Displacement filter not mysterious-the substitution principle of the common solution displacement diagram

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Displacement filter not mysterious-the substitution principle of the common solution displacement diagram-for beginners to understand the replacement Filter FAQ

For displacement filters, many beginners cannot understand them for a long time.

What's the problem?

1. The first to blame PS designers, design is too impersonal (in fact, can be done, as long as the change algorithm design I think can be done.) Even if I would change, I wouldn't change it because AA

Bobe company won't give me commission! Unfortunately, I won't! ）

The translation of 2.ps Help file is a little too clear, the foreigner translation of things have this problem.

2. The problem has been like this, I think still want to blame oneself lack do experiment to grope, understand. The substitution principle of the replacement filter is not clearly understood.

This is no wonder that we need to do too much, competition is so fierce. There are so many idle Kungfu!

I am also idle all right, only then will be poor toss, the brain person's substitution has made a pass, also calculate has seen a little prospect. Here and beginners "vulgar solution" one time.

Or to say the replacement principle: (do not say no AH!) ）

PS Help in the following points on the replacement map. Note: [] is added by the author. What foreigners translate is hard to understand.

1. The "permutation" filter uses the color values in the displacement chart [in fact, by the specified channel's grayscale value] to change the selection [pixel movement]-0 is the maximum negative change value, 255 is the largest

Positive change value, gray value 128 does not produce permutation.

2. If the displacement chart [only] has one channel, the image changes [pixel movement] along the diagonal defined by the horizontal and vertical proportions.
If a displacement diagram has multiple channels, the first channel controls the horizontal [directional pixel] permutation, and the second channel controls the vertical [directional pixel] permutation.

3. When both the horizontal and vertical proportions are set to 100%, the maximum displacement is 128 pixels (because the middle Gray does not generate permutations).

4. Use an image called a displacement chart to determine how to distort a selection [pixel]. For example, an image created using a parabolic displacement pattern looks like it is printed on a two-angle, fixed-dangling cloth.

We can use the following diagram to simulate the above principle:

From the above figure, you can know that the displacement map can be a channel of black-gray-Bai map, can also be red, green two channels of black-gray-Bai diagram for production.

The movement law, all is changes with the gray level, presses the 45 degree diagonal to carry on the displacement movement. The picture size of the displacement chart can be large and small, without regulation.

In displacement, only the gray value is extracted as the basis for calculation.

You do not understand, it does not matter, slowly listen to me to give you an analogy, you will slowly understand.

I am here to the novice friend, in the most popular language to do an explanation:

What does a replacement filter do?

Didn't you see that the replacement filter made so many transformations, all sorts of strange, weird image transformations?!

You do not feel too mysterious, you first think of it as "calisthenics" performance good! That's how I see it.

Anyway, what does the replacement filter do?

I said the replacement filter is a moving company. You'll think there's something wrong with my nerves!

In fact, in essence, my understanding, by the most popular language: the replacement filter is the moving company, displacement filters are used to move. (or doing the "calisthenics" show)

Whether you do "fill" or "Stretch to fit," the truth is the same.

Here's a metaphor for "stretching to fit."

The picture is like a house, the pixel on the picture is like the furniture, the displacement picture is the owner to the porter to draw the moving map, but this diagram is according to "the substitution principle" uses "the gray Order diagram" this language

To describe. (Just like the "HTML" of that page). You say "html" I do not understand, that does not matter, please let me speak slowly!

If you say you don't even know how to move, don't look down! Or go to the children to play it!

The moving map tells the Porter this:

1. Tell the porter the scope of the move. (In this room, for example) (the constituency)

2. Tell the Porter: the left, right and top and bottom of each furniture are marked with a gray point. (The shades of gray are gray-scale values)

3. If the furniture is near the left, right, top and bottom 4 points of the "gray scale value" is 128, the furniture do not move.

4. When you move, either look at the left or the top two points, or look at the right and the next two points. Don't look too much.

5. If you are looking at the left and the top two points:

A. If you look at the gray point on the left first, if the gray point is larger than 128 gray, you move the furniture up, (moving distance is: (The point of gray-level value -128) x

replacement ratio); 128 Smaller, you move the furniture down, (moving distance: Gray level value on the point-128)

B. If you look at the gray point above, if the gray point is larger than 128, you move the furniture to the left, (the moving distance is: (Gray level value of point -128) x substitution ratio); smaller than 128, you move the furniture to the right, (the lifting distance is: The gray scale value of the point-128) (This understood bar, It's like playing a game! ）

6. If you are looking at the right and the bottom two points, moving the law is similar:

A. If you look at the gray point on the right, if the order of gray points is greater than 128, you're going to move this furniture up. (The Moving Distance is: (Gray level value of point -128) x substitution ratio); smaller than 128, you move this furniture down, (moving distance: Gray scale value on point-128)

B. If you look at the gray dots below, if the gray dots are larger than 128, you're going to move this furniture to the left. (The Moving Distance is: (Gray level value of point -128) x substitution ratio); smaller than 128, you move this furniture to the right, (moving distance: (Gray point value -128) x displacement ratio)

You always see it!

I think you are always smarter than a porter!

The above 5, 62 points of content, in terms of the term is called "reverse lookup." Here is just a mention, not to care about it!

Porter asked the host: "Moving distance is: The point of gray scale value-128" What does it mean?

The master told him: "For example, the grey point of the gray dot is 188, the moving distance is (188-128) x replacement ratio." If the replacement ratio is 20%, move 60x20%=12 pixels. (There is a horizontal displacement ratio and vertical displacement ratio, which is determined by the owner of the first)

The owner asked the porter: Do you understand me?

Porter said: ok!

Such an orderly move will begin!

In fact, the process of a replacement is the case.

The above is my "vulgar solution". I wonder if you understand? If you don't see it, please read it again!