- Work with Grain effects
- Work with noise samples in Grain effects
- Working with added or matched grain
- Add Grain effect
- Dust & Scratches effect
- Fractal Noise effect
- Match Grain effect
- Median effect
- Noise effect
- Noise Alpha effect
- Noise HLS effect and Noise HLS Auto effect
- Remove Grain effect
- Turbulent Noise effect
Work with Grain effects
Almost every digital image captured from the real world contains grain or visual noise caused by the recording, encoding, scanning, or reproduction processes and by the equipment used to create the image. Examples include the faint static of analog video, compression artifacts from digital cameras, halftone patterns from scanned prints, CCD noise from digital image sensors, and the characteristic speckle pattern of chemical photography, known as film grain.
Noise isn’t necessarily bad; it’s often added to images to create a mood or tie elements together, such as adding film grain to a computer-generated object to integrate it into a photographed scene. However, noise can be unwanted for aesthetic reasons. Archival footage or high-speed photography may appear unpleasantly grainy; digital compression artifacts or halftone patterns may mar an image; or noise may interfere with technical processes such as bluescreen compositing.
Technical reasons also exist for reducing noise. For example, compression algorithms usually achieve smaller file sizes if the input material is less noisy, so noise reduction is a valuable preprocessing step for work such as DVD creation and video streaming.
The Add Grain, Match Grain, and Remove Grain effects allow you to manipulate grain that appears more or less evenly over an entire image. Grain effects can’t correct image problems that affect only a few pixels, such as dust, salt and pepper noise, or analog video dropouts.
The Add Grain effect generates new grain from nothing; it doesn’t take samples from existing grain. Instead, parameters and presets for different types of film can be used to synthesize different types of grain.
The Remove Grain and Match Grain effects use a two-step process to manipulate grain without affecting the edges, sharpness, or highlights of an image. First, the grain is sampled, either automatically or manually; second, the grain is analyzed and portrayed by a mathematical model, which the effect uses to add, remove, or match the grain.
Apply a grain effect
Each grain effect is applied with default settings and is displayed in Preview viewing mode, which has a preview region framed by a white border and centered on the image. The preview region displays the results of the grain effect on a portion of your image, for speed and comparison purposes. The grain effects are almost fully automatic but also offer many controls to achieve precise results. You can also selectively apply the grain effects to portions of your image using the extensive Blend With Original features provided with each effect.
Apply a grain effect to a selected area
- Color Matching
- Excludes any area of the image that matches a selected color. By inverting the matte, you can also selectively process such an area.
- Masking Layer
- Uses any layer in the current composition as a mask to selectively process or exclude an area of the current layer or track.
When any grain effect is first applied, the Amount value of the Blend With Original controls group is set to 0%; this value determines the percentage of blending between the original image and the processed version. At 0%, no blending occurs and the selected effect is applied to the entire image at full strength; at 100%, white areas of the blending matte are unchanged from the original image.
Any mask or matte works in a similar way: The white pixels in it exclude that area of the original image from processing by the grain effect; the black pixels process normally. At 100% Amount, the white areas fully blend with the original so that they are completely excluded from the processing. This behavior remains true when the match is inverted. Regardless of the Amount value, the black areas of the matte or mask are always processed. The Amount slider affects only the areas under the white pixels in the matte or mask. It affects only how each grain effect treats the white areas of the matte or mask.
Generate a color-matching matte
When a grain effect is first applied, a neutral gray color is used to generate a default color-matching matte, so that in most images a visible matte appears. The Color Matching group of controls uses color matching to precisely define a matte. The matte isolates portions of the image where the layer that uses the grain effect is blended with the input.
- To select a color to exclude from or restrict to the
effect, do one of the following adjacent to the Matching Color control
in the Blend With Original and Color Matching controls groups:
Click the color swatch and select a color in the Color Picker dialog box.
Click the eyedropper
and
click a color anywhere on the screen.
Generate a layer matte
In some cases, you may want to use a different layer or track as a mask for the layer that uses a grain effect. This type of mask allows unlimited control over exactly which parts of an image are modified and by how much.
Change the preview region
You can use the Preview Region controls group to change the position or the size of the preview region for a grain effect.
Because adding or removing grain can affect sharpness of detail, you may want to preview an area of fine detail, such as a human face or some text. When you remove grain with the Remove Grain effect, a best practice is to preview an area where the grain is most clearly visible or most objectionable, such as a large expanse of solid color.
You’ll achieve the best results by experimenting, applying small increments to each of several controls in the Effect Controls panel, and viewing the results in the Composition panel after every adjustment.
- After applying a grain effect, click the Center
button
in
the Preview Region group of controls in the Effect Controls panel. A cross hair is centered in the Composition panel.
- View the results:
To view the fine detail of the noise structure, zoom into the preview region.
To examine the noise in each channel independently, click the corresponding color channel icon in the Composition panel.
To increase the interaction speed and RAM preview duration, use the Region Of Interest feature in the Composition panel to reduce the area that’s processed. (See Region of interest (ROI).)
To retain an image of the current frame in its current state, click Take Snapshot
in
the Composition panel. You can then click Show Snapshot 
to
view the most recent snapshot instead of the active composition,
and to toggle between the current and previous states of the preview
region. This technique is extremely useful for evaluating subtle
adjustments. (See Snapshots.)To compare the preview region with and without the grain effect, click the Effect switch
next
to the name of the grain effect in the Effect Controls panel to
temporarily disable the effect. Click Take Snapshot in
the Composition panel, click the Effect switch again to re-enable
the effect, and then click and hold down Show Snapshot to
display the snapshot of the image without the effect.
Work with noise samples in Grain effects
Noise sampling is the first and most important step in removing noise from an image or in matching the noise of one image in another image. Normally, this process is entirely automatic. For fine control, you can switch to Manual mode and adjust the samples using the Sampling controls group in the Effect Controls panel.
A noise sample should be a solid block of uniform color that clearly displays the noise pattern present in the image. The objective is to extract samples of pure noise, without any image features that the algorithm could misconstrue as grain. For example, extract samples from a piece of sky, a background wall, or an area of fleshtone. All samples should be selected from the normal range of the film, DV, or video stock. Avoid underexposed or overexposed areas lacking in information, especially areas where pixel values have been clipped to pure black or white. Within this normal exposure range, it’s best to select samples with various RGB values and colors—for example, one sample from a bright area, one from a dark area, and one from an area with midtones.
The number of samples in automatic mode is high to ensure that the algorithm has enough good noise data, even if finding good samples in a particular image is difficult. In addition, automatic mode may override the number of samples you’ve set if the effect can’t find enough good samples. You can vary the size of the samples in either automatic or manual mode; however, increasing sample size doesn’t guarantee better results, especially if the resulting samples include more substantial variations in RGB values. Sample size should be reduced if a particular image doesn’t contain sufficiently large areas of constant color values. Conversely, increasing the sample size may give better results if the image contains large featureless areas.
Manually reposition noise samples
Automatic grain or sample selection generally gives acceptable results for the Match Grain or Remove Grain effect, but you can choose to manually position and resize each sample or change the sample number. For example, you may want to reposition samples if the automatic sampling selected a uniform area that is underexposed or overexposed and that lacks information about grain structure.
Noise samples for the Match Grain and Remove Grain effects are always extracted from the source layer without regarding any effects or masks already applied to the layer; this method results in more accurate sampling. If you want the samples to include the existing effects, precompose or pre-render the source layer with the effects and then apply the grain effect to the resulting source layer.
Avoid sample areas with the following characteristics: sharp edges, color gradients, highlights, textures such as grass or water ripples, fine detail such as hair or tree leaves, and overexposed or underexposed areas lacking in information.
- To move a noise sample, do one of the following:
Click the point parameter
for
the noise sample in the Noise Sample Points controls group. A cross
hair appears in the composition, centered on that sample. Click
the desired location in the Composition panel to place the sample.Using the Selection tool
, drag
the sample point in the Composition panel to the desired location. Enter the desired horizontal and vertical coordinates in the Effect Controls panel.
Note: The number of sample points that are enabled corresponds to the current value of the Number Of Samples.
Change the sampling source frame
By default, the Remove Grain and Match Grain effects take noise samples from the first frame of the layer, but you can choose to sample the noise from a different frame. Changing the frame may be useful if large lighting or exposure variations occur between frames within the layer.
Change the noise sample box color
You can set the viewing mode for the Remove Grain or Match Grain effect to Noise Samples to see the areas sampled by the effect. Sampled areas are automatically framed with a white outline. If you prefer, you can change the color of these noise sample boxes.
Next to the Sample Box Color control in the Sampling
controls group, do one of the following:Click the color swatch, and select a color in the Color Picker.
Click the eyedropper, and click a color anywhere in the application window.
Working with added or matched grain
The Add Grain effect creates new grain or noise in an image by building the grain from nothing or by basing the properties of the grain on presets. The Match Grain effect also creates new grain in an image but by matching the grain in a different image. Both effects share several controls in the Effect Controls panel that let you control the color, tonal range, blending mode, and animation properties of the grain.
Adjusting the tones of added or matched grain
The precise grain pattern present in any frame of film isn’t uniform throughout the frame but may depend on the tonal values of the content at each pixel. For example, in chemical film grain, the sizes of the silver halide crystals vary with the exposure level.
The Add Grain and Match Grain effects let you reproduce these subtle changes in grain patterns across areas of an image by using the Shadows, Midtones, Highlights, and Midpoint controls in the Application controls group. These controls let you define how much grain is added to each tonal area and also to each channel in the image. For example, you can add more grain to overexposed areas of the blue channel to give an image of sky a grainier look.
You can use the Application controls group for the Add Grain or Match Grain effect to do the following:
To define how much grain is added to each tonal area in an image, adjust the Shadows, Midtones, and Highlights values.
To define the midpoint of the tonal range of the image for grain application purposes, adjust the Midpoint slider. By default, this slider is centered at 0.5, which represents the middle of the range of pixel values—127 for 8-bpc images and 16384 for 16-bpc images.
For even finer control, use the Channel Balance controls to adjust the grain in the shadow, midtone, and highlight areas independently for each channel.
Animating added or matched grain
By default, the grain or noise generated by the Add Grain and Match Grain effects moves at the same speed as the source material to accurately simulate realistic noise. Slowing down the noise processes may be useful for aesthetic effect or to keep the added noise from buzzing and drawing attention to itself. These effects have an internal randomizer that changes the positions of the noise pixels between frames. But you can also change the appearance of the noise between layers on the same frame while keeping every other parameter constant.
You can use the Animation controls group for the Add Grain or Match Grain effect to do the following:
To specify the frame rate of the added grain, as a multiple of the destination frame rate, adjust the Animation Speed value in the Animation controls group in the Effect Controls panel. At higher Animation Speed values, the lifespan of the grains is lower. At the default value of 1, the grain moves at the same rate as the frames. At lower values, the grain changes more slowly, which can be useful for giving the appearance of film grain. At zero, the grain is stationary over time.
To use interpolation to create smooth transitions between the generated noise frames, select Animate Smoothly. This control matters only if Animation Speed is less than 1.
To change the appearance of the noise between layers on the same frame, adjust the Random Seed value. Each Random Seed value represents one of 100 possible variations in the appearance; changing the value doesn’t make the results more or less random.
Blending and adjusting the color of added or matched grain
You can adjust the color, saturation, and blending behavior of the grain generated by the Add Grain or Match Grain effect.
Several factors can affect the apparent color of the grain that these effects generate, including the following:
The color value of the underlying pixel in the source image.
The Saturation value of the noise.
The Tint Color and Tint Amount values, if you have modified these settings from the defaults.
The Blending Mode value in the Application controls group.
The amount of noise applied, if any, to each channel individually using the Channel Intensities controls group.
Using the Color controls group in the Effect Controls panel, you can adjust any of the following:
- Monochromatic
- Gives the added noise a single tint. By default, the tones are black and white, but you can change the Tint Color to make it a gradient of any color. (The Saturation and Channel Intensities controls aren’t available if Monochromatic is selected.)
- Tint Amount
- Controls the depth and intensity of the color shift.
- Tint Color
- Controls the color the added noise shifts toward.
- Saturation
- Controls the amount and vividness of the color.
The Blending Mode in the Application controls determines how the color value of the generated noise combines with the color value of the underlying source layer at each pixel:
- Film
- Makes the generated grain appear embedded in the image. This mode affects darker colors more than lighter ones, just as the grain in a film negative appears.
- Multiply
- Multiplies the color values of the noise and the source. However, the result may be either lighter or darker than the original, because the noise may have either a positive or negative value.
- Add
- Combines the color values of the pixel in the source with the noise. However, the result isn’t always lighter than the original because the noise created by grain effects can have either a positive or negative value.
- Screen
- Multiplies the inverse brightness values of the noise and the source. The effect is like printing from a multiple exposure on a negative. The result is always brighter than the original.
- Overlay
- Combines the behavior of Film and Multiply: Both shadows and highlights get less grain, while midtones get a full application of grain.
Add Grain effect
The Add Grain effect generates new noise from nothing and does not take samples from existing noise. Instead, parameters and presets for different types of film can be used to synthesize many different types of noise or grain. You can modify virtually every characteristic of this noise, control its color, apply it to the image in several ways, even animate it or apply it selectively to only a part of your image.
This effect works with 8-bpc and 16-bpc color.
The distribution of the added noise over the color channels does affect the overall color of the resulting image. With a dark background, the noise tends to add to the image visually, so a red tint or more noise in the red channel gives a reddish hue to the image. With a bright background, the noise tends to subtract from the image visually, so a red tint or more noise in the red channel gives a cyan color. The result also depends on the Blending Mode control in the Application controls group.
You can use the controls for the Add Grain effect to do the following:
To reproduce the grain of a particular film or photographic stock, choose the film type from the Preset menu for the Add Grain effect in the Effect Controls panel.
To adjust the intensity and size of the applied grain and introduce a blur, adjust the Tweaking controls group for the Add Grain effect in the Effect Controls panel.
To modify the color of the added noise, adjust the Color controls.
To define how the color value of the generated noise combines with the color value of the underlying destination layer at each pixel, choose a Blending Mode in the Application controls group.
To define how much grain is added to each tonal area in your image and the midpoint, adjust the Shadows, Midtones, Highlights, and Midpoint values in the Application controls group.
To animate the added grain, adjust the properties in the Animation controls group.
To apply the effect to the entire image, choose Final Output from the Viewing Mode menu.
Tweaking controls for Grain effects
The Match Grain and Add Grain effects share a group of Tweaking controls. You can use these controls to modify the intensity and size of the noise and to introduce a blur, all of which can be done across the three channels or individually for each channel. You can also change the aspect ratio of the applied grain.
Adjust any of the following controls in the Tweaking controls group:
- Intensity
- Controls the amount of variation in brightness and color strength between pixels in the generated noise, which determines the visibility of the noise. Increasing the value does not change the position or size of each grain but makes the grain appear to pop more; lower values give a more subtle muted appearance.
- Channel Intensities
- Controls the contrast between pixels in the generated noise separately for each channel. For example, you may want to add more grain to the blue channel to emulate film.
- Size
- Adjusts the size of the generated grain in pixels.
- Channel Size
- Adjusts the size of the generated grain in pixels independently for each channel.
- Softness
- Sets the amount of softness in the grain.
- Aspect Ratio
- Controls the ratio of the width of the generated grain over a constant height of 1; this setting is useful for emulating the effect of anamorphic lenses or for aesthetic effects. A value higher than 1 stretches the grain horizontally; values smaller than 1 squash it horizontally.
Dust & Scratches effect
The Dust & Scratches effect reduces noise and defects by changing dissimilar pixels within a specified radius to be more like their neighboring pixels. To achieve a balance between sharpness of the image and hiding defects, try various combinations of Radius and Threshold settings.
This effect works with 8-bpc and 16-bpc color.
- Radius
- How far the effect searches for differences among pixels. High values make the image blurry. Use the smallest value that eliminates the defects.
- Threshold
- How different pixels can be from their neighbors without being changed by the effect. Use the highest value that eliminates the defects.
Fractal Noise effect
The Fractal Noise effect uses Perlin noise to create grayscale noise that you can use for organic-looking backgrounds, displacement maps, and textures, or to simulate things like clouds, fire, lava, steam, flowing water, or vapor.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
The Evolution controls create subtle changes in the shape of the fractal noise. Animating these controls results in smooth changes of the noise over time, creating results that resemble, for example, passing clouds or flowing water.
Chris Zwar provides an article on the Creative COW website that explains how the Fractal Noise effect works, including many details and images regarding the inner workings of the effect.
Stu Maschwitz provides an example project on his ProLost blog that uses the Fractal Noise effect to create the corona of the Sun.
Harry Frank provides an animation preset on the AE Freemart website that uses Fractal Noise to create a star field.
Maltaannon (Jerzy Drozda, Jr.) provides a video tutorial on the Creative COW website that shows how to use the Fractal Noise effect to create a star field and then use a star field as a skybox to provide a distant backdrop in a 3D world.
The Turbulent Noise effect is essentially a modern, higher-performance implementation of the Fractal Noise effect. The Turbulent Noise effect takes less time to render, and it’s easier to use for creating smooth animations. The Turbulent Noise effect also more accurately models turbulent systems, with smaller noise features moving more quickly than larger noise features. The primary reason to use the Fractal Noise effect instead of the Turbulent Noise effect is for the creation of looping animations, since the Turbulent Noise effect doesn’t have Cycle controls.
Controls
- Fractal Type
- The fractal noise is created by generating a grid of random numbers for each noise layer. The Complexity setting specifies the number of noise layers. The Fractal Type setting determines the characteristics of this grid.
- Noise Type
- The type of interpolation to use between the random values in the noise grid.
- Invert
- Inverts the noise. Black areas become white, and white areas become black.
- Contrast
- The default value is 100. Higher values create larger, more sharply defined areas of black and white in the noise, generally revealing less subtle detail. Lower values result in more areas of gray, softening or muting the noise.
- Overflow
- Remaps color values that fall outside the range of 0–1.0,
using one of the following options:
- Clip
- Remaps values so that any value above 1.0 is displayed as pure white, and any value below 0 is displayed as pure black. The Contrast value influences how much of the image falls outside this range. Higher values result in a mostly black and/or white image with less gray area. Therefore, higher contrast settings display less subtle detail. When used as a luma matte, the layer has sharper, better-defined areas of transparency.
- Soft Clamp
- Remaps values on an infinite curve so that all values stay in the range. This option reduces contrast and makes noise appear gray with few areas of pure black or pure white. When used as a luma matte, the layer contains subtle areas of transparency.
- Wrap Back
- Remaps triangularly, so that values above 1.0 or below 0 fall back into the range. This option reveals subtle detail when Contrast is set above 100. When used as a luma matte, the layer reveals more detailed textured areas of transparency.
- Allow HDR Results
- No remapping is performed. Values outside the range of 0-1.0 are preserved.
- Transform
- Settings to rotate, scale, and position the noise layers. The layers appear as if they are at different depths if you select Perspective Offset.
- Complexity
- The number of noise layers that are combined (according to
the Sub Settings) to create the fractal noise. Increasing this number
increases the apparent depth and amount of detail in the noise.Note: Increasing Complexity results in longer rendering times. If appropriate, try reducing the Size rather than increasing Complexity to achieve similar results and avoid longer rendering. A trick to increase apparent complexity without increasing rendering time is to use a negative or very high Contrast or Brightness setting and choose Wrap Back for Overflow.
- Sub Settings
- The fractal noise is generated by combining layers of noise.
The Sub Settings control how this combination occurs and how the
properties of the noise layers are offset from one another. Scaling
successive layers down creates finer details.
- Sub Influence
- How much influence each successive layer has on the combined noise. At 100%, all iterations have the same amount of influence. At 50%, each iteration has half as much influence as the previous iteration. A value of 0% makes the effect appear exactly as if Complexity is 1.
- Sub Scaling, Rotation, and Offset
- The scale percentage, angle, and position of a noise layer relative to the previous noise layer.
- Center Subscale
- Calculates each noise layer from the same point as the previous layer. This setting can result in the appearance of duplicated noise layers stacked on top of each other.
- Evolution
- Uses progressive revolutions that continue to change the
image with each added revolution. This method is unlike typical
revolutions that refer to a setting on the dial control for which
the result is the same for every multiple of 360°. For Evolution,
the appearance at 0° is different from the appearance at 1 revolution,
which is different from the appearance at 2 revolutions, and so
on. To return the Evolution setting to its original state (for example,
to create a seamless loop), use the Cycle Evolution option.
You can specify how much the noise evolves over a period of time by animating Evolution. The more revolutions within a given amount of time, the more rapidly the noise changes. Large changes in the Evolution value over a short period of time may result in flashing.
To create a seamless loop, use Cycle Evolution, and set Evolution keyframes at full revolutions with no degrees—partially completed revolutions may interrupt the loop.
- Evolution Options
- Options for Evolution.
- Cycle Evolution
- Creates a cycle of Evolution that loops over the set amount
of time. This option forces the Evolution state to return to its
starting point, creating a smooth progressive cycle, a nonrepeating
cycle, or a loop segment.
To ensure that a cycle completes full revolutions, choose a Cycle value that either matches or is evenly divisible by the number of revolutions set for Evolution.
- Cycle (in Revolutions)
- Specifies the number of revolutions that the noise cycles through
before it repeats. The amount of time between Evolution keyframes determines
the speed of these Evolution cycles. This option affects only the evolution
of the noise, not Transform or other controls. For example, if you
view two identical states of noise with different Size or Offset
settings, they don’t appear the same.Note: Cycle is available only if Cycle Evolution is selected.
- Random Seed
- Sets a random value from which to generate the noise. Animating the Random Seed property results in flashing from one set of noise to another (within that fractal type), which is usually not the result that you want. For smooth animation of noise, animate the Evolution property.
You
can easily create new fractal noise animations by reusing previously
created Evolution cycles and changing only the Random Seed value.
Using a new Random Seed value alters the noise pattern without disturbing
the Evolution animation. Instead of animating
Evolution over the entire composition, save rendering time by prerendering
and looping one short Evolution cycle for the duration you want. - Opacity
- Opacity of the noise.
- Blending Mode
- The blending operation between the fractal noise and the original
image. These blending modes are identical to the ones in the Modes column
in the Timeline panel, with the following exceptions:
- None
- Renders the fractal noise only and does not composite on the original layer.
- Hue
- Renders the fractal noise as hue values instead of grayscale. The Saturation and Lightness of the original layer are maintained. If the original layer is grayscale, nothing happens.
- Saturation
- Renders the fractal noise as saturation values instead of grayscale. The Hue and Lightness of the original layer are maintained. If the original layer is grayscale, nothing happens.
Match Grain effect
The Match Grain effect matches the noise between two images. This effect is especially useful for compositing and in bluescreen/greenscreen work. The Match Grain effect only adds noise and can’t remove it, so if the destination is already noisier than the source, an exact match is not possible. In this case, you can first use the Remove Grain effect to clean up the destination and then apply the Match Grain effect to the result to get a perfect match.
The Match Grain effect uses noise sampling as its starting point. Basically, entire frames of new noise are synthesized to match the noise samples. You can modify the noise in many ways before the effect is applied to the new image, such as duplicating the noise from an image but making the noise larger and redder before applying the noise to another image.
The Match Grain effect shares some controls with the Add Grain effect. (See Add Grain effect.)
This effect works with 8-bpc and 16-bpc color.
Compensate for existing noise when matching noise
If you’re trying to match the grain between images with the Match Grain effect, and your destination layer already has its own visible grain, a grain mismatch or grain build-up may occur. To prevent these problems, the Compensate For Existing Noise control extracts a noise model from both the source and the destination and then modifies the noise from the source to account for the noise already present in the destination, before applying it to the destination.
To use this control automatically, set the Compensate For Existing Noise slider to 100%. You can then view the noise samples in the destination layer by choosing Compensation Samples in the Viewing Mode menu. You can also reposition the samples in the destination image by setting Sampling Mode to Manual, which makes the Compensation Sample Points available for manual repositioning.
- Apply the Match Grain effect to the destination layer.
- In the Effect Controls panel, adjust the Compensate For Existing Noise value under the Match Grain effect as needed. The noise in the source layer and the noise in the destination layer are sampled, and their difference is calculated, so that only enough noise to match the destination layer to the source layer is applied to the destination.
- To modify the noise samples, choose Noise Samples from the Viewing Mode menu, change the Sampling > Sample Selection control to Manual, and then expand the Compensation Sample Points. The current value of Number Of Samples determines how many points are available.
- To reposition each sample point, do any of the following:
Drag each sample point in the Composition panel to a new location.
Enter new x and y coordinates adjacent to the sample point under the Compensation Sample Points controls in the Effect Controls panel.
Click the point parameter
for
the Compensation Sample Point in the Effect Controls panel, and
then click where you want to move the point in the Composition panel.
- Choose Final Output from the Viewing Mode control.
Median effect
The Median effect replaces each pixel with a pixel that has the median color value of neighboring pixels with the specified Radius. At low Radius values, this effect is useful for reducing some types of noise. At higher Radius values, this effect gives an image a painterly appearance.
This effect works with 8-bpc and 16-bpc color.
Noise effect
The Noise effect randomly changes pixel values throughout the image.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
- Amount Of Noise
- The amount of noise to add.
- Noise Type
- Use Color Noise adds random values to the red, green, and blue channels individually. Otherwise, the same random value is added to all channels for each pixel.
- Clipping
- Clips color channel values. Deselecting this option causes more apparent noise. This control does not work in a 32-bpc project.
Noise Alpha effect
The Noise Alpha effect adds noise to the alpha channel.
This effect works with 8-bpc color.
- Noise
- The type of noise. Unique Random creates equal amounts of black and white noise. Squared Random creates high-contrast noise. Uniform Animation creates animated noise, and Squared Animation creates animated high-contrast noise.
- Amount
- The magnitude of the noise.
- Original Alpha
- How to apply the noise to the alpha channel:
- Add
- Produces equal amounts of noise in the transparent and opaque areas of the clip.
- Clamp
- Produces noise in the opaque areas only.
- Scale
- Increases the amount of noise proportionate to the level of opacity and produces no noise in 100% transparent areas.
- Edges
- Produces noise only in partially transparent areas, such as the edge of the alpha channel.
- Overflow
- How the effect remaps values that fall outside the grayscale
range of 0-255:
- Clip
- Values above 255 are mapped to 255. Values below 0 are mapped to 0.
- Wrap Back
- Values above 255 or below 0 are reflected back into the 0-255 range. For example, a value of 258 (255+3) is reflected to 252 (255-3), and a value of ‑3 is reflected to 3.
- Wrap
- Values above 255 and below 0 are wrapped back around into the 0-255 range. For example, a value of 258 wraps around to 2, a value of 256 wraps around to 0, and a value of ‑3 wraps around to 253.
- Random Seed
- An input value to the random number generator for the noise. This
control is active only if you choose Uniform Random or Squared Random. To produce flashing noise, animate the Random Seed
control. To create smoothly animated noise, animate the Noise Phase
value.
- Noise Phase
- Specifies the placement of noise. This control is active only if you choose Uniform Animation or Squared Animation.
- Noise Options (Animation)
- How noise is animated.
- Cycle Noise
- Produces a cycle of noise that plays through once in the specified amount of time.
- Cycle
- Specifies the numbers of revolutions of the Noise Phase that the noise cycles through before it repeats (available only when Cycle Noise is selected).
Alter the timing of the Noise Phase keyframes to adjust the speed of the Noise Phase cycles.
To save time animating the Noise Phase
value, use the Cycle Noise option to create a seamless noise loop.
Then, render the layer, and re-import it as a new source footage
item.
Noise HLS effect and Noise HLS Auto effect
The Noise HLS and Noise HLS Auto effects add noise to the hue, lightness, and saturation components of an image. The noise generated by the Noise HLS Auto effect is automatically animated noise; you choose the speed of the animation. To animate the Noise HLS effect, use keyframes or expressions. Controls for these effects are the same except for the Noise Phase or Noise Animation Speed control, which controls noise animation.
These effects work with 8-bpc color.
- Noise
- The type of noise. Uniform produces uniform noise. Squared creates high-contrast noise. Grain produces grainlike noise similar to film grain.
- Hue
- The amount of noise added to hue values.
- Lightness
- The amount of noise added to lightness values.
- Saturation
- The amount of noise added to saturation values.
- Grain Size
- This control is active only for the Grain type of noise.
- Noise Phase (Noise HLS only)
- An input value to the random number generator for the noise. When you set keyframes for Noise Phase, the effect cycles through the phases to create animated noise. Greater value differences between keyframes increase the speed of the noise animation.
- Noise Animation Speed (Noise HLS Auto only)
- The speed of the noise animation. To accelerate or decelerate the noise animation, animate this property.
Remove Grain effect
To remove grain or visual noise, use the Remove Grain effect. This effect uses sophisticated signal processing and statistical estimation techniques in an attempt to restore the image to how it would look without the grain or noise. While many techniques, such as applying a mild Gaussian Blur effect or the Median effect, reduce the visibility of noise in an image, the tradeoff is an unavoidable loss of sharpness and highlights. The Remove Grain effect, in contrast, differentiates fine image detail from grain and noise and preserves the image detail as much as possible.
The Remove Grain effect provides several options to precisely balance the reduction in noise and the amount of sharpness retained in the image. Additionally, the Remove Grain effect can analyze the differences between frames to further improve noise reduction and sharpness; since this process operates over time, it is called temporal filtering.
The Temporal Filtering controls of the Remove Grain effect use a statistical algorithm to blend the current frame with previous and next frames. These controls are especially effective in removing compression artifacts from DV or video footage.
To properly evaluate the results of this filter, the result must be viewed in real time, either with a RAM preview or by viewing a movie rendered to a file.
To increase the speed of the Remove Grain effect
preview, adjust the Remove Grain controls in order in the Effect
Controls panel. Specifically, the most efficient workflow is to
find effective degraining settings first and to adjust the last
three controls last.This effect works with 8-bpc and 16-bpc color.
Remove noise or grain from an image
- Adjust any of the following using the Noise Reduction
Settings controls group:
To adjust the overall amount of noise in the image, adjust the Noise Reduction value.
To adjust the amount of noise on each channel individually, adjust the Red, Green, and Blue Noise Reduction values in the Channel Noise Reduction controls.
The blue channel
often has the most pronounced grain in a chemical film-based image.
Try reducing the noise in only the blue channel to retain all image
detail in the other two channels.
Add temporal filtering to a layer
- Apply the Remove Grain effect to your image.
- Place the Remove Grain preview region over the area of the image that has the most subtle changes from frame to frame or that has the most moving image detail.
- Select Enable in the Temporal Filtering controls.
- Adjust the Amount value to 100%.
- Create a RAM preview of the composition or render and export it.
- If you see unwanted streaking or blurs around moving objects, reduce the Motion Sensitivity value, and then preview or render it again.
- Try the following techniques if you want to improve the
results:
To quickly reduce noise in a movie that has a lot of buzzing noise, set the Noise Reduction value to zero and the Temporal Filtering Amount to 100%, and render the movie.
To speed up previews, apply temporal filtering to your layer after all the settings for a single frame have been adjusted.
To retain effects on a layer and also apply temporal filtering to it, precompose the selected layer (choose Layer > Precompose), and then apply the Remove Grain effect to that layer.
Sharpen an image with Unsharp Mask controls
The Remove Grain effect contains Unsharp Mask controls, which increase the contrast of edges and fine details to help restore some of the sharpness that may have been lost during the grain reduction process.
Do any of the following:Increase the Unsharp Mask controls Amount value to obtain acceptable sharpening without generating undesirable artifacts or bringing back too much grain.
Increase the Threshold value to remove any unwanted artifacts that resulted from the sharpening.
Adjust the Radius to change the area over which Unsharp Mask finds details.
Adjust the Noise Reduction value until the image begins to lose sharpness; then decrease the value a little, and then apply the Unsharp Mask controls to sharpen the image.
Turbulent Noise effect
The Turbulent Noise effect uses Perlin noise to create grayscale noise that you can use for organic-looking backgrounds, displacement maps, and textures, or to simulate things like clouds, fire, lava, steam, flowing water, or vapor.
The Turbulent Noise effect is essentially a modern, higher-performance implementation of the Fractal Noise effect. The Turbulent Noise effect takes less time to render, and it’s easier to use for creating smooth animations. The Turbulent Noise effect also more accurately models turbulent systems, with smaller noise features moving more quickly than larger noise features. The primary reason to use the Fractal Noise effect instead of the Turbulent Noise effect is for the creation of looping animations, since the Turbulent Noise effect doesn’t have Cycle controls.
The Evolution controls create subtle changes in the shape of the noise. Animating these controls results in smooth changes of the noise over time, creating results that resemble, for example, passing clouds or flowing water.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
Controls
- Fractal Type
- The fractal noise is created by generating a grid of random numbers for each noise layer. The Complexity setting specifies the number of noise layers. The Fractal Type setting determines the characteristics of this grid.
- Noise Type
- The type of interpolation to use between the random values in the noise grid.
- Invert
- Inverts the noise. Black areas become white, and white areas become black.
- Contrast
- The default value is 100. Higher values create larger, more sharply defined areas of black and white in the noise, generally revealing less subtle detail. Lower values result in more areas of gray, softening or muting the noise.
- Overflow
- Remaps color values that fall outside the range of 0–1.0,
using one of the following options:
- Clip
- Remaps values so that any value above 1.0 is displayed as pure white, and any value below 0 is displayed as pure black. The Contrast value influences how much of the image falls outside this range. Higher values result in a mostly black and/or white image with less gray area. Therefore, higher contrast settings display less subtle detail. When used as a luma matte, the layer has sharper, better-defined areas of transparency.
- Soft Clamp
- Remaps values on an infinite curve so that all values stay in the range. This option reduces contrast and makes noise appear gray with few areas of pure black or pure white. When used as a luma matte, the layer contains subtle areas of transparency.
- Wrap Back
- Remaps triangularly, so that values above 1.0 or below 0 fall back into the range. This option reveals subtle detail when Contrast is set above 100. When used as a luma matte, the layer reveals more detailed textured areas of transparency.
- Allow HDR Results
- No remapping is performed. Values outside the range of 0-1.0 are preserved.
- Transform
- Settings to rotate, scale, and position the noise layers. The layers appear as if they are at different depths if you select Perspective Offset.
- Complexity
- The number of noise layers that are combined (according to
the Sub Settings) to create the noise. Increasing this number increases
the apparent depth and amount of detail in the noise.Note: Increasing Complexity results in longer rendering times. If appropriate, try reducing the Size rather than increasing Complexity to achieve similar results and avoid longer rendering. A trick to increase apparent complexity without increasing rendering time is to use a negative or very high Contrast or Brightness setting and choose Wrap Back for Overflow.
- Sub Settings
- The noise is generated by combining layers of noise. The
Sub Settings control how this combination occurs and how the properties
of the noise layers are offset from one another. Scaling successive
layers down creates finer details.
- Sub Influence
- How much influence each successive layer has on the combined noise. At 100%, all iterations have the same amount of influence. At 50%, each iteration has half as much influence as the previous iteration. A value of 0% makes the effect appear exactly as if Complexity is 1.
- Sub Scaling
- The scale percentage of a noise layer relative to the previous noise layer.
- Evolution
- Uses progressive revolutions that continue to change the
image with each added revolution. This method is unlike typical
revolutions that refer to a setting on the dial control for which
the result is the same for every multiple of 360°. For Evolution,
the appearance at 0° is different from the appearance at 1 revolution,
which is different from the appearance at 2 revolutions, and so
on.
You can specify how much the noise evolves over a period of time by animating Evolution. The more revolutions within a given amount of time, the more rapidly the noise changes. Large changes in the Evolution value over a short period of time may result in flashing.
- Evolution Options
- Turbulence Factor
- The amount by which the speed of smaller noise features differs from the speed of larger noise features. A value of 0 makes the movement of the noise resemble the noise generated by the Fractal Noise effect, in which smaller noise features move at the same speed as larger noise features. A larger value makes the multiple layers of noise appear to roil in a manner more like that of natural turbulence in a fluid.
- Random Seed
- Sets a random value from which to generate the noise. Animating the Random Seed property results in flashing from one set of noise to another (within that fractal type), which is usually not the result that you want. For smooth animation of noise, animate the Evolution property.
You
can easily create new noise animations by reusing previously created Evolution
cycles and changing only the Random Seed value. Using a new Random Seed
value alters the noise pattern without disturbing the Evolution
animation. - Opacity
- The opacity of the noise.
- Blending Mode
- The blending operation between the noise and the original image.
These blending modes are identical to the ones in the Modes column
in the Timeline panel, with the following exceptions:
- None
- Renders the fractal noise only and does not composite on the original layer.
- Hue
- Renders the fractal noise as hue values instead of grayscale. The Saturation and Lightness of the original layer are maintained. If the original layer is grayscale, nothing happens.
- Saturation
- Renders the fractal noise as saturation values instead of grayscale. The Hue and Lightness of the original layer are maintained. If the original layer is grayscale, nothing happens.
For a description of each blending mode, see Blending mode reference.
