I. Introduction
In age-old times the granularity of the image, characteristic for a film photo, was possible poorly сымитировать in Photoshop with the help of the filter Add Noise. In later versions of this program the special filter Film Grain has appeared. But whether the new opportunities have appeared together with this filter? Whether really this filter can create similarity of a film grain? As far as the result will be better in comparison with old – kind Add Noise? In searches of the answers on these questions the author also has decided(solved) to lead(carry out) a little new « of small unscientific experiments ».
II. Allego
But what for to add to the image a grain and – or noise?
Reasonable question! You see quite often it is necessary to collide with an opposite task: how to make noise by less appreciable?
The reasons, after which the image after addition of noise is improved, can be a little:
1.The visual perception(recognition) of the man is arranged in such a manner that extended равноокрашенные of area eyes + brain » as unnatural, plastic, мультяшные often are perceived by system «. For this reason the image formed by digital chambers, often looks a little unnaturally, while the prints from a film are looked by more attractive for eyes.
In a traditional photo missing to an eye текстуры rather successfully simulates a grain of a film. The digital noise creates at the spectator completely other sensations. His(its) presence creates on the image inappropriate multi-coloured points, which зрительно not possible in any way ассоциировать with any natural текстурой.
However addition nobody of special noise to digital картинке in a number(line) of cases allows quite successfully to decide(solve) a task of creation of illusion that lost текстуры are restored.
2.Ещ ё one reason, on which to the image add noise, is the desire to compensate distortions caused by digital processing. For example, noise it is possible to disguise areas of inaccurate digital editing or «to “restore” текстуры after application of the filter Blur.
3.Sometimes it happens it is useful to add in картинку noise directly ahead of a seal. Business that the printers often растрируют the image by that or otherwise (that is, break it(him) in a new fashion into lines and elements), that can result in appreciable distortions of tones, of gradients etc. Addition of noise in some cases helps to overcome errors растрирования at a seal (that is, to make them by less appreciable).
4.The addition of noise in some cases can also increase зрительно perceived sharpness (see fig. 1 and 2).
Fig. 1. A fragment of the rather dim image Fig. 2. The same fragment, but with the added noise. Sharpnesses, certainly, has not increased. But зрительно many sites are looked as more precise. For certain there are also other bases for addition of noise in the digital image … Within the framework of a heading of the unscientific tests the author does not apply for completeness of a statement … However it is time already without superfluous meditations and теоретизирований to proceed(pass) to practical testing!
III. Анданте
In a fig. 3 the photo made by a digital soap tray is given. As it is visible, the absence of a film grain really does(makes) the image little bit “«plastic”.
Fig. 3. Яузские a gate.
Whether always it is bad? It is difficult to say … to Such images the aesthetics is peculiar. Sometimes they are very expressive. But in own way! At all how prints received by an optical image from a film or a plate.
To refuse such images in художественности — вс ё is equal, that scornfully concerns to анимационной the diagram! And you see many рисованные the animated staff являют by itself an example of the present art!
However, the author does not aspire to convince the reader in чём-or. It is more than opinions, good and different!
IV. Скерцо
In a fig. 4 and fig. 5 same staff is submitted after two variants of computer processing.
Fig. 4. Result after addition of noise with the help of the filter Add Noise Fig. 5. Result after addition of a grain with the help of the filter Film Grain In the beginning (fig. 4) the attempt сымитировать a grain by a traditional image with the help of the filter Add Noise was undertaken. For imitation of a grain the noise should be Gaussian and Monochromatic. The first condition as a matter of fact means, that than deviations(rejection) from face value — by that they more are less probable. The second condition means, that the noise will not result in sharp deviations(rejections) of colour in separate пикселях. Formally, both these conditions should ensure(supply) the closest imitation a film grain. However it is not necessary to accept вс ё on веру: in various practical situations it is possible to try to experiment and with other parameters of this filter. To indisputable advantages of function Add Noise it is necessary also to attribute(relate) an opportunity to vary parameter Amount to within the 100-th shares of percent(interest).
In a fig. 5 the result of application of the filter Film Grain (group Artistic) is shown. The auxiliary parameters Intensity and Highlight Area were established in a zero.
In both cases was chosen rather strong (but ещ ё acceptable) degree “«шумизации”: Amount = 2 and Grain = 2. The so large level of the added noise was called to simplify procedure of comparison and analysis of results. Also it is necessary to mean, that parameter Grain of the filter Film Grain can accept, alas, only integer meanings(importance).
At comparison of results it is not necessary « to drive by a nose on the screen of the monitor »: it is more reasonable to look on картинки from distance of the extended hand.
V. Ending
As it is easy to guess, within the framework of unscientific experiments of any categorical and certain conclusions will not follow. But some words on the rights of private(individual) opinion the author вс ё should say.
The experiment has shown, what even the special filter Film Grain simulates the present grain of a film far неидеально. And if to take into account, that parameter Amount can be exposed more precisely in the filter Add Noise, the appeal of the tool Film Grain becomes ещ ё less.
At the same time it is necessary to remember, that the author at all does not consider(count) itself as the professional in computer processing. Probably in more skilful hands the considered filters повели itself in another way.
Experiment independently! In this appeal — sense of all clauses published in a cycle « the small unscientific tests ».