Real images practically always have defects. As you already know, at recovery pitch and color balance, and also visibilities are desirable for leading correction with the image entirely to influence all details in coordination. After performance of these operations when the image acquires optimal characteristics, the operation stage begins following, more thin.

First of all it is necessary to get rid of noise which the dust, small царапинки, hairs concerns; a raster (received at scanning of printing originals); grain for strongly increased facsimiles; the characteristic regular structures ("small squares" and a color dirt), arising at file saving in format JPEG with the uprated compression and etc. For liquidation of similar artifacts in the image are used the filters of blur destroying details.

It is necessary to raise the general sharpness of the image a little at least. If it is insufficient. Sharpness can be lost at any operations with the image, at scanning and especially as a result of usage of filters of removal of noise. For the images intended for printing, sharpness is better for making uprated. At the press color blurs a little, and superfluous sharpness is eliminated. If the store on sharpness is not present, the print will be blurred.

Then research the image. Often happens that сюжетно important sections too dark or too light, and tone change under all image leads to deterioration of other areas. Then try to adjust carefully pitch balance of a problem section. Selective equalization is actual, if the image has non-uniform lighting, flares because of incorrectly selected conditions of shooting or inaccurate display. If it is not possible to eliminate defect by means of masking and the subsequent correction of the selected areas, use special tools of correction. Cases of local color correction meet very rarely, they are connected to achievement of special effect, removal of superfluous color after pitch correction and so forth

After the image became qualitative, similar to a reality, it is necessary to achieve the best expressiveness. Сюжетно important details visually select, increasing their sharpness, instead of sections representing interest, on the contrary, process the blur filter.

Unnecessary details (any object casually got to a frame), or on the contrary, missing important fragments (the section is erased or the corner is torn off) reduce expressiveness of a frame. In many cases of an error of the informative plan it is possible to liquidate special receptions.

Filters are special small units, each of which is oriented on performance of special action. There are filters for gain and for sharpness lowering, for distortion, decreases of number of the colors, some of them on the basis of the image create the simplified picture, imitate lighting and etc. a considerable quantity of filters enters Into set Photoshop with the most different possibilities. For Photoshop the huge number of vendors worldwide is engaged in creation of additional units. These additional units. (In English them name Plug-Ins, or, on a slang, "plug-ins") can be connected to your program, and expand its graphic possibilities even more. It will be a question of connected units more low in this chapter.

Commands of all filters, both entering into set Photoshop, and connected, are in menu Filter (Filter). They are arranged on lexical sets (submenu). In the given section us three groups of filters will interest:

• Sharpen (Sharpness) — sharpness increases
• Blur (Blur) — lowerings of sharpness, blur
• Noise (Noise) — adding and noise removals

All filters of gain of sharpness operate on the similar mechanism. Certainly, they do not return in the image of missing details, contrast gains between separate пикселами. Details, thus, become more contrast that the eye perceives as sharpness increase. Three filters from four, entering into group Sharpen (Sharpness) are commands of direct action, they do not demand additional setting.

• · Sharpen (Sharpness) — raises sharpness at the expense of gain of contrast adjacent пикселов.
• · Sharpen More (Sharpness plus) — fulfills the same operation, but operates more strongly.
• · Sharpen Edges (Sharpness of edges) — finds in the image of area with the considerable changes of color or tone (boundary) and strengthens and without that the high contrast, thus all remaining sections (with the smooth passages) are saved without change.

Let's work with commands of gain of sharpness:

1. Open file Holiday jpg from the worker of a diskette. The image insufficiently sharp. We assume that it is a portrait, and all characters, except the sitting old woman, are insignificant. Hence, to adjust sharpness it is necessary selectively, strengthening it only for a head of the heroine.

2. Select tool Rectangular Marquee (Square-topped selection) the fragment of the image including the person of the old woman, and come under influence of all three above-named filters.

Pay attention that action of filters increased sharpness for, images of the person (and it is good), and also for the selected area round the person (that is already bad). Besides, in a photo there was an accurate rectangle, in which sharpness more than outside. Thus, at usage of filters with reference to the selected area it is necessary to do its exact selection and shading (if, of course, you do not wish to achieve special effect).

Filter Unsharp Mask (Planimetric sharpness) from groups Sharpen (Sharpness) allows to regulate sharpness gain. As a result of its application there is an unsharp masking: the program does an image copy, finds in it edges of areas with the considerable changes of color and tone and "points" them. It leads to gain of sharpness of boundaries and does not influence remaining ("equal") sections. On the basis of the received sharp image there is an unsharp mask which is superimposed on a little dim source image. The program, thus, deceives you not once, and twice: strengthening contrast of boundaries and blurring equal sections, she underlines a difference in between, and the eye believes that the image became indeed sharper. Filter Unsharp Mask (Planimetric sharpness) allows to achieve very convincing results at competent usage.

1. Select the person of the old woman with tool Magic Wand (Magic wand) and fulfill shading on 8 пикселов (fig. 9.1,).

2. Select command Unsharp Mask (Planimetric sharpness) from list Sharpen (Sharpness) of menu Filter (Filter) command Unsharp Mask (Planimetric sharpness). On the screen there is a dialog box with the same name (fig. 9.2). In its upper part the review field is allocated, it is very convenient for filter direct manipulation in parameters.

3. Transfer the cursor on the working image, it takes the form of an empty rectangle. Click on the image, and the selected fragment appears in a window of review of the filter.

4. Deliver the cursor in limits of a window of review, it takes the form of a hand. Pushing the mouse button, you can move the image in a review window. It is interesting that at the moment of relocation the image in a review window is shown in an initial type, without filter influence.

5. Push the button signed "plus" which is allocated under a review window. The image in a review window increases. As you guess, the button signed "minus" reduces the image. In the field between buttons the current scale in a review window is specified. To look at filter influence on the image in a document window, install flag Preview (Review).

6. Parameter Amount (Force) regulates a level of increase of contrast. Installing value of 100 %, you double existing sharpness, 200 % — once again double and etc. Observe filter action at different values in this field. Eventually stop on value of 100 % as for portraits higher values lead to gain of cosmetic defects of the person (specks, wrinkles).

7. The parameter in the field Radius (Radius) defines width of area round the found boundary. This value is set in the tenth shares пиксела. Radius — very important value. If to set its too big, it leads to loss of details, rough circuits and effect of a glow of edges. At unduly small radius filter influence will be insufficient. Install the value equal to unit.

8. Parameter Threshold (Threshold) installs minimum distinction of brightness levels and color which the filter defines as boundary: the threshold less, the more пикселов affects contrast gain. Set value equal 4. For the majority of images a threshold install in limits from 2 to 6.

9. Push the button APPRX. fig. 9.1, ^представлен result. At filter application observe following rules:

• · Raise sharpness after the demanded size and image resolution is set. Otherwise the subsequent changes of the size lead to loss of details or, on the contrary, to appearance of unnaturally contrast areas.
• · the sharpness Magnification is led before adjustment of a pitch range. Otherwise can it is irreversible to be lost details in светах and shades which any more it will not be possible to return visibility increase.
• · filters can be applied groups Sharpen (Sharpness) To gain of effect some times. However it is necessary to remember that contrast increase happens at the expense of reduction of an amount of pitch (color) levels that can lead to dips of levels in average tones.
• · At a radius choice it is possible to use an empirical rule:
• · to divide output image resolution on 200. In portraits it is very important not to uprate value of radius. On landscapes it is possible to apply a little increased radius, from it details will be more relief.
• · For images of the big size increase of parameter Amount (Force) to 250—500 % is admissible. For small images select values of gain of sharpness no more than 200 %, and parameter Radius (Radius) should not exceed 1 пиксел, differently there will be a glow of edges.

Operation, reverse to sharpness magnification, is a lowering of focus or blur. If at magnification of sharpness visibility between separate пикселами increases, at blur it decreases.

Blur filters помешены in group Blur (Blur) of menu Filter (Filter). Two filters from this list, Blur (Blur) and Blur More (Blur plus), like commands Sharpen (Sharpness) and Sharpen More (Sharpness plus), are operations of direct action. Filter Blur (Blur) slightly blurs the image, Blur More (Blur plus) does it more strongly.

More often use filter Gaussian Blur (Blur on the Gauss) with which we and work. For an illustration of action of this filter we lower sharpness of a background round characters in document Holiday Jpg opened at us.

1. Select tool Polygonal Lasso (Angular лассо) a background section, as is shown in fig. 9.3, and. Give to the selected area shading not less than 40 пикселов that there was no sharp transition.

2. Select filter Gaussian Blur (Blur on the Gauss) from list Blur (Blur) of menu Filter (Filter). In the dialog box with the same name (fig. 9.4) is a field of review with possibility of magnification of a level of blur and flag Preview (Review) of print preview of all image which needs to be installed. Scale Radius (Radius) regulates a blur level.

3. Moving a slider along a scale, observe result — as from almost inaudible blur at minimum values it is possible to pass to chaotic color stains in which the image is hardly guessed.

4. Install such value that background subjects were recognized, but out-of-focus. On fig. 9.3, a blur level it is equal 3,5 пикселам.

5. Save a file.

It is necessary to mention three more filters which are included in composition groups Blur (Blur). Filter Smart Blur (Clever blur) leaves invariable contrast boundaries and considerably blurs equal sections. To remove from the person of the person of a wrinkle, making it is younger for 20 years, or to clean its jacket, deleting stains and a dust — all it quite on forces to filter Smart Blur (Clever blur).

After handling by this filter the image becomes pure and bright, but objects take slightly lifeless, "sterile" form. Filter Smart Blur (Clever blur) is used in the same cases, as Gaussian Blur (Blur on the Gauss) — at creation of posters, cards, etc. when the attractive design is more important than facts of life.

Filters Motion Blur (Blur in driving) and Radial Blur (Radial blur) are applied to creation of effects. They blur the image not uniformly, and in a certain direction, on a straight line or on a circle. The blur level (fig. 9.5) is regulated.