta purple - 104
Red (red) - 76
Blue (blue) - 28
Black (black) - 0
The brain prompted that everything was right, it was this picture that was stored somewhere in its depths and now, when comparing them, it confidently gave out “Successfully complete”, but for certain I, nevertheless, divided the table in half and added shades of gray to it, for all available colors. The result exceeded all expectations, the brightness of these halves seemed to me very, very similar. Anyone who reads these lines will undoubtedly think: “Why does the text go on?”
And then I had to go to the technique of setting up the equipment with just one table.
Some practice
One professor in our department said, and I remembered, an excellent phrase: “Understanding above memorization”. It was precisely this that motivated me, after all, having independently obtained the color table and having a sufficient basis for maneuvers, I grasped the ZEN Mattress. I do not consider the possibility of teaching mathematics in high school, but I insist that every reader, from the remaining lines, could be able to use such a simple and, like everything simple, ingenious tool for adjusting / calibrating the colors of output devices.
Actually everything is obvious. To adjust, we first need to remove the color saturation, that is, to force the equipment to display a picture in the gray scale - this will give us the opportunity to adjust the brightness and contrast. All that is needed is to achieve a clear distinction between the displayed lanes. Then you need to add color and get a subjectively clear picture of the primary colors, as far as your trained eye allows. By adjusting the normal display of the basic shades, we can guarantee that all the other tones and semitones will be displayed by the device precisely enough, well, or acceptable to us. Here is such a simple technique, derived from the results of short, but productive research.
Some common phrases
Sorry generously for excessive verbiage, I believe that even a near-scientific article should still contain a bit of an emotional component, so it can cause a greater response in the souls and minds of people.
PS
With the help of the method developed, I was able to adjust the picture on the TV (now in color) to an acceptable level, set up the projector normally at work, in general I began to apply it to the left and to the right. What you want.
Update
Given the comments of the community, I will make a brief summary of the notes in a more concise form.
The essence of the tuning table
- The mattress contains 8 color bands (three main + white, inversions of the previous four) , arranged in a strict and thoughtful order.
- The order of the bands is determined by the brightness of the colors used (gradation from brightest to least) .
- Following the logic of the do-it-yourself hub, consider the options for getting a tuning table:
- Create your own using any image editor or create a simple HTML-document.
:
#FFF, #FF0, #0FF, #0F0, #F0F, #F00, #00F, #000 - To assemble a generator of color bars “in the gland” (the technique in a schematic form is perfectly demonstrated by the user AndreyNagih , for which he thanks a lot )
- Create your own using any image editor or create a simple HTML-document.
Using
- Using the available hardware settings to remove color saturation. This step will show the mattress in grayscale. Adjust brightness and contrast to clearly distinguish all gradations.
- Add saturation and achieve normal (determined by the individual features of the vision and equipment) display the primary colors.
Pps
Many thanks for the kind words. I did not expect that this note will take place in the favorites of such a large number of users.
Source: https://habr.com/ru/post/143854/
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