PS Xiaobai: Is the "blur" filter stupid? How to use it?

Hello friends, do you often use the blur filter in PS? I often use Gaussian blur, because this filter can blur out unwanted things and highlight my key points. It's really a good filter! In fact, this kind of "blur" filter can create very diverse picture effects. As long as we know their functions, it is very convenient for us to draw pictures.

Take Photoshop CS6 as an example. Select "Filter-Blur" in the menu bar above, and you will see many different kinds of blur filters:

So many kinds of blur filters have different effects and application fields. Take this picture with white lines on a black background as an example (original):

Using different blur filters, the results are as follows:

"wow! So diverse and awesome! However, I am more confused ... "After reading some fuzzy renderings above, I believe many people will have this idea. Don't worry, now I will tell you the skills and practical uses of some commonly used fuzzy tools.

1. Gaussian blur

The core algorithm of Gaussian blur is normal distribution (also called Gaussian distribution), hence its name. Its blurring effect is obviously different from defocused lens imaging and general illumination shadow, just like observing an image through a translucent screen.

When you adjust the pixel value in the Gaussian blur filter, you can clearly see that the higher the pixel value, the more blurred the image.

Gaussian blur is often used to reduce the level of detail and reduce the influence of noise on photos.

2. The scene is blurred and the aperture is blurred

Scene blur can be used to create the effect of "large aperture focusing on objects" or to realize local blur of the scene.

After entering the scene blur interface, you can set multiple anchor points in the picture and adjust their blur radius in the toolbar with different anchor points as the center. For the part to keep clear, set an anchor point, and then set the blur radius to 0 pixels.

Another important application of scene blur is to adjust the "light source lens" and "lens color" in the "blur effect" column to create a lens overlay.

Aperture blur is similar to scene blur, but it is not so "free". Will produce a circular "aperture" area, resulting in the effect of "clear center and fuzzy periphery":

3. Radial ambiguity

Click on the radial blur and you will find that it contains two "blur method" options: rotation and scaling. They correspond to different fuzzy rules, and their use methods and purposes are different.

rotate

As the name implies, "rotation" can produce a dynamic blur effect similar to rotation in a specified area.

You need to use a pen, quick selection or polygonal lasso tool to select the desired area (for example, the tire part of a car), click radial blur-rotate, and then adjust the appropriate number.

It should be noted that the action rule of radial ambiguity is only valid for one region.

Take the above picture as an example. If you want the front and rear wheels to rotate at the same time, you must first select the front wheel and apply the rotary radial blur, then select the rear wheel and apply the rotary radial blur again.

If you want to save trouble, select the front and rear wheels at the same time and apply the rotation radial blur, the rotation center will be located in the middle of the two selection areas, and the rotation effect will be very strange:

scaling

Zoom radial blur, usually used to create a zoom effect (also known as "pop").

You just need to use the quick mask to select the part you want to keep clear (or select the area and then reverse it) and apply the zoom radial blur to create a dynamic trajectory effect:

4. Motion blur

After entering the dynamic fuzzy interface, you will see two options: angle and distance; The former determines the direction of the trajectory line, and the latter determines the length of the trajectory line.

Similarly, taking the automobile diagram as an example, we use the mask to select the automobile (or use tools such as lasso and quick selection to select the automobile, and then reverse the selection), and apply dynamic fuzzy:

The effect is as follows:

It can be seen that it is not good to set the "distance" too large-because there is obvious "tailing" around the edge of the car. If you must pursue a long trajectory, you should pay attention to the thinning of the edges when adjusting the selection.

5. Average ambiguity

The algorithm of average blur is special, similar to filling the current area with "average hue of the whole area". It is not widely used, but it can be effectively used to eliminate color cast.

Take this serious color photo as an example:

The first step is to copy the layer.

Step 2, use the average blur filter, then use ctrl+i to reverse, and adjust the layer blending mode to "soft light". The results are as follows:

Step 3, merge the layers, use the average blur filter again, invert Ctri+i, and adjust the layer blending mode to "overlay". The results are as follows:

If the adjustment result is not satisfactory, repeat the third step and adjust the opacity of the average blur layer to get the desired effect.

6. Blurred lens

Lens blur is one of the most "professional" blur filters, which can create the blur effect of shallow depth of field closest to the lens.

When using the lens blur filter, you need to crop the foreground by matting and create a mask (or reverse selection):

After applying the "lens blur" filter, such an adjustment interface will appear:

By adjusting the parameters (mainly shape, radius and blade camber), you can precisely control the blur effect of the background:

After reading these examples, do you find that PS is very powerful? Have you all learned how to use it? I have learned it, haven't I? Then I will test you. What blur filter is used in the first picture at the beginning of this article?