In Adobe Photoshop, filters are individual algorithms (or behind the scenes calculations) that alter the appearance of an image. For example, a simple filter might blur a selection, while an advanced filter could make a photograph look like a hand-drawn sketch.
In this guide, we explain what Photoshop filters are, and what each one does. Helping you make your images look better than ever.
NB: We used Adobe Photoshop 2020 for this article. The article also assumes a basic working knowledge of Photoshop’s user interface, so it will not cover Video Filters, the Filter Gallery, or the Blur Gallery.
1. Photoshop Blur Filters
When you’re trying to figure out the purpose of filters in Photoshop, the Blur category is the easiest one to explain. The general idea is to soften the image, but each particular filter under the category uses a different softening approach.
This filter finds the average color within a selection, then fills the entire selection with that color.
The blur filters average out the pixels next to hard lines and defined edges. This effectively smooths the transition of those edges and reduces noise.
Blur More does the same thing as Blur, but it increases the effects of the Blur filter and makes them more visible.
With Box Blur, every pixel is softened by the average color of its neighboring pixels within a set radius. The larger the blur radius, the stronger the effect.
Gaussian Blur is a quick blur tool that uses the weighted color average of all pixels in a selection. The resulting effect is similar to looking at the original image through a hazy-but-translucent screen.
Lens Blur replicates the depth of field that one can get when using a camera. If you are confused over the purpose of various filters in Photoshop, especially this one, in simpler terms it means:
Lens blur helps certain objects stay in focus, while others are blurred out. It’s almost as if you’re seeing objects at a distance, and your eyes are focusing on particular things.
To learn more about this phenomenon, check out our beginner’s guide to digital photography.
Motion Blur is the ability to blur a picture in a particular direction at a given intensity. It can sometimes look like the blur that you see when an object is moving very fast. Think of it like taking a photo with a very long exposure time.
Radial Blur creates a blur that moves in a circular direction, either using Spin mode (as if the image were spun around a certain point), or in Zoom mode (as if the image was rushing at you).
“Shape” blurs an object according to a custom design. You can find several custom shape presets available right out-of-the-box on Photoshop, but there are plenty of third-party apps, too.
Smart Blur blends similar pixels together according to a given threshold. This often creates a pastel effect that flattens the image. The larger the threshold, the flatter the image.
Surface Blur blends pixels together, but avoids edges or leaves those edges intact. It’s great for smoothing out an object’s appearance without losing its shape or definition.
2. Photoshop Distort Filters
While the previous section might have seemed long, in fact, we’re just getting started. There are still a lot of filters in Photoshop to cover!
After Photoshop’s Blur filters, the Distort category comes in. Distort provides reshaping effects to an image. Basically, it takes the image and “moves” the pixels around without any kind of blending or blurring. Here’s a list of what each preset does:
Displace shifts the pixels according to a displacement map. A displacement map is a special kind of image that dictates the movement of each pixel.
The Pinch filter squeezes the outside of an image towards the center of that image, as can be seen below.
Polar Coordinates convert the position of an image’s pixels from rectangular coordinates to polar coordinates. This makes the image look like it’s being reflected off a metal sphere.
Ripple alters the selection so that it looks like the image is rippling along the surface of a body of water.
Wave is a more advanced version of the Ripple filter. It provides greater control.
Shear transforms an image along a hand-drawn curve, which makes it great for custom images.
This filter makes the selection look as if it’s bulging out of the screen in a spherical shape.
Twirl spins the selection around its center, but does this action more intensely towards the center, and less intensely on the edges.
Finally, Zig Zag distorts a selection radially around the center. However, it uses a zig-zag pattern instead of straight circles.
3. Photoshop Noise Filters
In image processing, “noise” refers to pixels that have incongruous color values. In many cases, these colors are randomly distributed. Think of it as a marriage between television static and a kaleidoscope.
Add Noise creates pixels of random colors all across the image. Pixel distribution can be Uniform (strictly random), or Gaussian (according to the bell curve). It can also be monochrome.
Despeckle removes noise by blurring the image everywhere except where the edges are detected. Edges include any areas that have significant changes in color.
Dust and Scratches
This filter reduces noise across an image by finding areas where dissimilar pixels are located. It then adjusts them to be more similar.
This filter looks for pixels of similar brightness within the selection area, then discards pixels that are too dissimilar and applies a median brightness.
This filter preserves edges while reducing noise across an image.
4. Photoshop Pixelate Filters
Photoshop Pixelate filters take a group of pixels and turn the colors the same shade, which effectively makes them into one bigger “pixel” in turn. However, as always, different filters within this category take different approaches to how pixel groups should be combined.
This filter replicates the halftone effect by converting the image into a series of dots of varying sizes. Dot size is proportional to the brightness of that area in the image.
This filter combines pixels in certain areas to form a pattern of large, single-colored polygons, imitating a crystallization effect.
This filter groups similar-colored pixels together while retaining the general shape and form of the image.
Fragment takes every pixel in the selection, then:
- Multiplies that number by four.
- Takes the average color value.
- Offsets it from the original pixel position.
The result is something similar to a double-vision effect.
Mezzotint is a feature that roughens up an image according to one of several patterns that you can choose from. Black and white patterns are used in grayscale images, while saturated colors are used in color images.
Looking for an easy way to make pixelated art? Mosaic groups similar pixels together into square blocks. Each block becomes one color that represents all of the pixels that were joined to form that block.
This filter fills up the image with the current background color, then recreates the image using dots while leaving a few small spaces empty.
The final result resembles a pointillism painting, as can be seen below.
5. Photoshop Render Filters
Unlike the other filters in Photoshop that we listed, Render generates entirely new effects from scratch that are independent from the image itself.
This filter creates a cloud-like pattern using the current foreground and background colors.
This filter does the same thing as the regular Clouds filter, but follows it up by applying the resulting cloud pattern to the current selection using the difference blending mode.
The Fibers filter is a really neat tool that creates a cloth-like pattern, using the current foreground and background colors.
Circular Lens Flare simulates what happens when a light is shined into a camera.
This filter transforms the image as if different kinds of lights were being shined on it. It comes with 17 different presets, but you can also create your own.
6. Photoshop Sharpen Filters
This group is the opposite of the Blur category. When an image is sharpened, pixels of similar colors are altered to improve contrast, which reduces the appearance of softness.
Shake Reduction is a handy filter that helps you reduce the shaky camera motion or blurring effect that you sometimes see in photographs.
This filter improves clarity by reducing blur and increasing contrast.
This filter has the same effect as Sharpen, but amplifies and makes the filter effects stronger.
This filter detects any edges in an image. Then it sharpens them by increasing contrast, while non-edges are left untouched.
Similar to Sharpen Edges, this filter provides variables that you can adjust for more precise control over the contrast adjustment.
This is a more advanced algorithm for sharpening. It grants you control by opening up a brand new dialog box and letting you adjust the variables involved.
7. Photoshop Stylize Filters
Stylize filters are probably our favorite filter category, in that these filters creates some of the most memorable effects.
Diffuse moves around pixels to soften the focus of a selection. There are four different categories of Diffuse filters: Normal, Darken Only, Lighten Only, and Anisotropic.
Emboss makes a picture look like an object has been raised on a metal surface by converting all fill colors to a monochrome shade.
Makes a selection look 3D.
Locates the edges in an area, traces them, and creates an outline around that image.
The Oil Paint filter is a perfect filter for any budding artist to try out. With this filter, you can turn any selection or image into an impressionist painting.
Solarize takes an image and blends its negative and positive values together.
Tiles takes an image and cuts it up into multiple squares.
This filter locates the brightest areas in your image and outlines them to create a contour map.
Lastly, wind breaks up your image along a horizontal grid to create a “windblown” look.
Use These Photoshop Filters to Improve Your Images
Filters are a foundational component of Photoshop, and learning what each one does is a significant step towards mastery of the program.
Without any knowledge or experience with Photoshop filters, your Photoshop skillset is more limited than you might think. So don’t be afraid to scroll up and study them again.
Read the full article: A Newbie’s Guide to Photoshop Filters and What Each One Does