BCC+ Primatte Studio

Category: BCC Key and Blend

Effect Name: BCC+ Primatte Studio

The BCC+ Primatte Studio filter, part of the BCC Color and Blend category, is a chromakeying technology used to extract single-color backgrounds from images or clips, creating a transparency matte to place the foreground on new backgrounds. The core technology behind this filter is the Academy Award nominated Primatte keying algorithm, which was developed by Photron and is licensed by BorisFX.

Surrounding this core algorithm are many features that have been developed by various engineering groups at BorisFX, including the Academy Award winning Mocha masking and planar tracking solution for foreground cleanup and background garbage masking and an AI powered ML trained denoiser with options for reducing compression and camera sensor noise for a cleaner key.

Also included in BCC+ Primatte Studio filter are an array of compositing building blocks to further the creation of a photorealistic composite. Primary and secondary spill control, matte adjustment tools, a 3D layer transformation group, color link background matching, independent color adjustments both globally to the foreground and separately along the edge of the isolated foreground element, light wrap for both edge and spill regions, and a hybrid key option.

Although all of the controls for generating key composites are available from within the host control panel, Primatte Studio also includes a custom FX Editor user interface, with a dual viewpanel and an interactive toolbar, where all of the keying tools are clearly labelled and placed within easy reach. We recommend using the FX Editor custom GUI when generating keys with BCC+ Primatte Studio.

Working with the Filter

FX Editor and Presets

• Use the FX Editor to load or save presets for reuse.
• To load a preset: Open the FX Editor, select a preset from the Presets panel, and click Apply to return to the host application.
• To save a custom preset: While in the FX Editor, click the Create Custom Preset icon in the parameter list, enter a preset name, and click Done. Additionally, a custom preset can be saved from the main menu bar by selecting File->Save Preset.
• To import custom presets from another drive: While in the FX Editor, select File->Import Preset from the main menu bar.

Effect Controls

Compare Mode

The Compare Mode is used to view the filtered result alongside the original source layer. Several split-screen and side-by-side display options are available.

For more information, see Compare Mode.

Quick Start Guide

Begin by setting the background composite layer as appropriate for your host.

Launch the FX Editor (note that the same steps apply when working directly with host-side parameters)

Step 1 – Analyze the Image Clip

Step 2 – Clean-up the Background

Step 3 – Clean-up the Foreground

Step 4 – Spill Suppression

Step 5 – Refine the Matte

Step 6 – Composite the Result

Close the FX Editor and return to the host UI

For in-depth details on each of these steps, please scroll to the bottom of this document.

• View: Displays various intermediate mattes and masks that allow for fine tuning the results of different keying stages.
• View Current Matte: Displays the combined matte output no matter which combination of matte pre and post key operations are currently enabled.

Denoise Group

• Enable: Enables the denoise algorithm functions.
• Model: Allows for the selection of the type of noise the filter will attempt to remove.
• Compression+Noise 3.0: Upated compression artifacts and digital noise removal.
• Camera Noise 3.0: Updated camera noise removal.

• Lock Sample: Locks the key sample for refinement, preventing further auto analysis.
• Auto Analyze: Instructs the filter to build a 3D color model based on the colors in the source clip. The resulting polyhedrons are then manipulated to generate the desired matte result.
• Refine Key: Launches the Refine Key custiom UI to manipulate the matte results.
• Sampling Shape: Determines the shape of the sample area.
• Point: In this mode, as the cursor is dragged over the image, a visible dotted snake trail is generated. The pixels under this snake trail are sampled when adjusting the key properties.
• Rectangle: In this mode, as the cursor is dragged over the image, a marquee shape is generated. The pixels that are contained within the shape are sampled when adjusting the key properties.
• Sampling Mode: Selects the desired sampling operation in the native host UI.
• Manual Sample BG: Use this to manually define the initial key shape with advanced analysis to help automatically adjust for detected foreground colors elsewhere in the image. It is generally recommended to use Auto Analyze instead, but the manual sampling may be useful in non-standard situations such as keying out colors other than blue or green. Every time a Manual Sampling click is made, the key properties are fully reset based upon the new sample color so this is not an additive process, but is just intended to set the base key properties which would then be refined by switching to other sampling modes.
• Manual Sample BG Basic: A completely manual version of the initial core key sampling, similar to the Manual Sample BG described above but without any advanced analysis made to refine the initial key based on colors elsewhere in the image.
• Clean BG Noise: Use this to clean-up any semi transparent pixels in the background.
• Clean FG Noise: Use this to clean-up any semi transparent pixels in the foreground.
• Matte Sponge: Use this to add selected colors to the matte.
• Spill Sponge: Use this to add colors to the spill corrector.
• Make FG Transparent: Use this to bring transparency back into selected foreground colors.
• Restore Detail: Use this to restore fine detail in selected foreground colors that may be lost in the key.
• Spill Plus: Fine tuning control to allow more spill in the selected foreground colors.
• Spill Minus: Fine tuning control to remove more spill from the selected foreground colors.
• Matte Plus: Fine tuning control to increase the density of the selected matte colors.
• Matte Minus: Fine tuning control to reduce the opacity of the selected matte colors.
• Detail Plus: Fine tuning control to restore lost detail in the selected matte colors.
• Detail Minus: Fine tuning control to remove fine details from the selected matte colors.

Adjust Light Group

Helps compensate for very unevenly lit screen colors.When encountering difficulty adapting to a widely varying screen color, enabling the Adjust Light option can help smooth out the unevenly lit screen. However, it is frequently preferable in such situations to use the Garbage Matte section with a dilated Mocha mask to eliminate all but the immediately adjacent background regions.

• Enable: Enables the adjust light option.
• Strength: Sets the strength of the Adjust Light processing.

Spill Group

The Spill parameters control the type and strength of the spill correction applied to the regions identified as spill regions during the initial sampling stages.

• Spill Replace Mode: Determines the method of spill control:
• Complement: Each color identified as spill is nudged toward its natural complement depending on the strength of the spill for that color.
• Solid Color: Each color identified as spill is nudged toward a uniform solid color depending on the strength of the spill for that color.
• Softened Background: Each color identified as spill is nudged toward a color taken from a softened version of the background image at the same location depending on the strength of the spill for that color. Requires the Background layer to be selected (at the bottom of the effect).
• None: Disables the spill replace mode.
• Replace Color: Defines the solid color towards which spill regions are pushed when the Spill Replace Mode is set to Solid Color.
• Amount: Sets the strength of the spill correction. This can be set to 0.0 to completely disable the spill correction while still preserving the new alpha channel from the key.

Secondary Spill Group

The parameters in this group suppress the spill completely from the spill region in the filtered source.

• Enable: Enables the secondary spill corrector.
• Screen Type: Selects the color channel for spill suppression
• Green: Suppresses the green channel in spill regions.
• Blue: Suppresses the blue channel in spill regions.
• Red: Suppresses the red channel in spill regions.
• Auto: Automatically selected the color to suppress in the spill regions.
• Bias: Pushes the spill replacement color toward red (low values) or yellow (high values).
• Bias Fixed Channel: When enabled, bias affects all the color channels at once.
• Amount: Determines the strength of the spill correction. This can be set to 0.0 to completely disable the spill correction while still preserving the new alpha channel from the key.

Matte Adjust Group

The Matte Adjust group controls various post processing operations applied to fine tune the details of the matte.

• Enable: Enables the Matte Refinement group.
• Black Clip: Sets the levels, and pushes pixels that are close to solid black to be completely solid.
• White Clip: Sets the levels, and pushes pixels that are close to solid white to be completely solid.
• Shrink+Grow: Used to globally expand or contract the matte
• Blur: Used as a universal blur for the matte
• Wrap: Softens the matte along the inside edges, folding the matte back in on itself.
• Invert Matte: Inverts the matte.

Edge Cleaner Group

Edge Cleaner provides spatial and temporal control over keyed edges. Edge cleaning makes quick work of compressed green screen footage that displays jittering edges around areas with fine detail such as hair.

• Enable: Enables the Edge Cleaner group.
• Cleaning Radius: Determines the area of included pixels to be cleaned.
• Temporal Smoothing: Enables the smoothing of the filter result over time.
• Alpha Contrast: Sets the contrast between the alpha and non-alpha pixels for sharper resolution.
• Strength: Sets the intensity of the edge cleaning.
• Edge Sensitivity: Sets the discrimination between edge pixels and the overall image. Higher values will increase the sensitivity of edge pixel selection.

Holdout Matte Group

The Holdout Matte controls enable hold back mattes to restore regions that are unintentionally being keyed out such as shiny areas of extreme spill or foreground clothing that too closely matches the screen color. It can also bring back edge regions that are inadvertently being fully or partially keyed when other techniques such as Hybrid mode are not working.

• Source: Determines the source for the holdout mattes
• Off: Completely disable any inside masking.
• Crop: Enable a simple rectangular cropping.
• Mocha Mask: Enable Mocha planar tracking mattes.
• Host Mask: (AE Only) Enable AE host masks.
• Launch Mocha : Opens the mocha planar tracking tool. See mocha help links inside the mocha UI for more details on using mocha.
• Use AE Host Mask: Determines how layer masks are imported into the filter.
• Use All: Uses all masks present on the filter layer.
• Choose Single: Selects a single AE native mask shape. When this option is selected, the Select Host Mask pop-up becomes active and displays a list of the current AE native host mask shapes that are present on that layer. Select a single mask shape from the list to use it.
• Choose by Name: Selects mask shapes based on their naming convention. When this option is selected, the Name Starts With pop-up becomes active and displays a list from which the user can select.
• Select Mask: Selects the AE host layer mask to use.
• Mask Name Starts With: Select ways in which multiple AE masks on the current layer may be selected.
• Anything: Selects all masks regardless of the name.
• Letters A through I: Only masks beginning with the chosen letter are selected.
• Mask: All masks shapes that are named Mask are selected.
• Crop Top-Left x/y: Set the coordinates up the upper-left crop boundary.
• Crop Bottom-Right x/y: Sets the coordinates up the bottom-right crop boundary.
• Feather Mask: Softens the edges of the mask shape.
• Invert Mask: Inverts the mask.
• Mask Apply: Determines whether the inside mask affects just the opacity or both the opacity and spill.
• Opacity Only: Removes any changes to opacity in the foreground regions
• Opacity and Spill: Preserves opacity while preserving the spill correction to avoid any color discontinuities with neighboring pixels

Garbage Matte Group

The Garbage Matte controls enable garbage mattes to remove areas that cannot normally be keyed out since their colors are too far from the main screen color such as boom mics, screen markers, or screen edges. For poorly lit screens with highly uneven color, it can also be useful to use a Mocha mask with dilation to eliminate all but the immediately adjacent background colors.

• Source: Determines the source for the holdout mattes
• Off: Completely disable any inside masking.
• Crop: Enable a simple rectangular cropping.
• Mocha Mask: Enable Mocha planar tracking mattes.
• Host Mask: (AE Only) Enable AE host masks.
• Launch Mocha : Opens the mocha planar tracking tool. See mocha help links inside the mocha UI for more details on using mocha.
• Use AE Host Mask: Determines how layer masks are imported into the filter.
• Use All: Uses all masks present on the filter layer.
• Choose Single: Selects a single AE native mask shape. When this option is selected, the Select Host Mask pop-up becomes active and displays a list of the current AE native host mask shapes that are present on that layer. Select a single mask shape from the list to use it.
• Choose by Name: Selects mask shapes based on their naming convention. When this option is selected, the Name Starts With pop-up becomes active and displays a list from which the user can select.
• Select Mask: Selects the AE host layer mask to use.
• Mask Name Starts With: Select ways in which multiple AE masks on the current layer may be selected.
• Anything: Selects all masks regardless of the name.
• Letters A through I: Only masks beginning with the chosen letter are selected.
• Mask: All masks shapes that are named Mask are selected.
• Crop Top-Left x/y: Set the coordinates up the upper-left crop boundary.
• Crop Bottom-Right x/y: Sets the coordinates up the bottom-right crop boundary.
• Feather Mask: Softens the edges of the mask shape.
• Invert Mask: Inverts the mask.

Transform Group

The Transform group contains a set of controls that can be used to position and scale the foreground image clip in 3D space over the background image.

• Position: Sets the position along the horizontal and vertical plane.
• Position Z: Use to reposition along the Z plane.
• Scale: Scales horizontally and vertically by the same amount.
• Scale X: Scales only along the horizontal plane.
• Scale Y: Scales only along the vertical plane.
• Tumble: Rotates the clip along the center of the vertical axis.
• Spin: Rotates the clip along the center of the horizontal axis.
• Rotate: Rotates the clip along the center of the Z axis.
• Shear X: Skews left and right.
• Shear Y: Skews up and down.
• Filter: Determines the type of blur applied to the FG image.
• Filter Softness: Sets the softness of the blur on the FG image.

The Color Link group is used to blend color from the background plate over the foreground image clip.

• Enable: Enables the color link effect.
• Sample Method: Selects how the color channel is sampled for the effect.
• Average: The mean of each color channel in a region.
• Median: The median approximation of each color channel in a region.
• Brightest: The highest luminance value in a region.
• Darkest: The lowest luminance value in a region.
• Max rgb: The highest value of each color channel in a region.
• Min rgb: The lowest value of each color channel in a region.
• Diffuse color: A blurred overlay of the full source frame.
• Sample Region: Used to select the region in the sample layer that is used for the color link.
• Full Frame: Selects the color or luminance values across the full frame of the sample image.
• Point Radius: Selects the color or luminance values based on a user defined region.
• Center X/Y: Sets the X/Y position of the sample area when Point Radius is selected.
• Radius: Determines the radius of the sample area when Point Radius is selected. Higher values will result in a larger sample area.
• Blur: Blurs the source layer. Only available when the sample method is set to Diffuse Color.
• Opacity: Sets the opacity of the color link effect. Higher values will result in a more opaque effect, utilizing the full range of the sample layer pixels. Lower values will result in a more transparent effect.
• Blend Mode: Used to blend the filtered output to the source image. Blend Modes control the blending of the two images, giving the effects many additional creative possibilities.

Color Correct Group

The Color Correction group provides a range of foreground color correction tools for aid in matching foreground and background colors to create a more convincing final composite. A separate set of correction tools for just the foreground edge is found in the Edge Color Correction group.

• Enable: Enables the color correction controls.
• Hue: Sets the hue of the foreground.
• Saturation: Sets the saturation of the foreground.
• Brightness: Sets the brightness of the foreground.
• Contrast: Sets the contrast of the foreground.
• Gamma: Sets the gamma of the foreground.
• Temperature: Sets the temperature of the foreground. Moving the Temperature slider to the left (negative values) will yield a cooler result, while moving the slider to the right will warm up the foreground.
• Cyan/Magenta: Adds either Cyan or Magenta to the foreground. Dragging the slider to the right makes the foreground more magenta and dragging the slider to the left makes the foreground more cyan.
• Red Gain: Adds or subtracts red from the foreground.
• Green Gain: Adds or subtracts green from the foreground.
• Blue Gain: Adds or subtracts blue from the foreground.

Light Wrap Group

The BCC Light Wrap reflects a background image around the edges of a foreground image to form a border. This creates the illusion that light from the background image is reflected onto the foreground image which in turn creates a more convincing composite by making it appear as if the images were shot in the same environment. To use the Light Wrap feature you must set the Background layer control at the bottom of the effect.

• Enable: Enables the Light Wrap.
• Source: Determines the background plate or a solid color for the wrap.
• Softness: Softens the edges of the border image that is reflected or wrapped.
• Color: Sets the solid color for the wrap.
• Lightness: Sets the lightness value of the reflected/wrapped image. Negative values make the reflection darker and positive values make the reflection lighter.
• Width: Determines the width of the reflection or wrap that is generated. Higher numbers result in a larger border. The following examples show the View menu set to Wrap On Black.
• Blend: Determines the method that is used to composite the border.
• Mix with Original: Blends the original and modified results. Use this parameter to control the effective amount of the light wrap adjustment.

Light Wrap Spill Group

The BCC Light Wrap Spill reflects a background image over the spill regions of a foreground image. This creates the illusion that light from the background image is reflected onto the foreground image which in turn creates a more convincing composite by making it appear as if the images were shot in the same environment. To use the Light Wrap Spill feature you must set the Background layer control at the bottom of the effect.

• Enable: Enables the Light Wrap.
• Source: Determines the background plate or a solid color for the wrap.
• Softness: Softens the edges of the border image that is reflected or wrapped.
• Color: Sets the solid color for the wrap.
• Lightness: Sets the lightness value of the reflected/wrapped image. Negative values make the reflection darker and positive values make the reflection lighter.
• Width: Determines the width of the reflection or wrap that is generated. Higher numbers result in a larger border. The following examples show the View menu set to Wrap On Black.
• Blend: Determines the method that is used to composite the border.
• Mix with Original: Blends the original and modified results. Use this parameter to control the effective amount of the light wrap adjustment.

Edge Color Correction Group

The Edge Color Correction group provides a range of color correction tools applied only to the very edge pixels of the foreground for aid in matching foreground and background colors to create a more convincing final composite. A separate set of correction tools for the overall foreground is found in the Color Correction group.

• Enable: Enables the foreground edge color correction.
• Width: Controls how wide a region along the matte edge is affected by the edge color correction.
• Hue: Sets the hue of the edge.
• Saturation: Sets the saturation of the edge.
• Brightness: Sets the brightness of the edge.
• Contrast: Sets the contrast of the edge.
• Gamma: Sets the gamma of the edge.
• Temperature: Sets the temperature of the edge. Moving the Temperature slider to the left (negative values) will yield a cooler result, while moving the slider to the right will warm up the edge.
• Cyan/Magenta: Adds either Cyan or Magenta to the edge. Dragging the slider to the right makes the edge more magenta and dragging the slider to the left makes the edge more cyan.
• Red Gain: Adds or subtracts red from the edge.
• Green Gain: Adds or subtracts green from the edge.
• Blue Gain: Adds or subtracts blue from the edge.

Advanced group

The Advanced group contains specialized controls which are generally only needed in cases where the basic keying controls are insufficient.

• Hybrid Enable: Enables the special Hybrid keying mode which effectively performs two separate keys and then combines the results to enable preserving good edge quality while still avoiding holes in similarly colored foreground regions. See the Workflow Guide, Step 3 (Clean-up the Foreground) for more details on usage.
• Hybrid Blur: Controls the size of the blur used prior to the erosion of the secondary key when using the Hybrid keying approach. Larger blur amounts allow larger erosion which prevents the foreground cleanup from damaging the edge quality, but which then limits the hybrid mode’s ability to protect foreground regions that are near the edge.
• Hybrid Erode: Controls the depth of the edge erosion (shrinking) of the secondary key when using the Hybrid keying approach. Larger erosion amounts allow more shrinking which prevents the foreground cleanup on the secondary key from damaging the edge quality, but which then limits the hybrid modes ability to protect foreground regions that are near the edge.
• BG Color – KF Only: This parameter can be keyframed to adjust the “center” key color in cases where the screen color/lighting changes significantly over time. The overall shape of the 3D key sampling is preserved, but this shape is repositioned in color space to account for the changing central key color.
• Background: Specify the background layer that will be used for the final composite. This must be set when either the Spill Replace Mode is set to Softenened BG or when the Light Wrap group is enabled.

Detailed steps for using Primatte Studio to generate a key

Step 1 – Analyze the Image Clip

After applying the BCC+ Primatte Studio filter to a source clip, the first step should always be to click the Auto-Analyze button so that Primatte can auto-compute the best starting point for the key. Once the initial target for the key has been set, we are free to modify and refine the result. You can find the Auto Analyze button both in the filter’s control panel or at the top of the Primatte Studio FX Editor.

Generally speaking, Primatte will produce a very good starting point using auto-analysis. The auto-analysis mode uses advanced image analysis tools to identify blue/green background colors, estimate foreground color properties, and then generate an initial key which is ready for fine tuning as necessary. The auto-analysis tool should be thought of as a way to quickly dial in the key, but it does not in any way limit the tweakability or quality of the final key. It is not a “dumbed down” approach, but rather the recommended starting point for even the most sophisticated users. Think of it as a short cut to jump start the sampling process that would otherwise need to be done from scratch. In rare situations where the Auto-Analysis does not provide a good starting point, such as when keying colors other than blue or green, you can bypass auto-analysis and manually sample the background by setting the Sampling Mode to Manual Sample BG or Manual Sample BG Basic and then clicking and dragging over the background region of the image in the viewer. Sampling the background is a process that needs only to be done once – sampling multiple areas will not produce an additive result. Each time you Auto-Analyze or use the Manual Sample BG or Manual Sample BG Basic modes it resets the “center” key properties.

Adjust Light

If the background of the clip that you are working with has a lot of variance in the lighting, you can enable the Adjust Light option. This feature attempts to even out the lighting of the background, which often helps when struggling to key out uneven background lighting. However, a great alternative in such situations is to use the Garbage Matte section with a dilated Mocha mask to eliminate all but the immediately adjacent background regions.

Denoise

Another helpful feature in Primatte Studio for refining the background selection is the AI / ML Denoise tool. Should you find that you’re working with a source clip that has a lot of grain, compression or camera sensor artifacts that are being picked up by the keyer, this can be reduced by enabling the Denoise feature and selecting the appropriate model from the pop-up list.

FX Editor Split Viewer / Compare Mode

If working in the FX Editor GUI, the next step is to

The Compare mode, which is located at the top of the filters control panel has an independent split-view option, which in this case will enable us to view the final matte we are generating on one side of the viewer while also seeing the matte status on the other side. This will help while we fine tune the result as the matte status will display very clearly where unwanted semi-transparent pixels exist in both the foreground and background.

Step 2 – Clean-up the Background

After using Auto-Analyze, the filter will automatically switch the Primatte sampling mode to Clean BG Noise. In the Matte Status view, click and drag over any grey pixels in the background to make them fully transparent. Sometimes it’s easier to use the rectangle / marquee select mode for this clean-up work and you can select this option by choosing it from the Sampling Shape menu or directly from the toolbar. Continue to click and drag over any grey pixels in the background until it is solid black or as close to black as possible without eroding the foreground key. Remember, we can always use the Matte Cleanup controls to further remove transparency from the background and / or the integrated mocha background masking tool to generate animated garbage masks to remove unwanted background elements such as props, boom mics etc.

Step 3 – Clean-up the Foreground

After you clean-up the background the next step is to clean the foreground. To do this, select Clean FG Noise, either from the filter control panel or from the toolbar and again, click and drag over any grey pixels in the foreground until they are solid white in the Final Matte or Matte Status preview modes.

Sometimes images will contain foreground colors that are very close to colors along the matte boundary. For example shiny objects in the foreground (such as earrings) or foreground clothing elements might match a edge colors so closely that it is difficult to clean these foreground regions without damaging the smoothness of the matte edge. There are two main solutions to this problem:

• Use integrated mocha masking in the Holdout Matte group (or optionally host masks in AE) to generate an animated “Inside Mask” which will allow the foreground element to remain fully opaque – either with or without spill correction.
• Enable the Hybrid keying mode to allow the creation of two separate mattes which are merged to create a final matte. One matte will maintain smooth, high quality edges while the other matte will ensure that interior foreground regions are fully preserved. When using the Hybid approach, first dial in a high quality edge matte by sampling the foreground and background as usual in steps 1-3, but without worrying about preserving the problematic foreground regions. The goal in this first phase is to get the edges right. Once satisfied with the edges, you then proceed to phase 2 by turning on the Hybrid Enable option in the Advanced parameter group. Now use the Foreground Cleanup tools to fully restore the problematic foreground regions which effectively creates a second matte which is focused on the foreground completeness rather than the edge quality. Lastly you can tweak the blending the two hybrid mattes by adjusting the Hybrid Blur and Hybrid Erode parameters as necessary.

Step 4 – Spill Suppression

By this stage, you should have a very good key so we no longer need to view the Matte Status and this view can be switched to Final Composite. It helps to keep both the Final Matte and Final Composite views visible in the Compare Mode settings as the next stage is to eliminate as much as possible any background spill that was not handled automatically by the Primatte auto-compute function so for now we’ll leave the Compare Mode enabled.

Start by switching the Sampling mode to Spill Sponge. You may find that it’s easier to attenuate the background spill using the Point Shape instead of the Rectangle Shape. With the Point Shape selected, click and drag in the foreground image where you clearly see that the background key color is spilling over onto the foreground. Usually a few clicks is all that is necessary to remove the spill. Keep in mind that you can use undo to step back through the clicks so if you find have gone too far with spill suppression you can use the usual undo shortcuts (CMD/CTRL + Z) to step back or forward through the changes. [Note to Avid Users – due to host-side limitations, the keyboard shortcuts for undo/redo do not work after sampling in Avid until you click on another window outside of the preview window, at which time they then work normally.]

Sometimes, after working with the Spill Sponge, you may find that you need a finer level of control to tune the level of spill in the image. To do this use the Spill + (plus) and Spill – (minus) options, which can be found in the Sampling Mode pop-up of the filters Control Panel and also in the toolbar. With Spill – (minus) Primatte will increase the amount of spill that is being removed from the image with each successive click. With Spill + (plus) Primatte will decrease the amount of spill that is being removed from the image with each successive click. Please keep in mind that these controls will adjust the spill levels by very fine amounts so you may have to make several clicks on the image to produce a visible change.

Once the spill regions have been isolated using the above sampling techniques, the Spill parameter group offers additional controls for fine tuning the type of spill color correction applied. Depending on the individual shot, it can help to change the Spill Replace mode in this group to either Solid Color or Softened Background. If you choose the Solid Color option, you can define the color that is used via the color chip. If you choose the Background option, you must the background layer in the Background input pop-up, which is located at the bottom of the filter. [Pro Tip – you can visualize which areas of the image are receiving spill correction by changing the Spill Replace Mode to Solid Color and temporarily setting an extreme replacement color such as bright yellow or magenta.] The overall strength of the spill correction can be adjusted with the Spill Replace Amount control.

Step 5 – Refining the Matte

After spill suppression is complete, you can fine tune the semi-transparent edge of the foreground to make it either more transparent or more opaque. Use the Matte + (plus) and Matte – (minus) functions to restore transparency or opacity to the foreground. Just like the aforementioned Spill + / – controls, this fine-tuning function adjusts the matte by small increments.

Sometimes you may find it necessary to further enhance the matte to remove areas in the background that are beyond the range of the keying algorithm due to severely uneven background lighting, marks on the background screen, extreme spill, noise, or other problems in the shot.

An example of this may be dark marks on the floor of a green / blue screen and in this example the best option is to utilize the controls in the Matte Refinement section. Soften Matte, Shrink (Black Level), and Grow (White Level) can be used in conjunction with each other to help suppress unwanted alpha in background regions, to fill unwanted holes in foreground regions, or to gently soften the matte edges.

Another example of this may be where props or other unwanted items, such as boom mics etc, need to be removed from the scene. This is best handled via the use of garbage masks. Primatte Studio includes independent foreground and background garbage mask tools, including the integrated mocha feature which can be used to generate animated spline shapes that can be tracked automatically using the mocha planar tracker. When using this filter in the After Effects host, you may also use animated or static host native spline mask shapes directly from within the filter.

Step 6 – Compositing the Result

With the work to generate a solid key complete, the final step in the process is to composite the keyed foreground over a replacement background. Many times, the foreground element will have differences in color and lighting as compared to the background element against which it is being composited. To achieve a more photorealistic composite, the keyed foreground can be color corrected to blend in better with the background.

The Color Correction group in BCC Primate Studio includes a wide array of sophisticated color correction tools, which should provide a wide range of control over the color of the foreground element. Along with the familiar Saturation, Brightness, Contrast and Gamma controls, there are also controls to adjust the Temperature and Tint of the shot. Moving the Temperature slider to the left (negative values) will yield a cooler result, while moving the slider to the right will warm up the shot. Moving the Tint slider to the left (negative values) will add a green tint, while moving the slider to the right will add a magenta tint.

There are independent controls in the Primatte Studio control panel for both global adjustment of the color of the foreground and adjustment of the color along the edges of the foreground. Each of these groups operate independently and offer the same degree of control over the color for global correction and edge correction.

Sometimes, to complete the composite, it can help to blend some of the background image over the edges of the foreground and this can be done from within the filter via the integrated Light Wrap option. Enable Light Wrap, set the background layer in the Background pop-up selector and then tweak the controls in the Light Wrap group to taste. Use the Mix With Original control to blend back the Light Wrap with the foreground – a setting of 50 is often a good place to start. The Apply Mode pop-up can be used to further enhance the composite – the default blending mode is Lighten but sometimes it may help to select one of the other modes, such as Add, Screen, Overlay or Soft Light.