quickstart for primatte chromakey 3...explanation. this quickstart also great for folks who are...

Get started with Primatte 3.0. This step-by-step guide explains how to quickly create a mask.

Quickstart for Primatte Chromakey 3.0

Make masks in minutes.

[ from: Digital Anarchy] f/x tools for revolutionaries

www.digitalanarchy.com

© 2007, digital anarchy : f/x tools for revolutionaries | Primatte 3.0: Make masks in minutes.2

Quickstart Guide for Primatte 3.0

This Quickstart Guide is an overview of the Primatte 3.0 interface and process. Along with our introductory video tutorials, this is a fast way to learn how Primatte works. The plugin is simple to use but its tools are different than Photoshopʼs and therefore need some explanation. This Quickstart also great for folks who are familiar with chromakey software and just need to find the functions they expect.

About this tutorialPrimatte can extract a foreground from any solid color (though blue or green are typically used). To make things simple, we will refer to the background screen color as ʻgreenʼ. For more clarification about specific tools and concepts, please refer to the full Primatte 3.0 manual and watch the video tutorials available at www.digitalanarchy.com.

To follow along, please download this Zip file: www.anarchyunderground.net/tutes/primatte30_quick.zip. This file contains a few Photoshop files. One green screen photograph has been saved out twice as a single layer file and a multi-layer file. You can use either file for this exercise. Thereʼs also an ʻother greenʼ folder containing more photos from the same photoshoot. Weʼll use these photos later in the Quickstart steps.

Table of Contents

Select the subject layer 3Unlock the Background 3Launch Primatte 3.0 plugin 4Approach A: The AutoMask button 4

AutoMask reality check! 5Preview in Mask View 5Approach B: The AutoMask button 6

Clear mask with Reset button 6Step 1 of 3: Select tool 6Step 2 of 3: CleanBG tool 7Step 3 of 3: CleanFG tool 7Keep transparency as gray 7

Preview in Comp View 8

Evaluate the color spill 9A variety of Spill tools 9Check with Front View 10

Try the Spill Sponge 10Use the Spill Minus 11

Toggle Comp options 11Render your mask 11Use AutoMask for Action/Batch 11

Have questions? 12

Primatte Chromakey 3.0 : Quickstart Guide


Select the subject layerOpen up the Photoshop file of your green screen image. Select the layer that contains the subject to be masked.

In the photograph called ʻgreen girl multiple.psdʼ, there are multiple layers. The two bottom layers are textures that will act as new backgrounds once the subject is surrounded by transparent pixels. You want to click to select the topmost layer of the girl against a green screen.

In the photograph called ʻgreen girl single.psdʼ, there is only one layer, that of the girl against a green screen. Obviously… this is the layer that youʼll select. However, first you need to edit that layer to allow your Photoshop file to support transparency. You must do this BEFORE working with Primatte.

Unlock the BackgroundIn the single layer file, that ʻBackgroundʼ layer has a Lock icon. This layer is like a piece of paper thatʼs glued down. You need to un-glue that Background layer for Primatte to work properly.

To do so, in your Photoshop Layers palette, double-click the Background layer. You will get a dialog box; just click ʻOKʼ.

Your layer now reads as ʻLayer 0ʼ instead of ʻBackgroundʼ and does not have a Lock icon. Now your Photoshop layer can support the transparency that Primatte needs. NOTE: You do NOT have to go through this process with a Photoshop file if the green screen layer is not a Background layer.

The ʻgreen girl multiple.psdʼ file.

The ʻgreen girl single.psdʼ file.



Launch Primatte 3.0 pluginOk, now weʼre ready to use Primatte! From Photoshopʼs Filter menu, select Digital Anarchy> Primatte 3.0. Primatte opens up and covers the Photoshop interface. You wonʼt be able to use Photoshopʼs menus and tools until you apply or cancel Primatte.

Masking in Primatte is very easy. Your first approach should be the AutoMask tool, which is new to Primatte 3.0. If that single automated button doesnʼt create the mask you need, then you will do a simple three-step process using the Select, Clean BG and Clean FG tools. Afterwards, depending upon how much color spill is in your original photo, you will use some of the Spill Removal tools to clean up the masked image.

Approach A: The AutoMask button By default, the Select tool is active. But the fastest way to generate a mask is clicking on the AutoMask button. You do NOT click inside the image area; just click the AutoMask button. Primatte will immediately mask your image.

A settings box will appear. Usually, you donʼt need to change the default setting, which is a 40% Radius. If youʼre not getting good results, however, you can make adjustments. Radius controls how much of the background Primatte will get rid of.

The usable Radius range is really between 30% and 80%. Setting Radius too low will result in too much green/blue being left around the edges. Setting it too high will cause fine detail, like hair, to be lost. Once youʼve changed the Radius, Primatte will re-render AutoMask and produce a different key.

AutoMask is chosen

Primatte first opens



If you want to eyeball each image but let AutoMask do most of the work, then checkmark AlwaysOn. If this option is turned on, whenever you load the Primatte interface, AutoMask will automatically be applied to your photo without you doing anything. Primatte does the work and youʼre just checking to make sure everything looks right.

AutoMask reality check!Something to keep in mind is that AutoMask does NOT work on all photos. Itʼs designed to work on head/shoulder and ¾ length shots, and will not work on full length shots. Also, the images need to be shot with excellent chromakey techniques.

One of the ways AutoMask determines the correct color is by analyzing the right, left and top of an image. Itʼs important the green/blue screen covers the entire background. If the wall behind the green screen is showing along the sides or top, youʼll need to crop the image before AutoMask will function correctly.

When AutoMask does work correctly, your photograph will mask immediately without any extra steps. As youʼll see later in this Quickstart Guide, the most powerful use of AutoMask is tied into Batch processing. Run a Batch Action in Photoshop, select a folder full of images, and end up with a folder full of properly masked images.

Preview in Mask View Letʼs look at how our mask has built. By default, Primatte displays in Comp View, which shows a composite of the subject and background.

Letʼs change that preview to Mask View. At top left of the Primatte interface, click on the Mask View button. This opens a grayscale representation of the mask.

The results: AutoMask has done an excellent job! Letʼs look at the breakdown.

• The green screen area is identified as black. Black shows the pixels that are now transparent.

• The subject is identified as white. White shows the pixels that are opaque and fully retained.

• There are some gray values along the edges of our model where her hair becomes wispy. Gray show the pixels that will be retained to some degree.

• Dark gray means the pixels are more transparent (closer to black) and the underlying imagery will be kept to a lesser degree.

• Light gray means the pixels are less transparent (closer to white) and will be kept to a greater degree.

TRANSPARENT

OPAQUE



Approach B: The AutoMask button Suppose AutoMask didnʼt work properly on your photograph? Our sample photo is well shot and therefore pulled a great mask. If the AutoMask button DOESNʼT work to your satisfaction, or if your green screen photo isnʼt a candidate for AutoMask (see ʻuAutoMask reality checkʼ on previous page), then you will move to the second method of masking in Primatte. This is a simple 3-step process.

Clear mask with Reset buttonBefore you redo your mask, you will need to clear out the mask settings currently in Primatte. Thatʼs easy to fix. Just click the Reset button (along the right side) to forget those mask settings and start from scratch.

Step 1 of 3: Select toolFirst, go back to Comp (Composite) View, then click the Select tool. To generate your initial mask in Primatte, click in the green background. Itʼs best to click on a medium tone green. This is Step 1 of 3 in creating a Primatte mask.

You will immediately see a color shift. Thatʼs because Primatte now recognizes green as the color range to delete. Primatte probably hasnʼt designated all of the pixels correctly on the first pass. We can easily fix that.

After Select tool, Comp View After Select tool, Mask View



Step 2 of 3: CleanBG tool To improve your mask, click on the Clean BG (Background) button. This button cleans up any pixels in the green screen that should have been designated as transparent, but simply werenʼt on the first pass.

Switch to Mask View. Click and drag along the areas in the green screen that are white or gray. This tells Primatte to make those pixels transparent. You want all of the green background pixels to be transparent. This is Step 2 of 3 in creating our mask.

Step 3 of 3: CleanFG toolStill in Mask View, letʼs do a similar pass on the foreground subject, our female model. Choose the Clean FG (Foreground) button. Now click and drag along any areas of the foreground object that are not completely white. This is Step 3 of 3 in creating the mask.

Be careful to only click/drag in solid areas of your photograph. Do NOT sample along the edges of your subject. For the Clean FG and Clean BG tools, you must sample areas that do not contain a transparency value.

Keep transparency as grayYou want the subject to preview as white in Mask View with one important exception. Any areas that are meant to be fully or partially transparent (like hair, shadows, glass) should remain gray.

After Clean BG tool, Mask View After CleanFG tool, Mask View

Final results

Next clicks

First clicks



This is the case whether you are using the AutoMask tool or our 3-tool method. To retain gray, you must be careful where you click/drag the Clean FG and Clean BG tools

It is likely that the edges of your subject contain some transparency value. Sampling a transparent area for Primatte to use in building its mask will throw off the color model it is using (which is green vs. all other colors in the image). Therefore, you should always sample from inside or around your subject, NOT along the edges.

Similarly, your photograph may contain interior imagery that is semi-transparent. For instance, your model is wearing a sheer blouse or holding a clear object. (In our example at right, the model is holding a see-through glass bottle.)

In situations where the green screen shows through the subject, you should not let Clean FG or Clean BG touch the areas that contain transparency.

Preview in Comp View Your mask is almost complete! Click on the Comp View button to view a preview of the composite of your masked subject.

• If your Photoshop file contains other layers, your subject may preview against the bottommost layer. For this to happen, the Composite Against Background Layer popup option needs to be turned on (next to the Back View button).

* If your Photoshop file only contains that green screen layer, your subject may preview against a solid color. For this to happen, the Composite Against Color popup option needs to be turned on (next to the Back View button). By default, this is neutral gray. You can change the color of that preview through the popup menuʼs color swatch.

* If your Photoshop file only contains that green screen layer, your subject may preview against a gray-and-white checkerboard. This checkerboard shows transparency and can be turned on/off in Photoshopʼs Preferences> Transparency & Gamut settings.

Shows bottommost layer

Don’t click here either

Don’t click here



Evaluate the color spillNow that the subject is masked, you may see some ʻcolor spillʼ along her edges. Color spill is generated during your photoshoot, as lighting bounces off the green background screen and onto the model.

Spill typically shows up in semi-transparent areas like hair, or shiny areas like patent leather shoes, or along other parts of your subject if the lighting was set up incorrectly. (In our example, the modelʼs blonde hair has a greenish tinge.) That spill can be treated with one or more of Primatteʼs Spill Removal tools. The less spill you have, the more easily itʼs fixed.

A variety of Spill toolsThere are many Spill Removal tools to choose from in Primatte. Each tool works a little differently and the correct tool (or tools) for a particular photograph depends upon how much spill is present and where it appears.

We will briefly cover two of these tools in this Quickstart Guide. For more info about Spill Removal, please watch our Spill Removal tutorial movies at www.digitalanarchy.com/primatte/primatte_tutes.html. You can read detailed descriptions of each tool in the Primatte product manual, also available from that web page.

Shows solid color Shows transparent pixels

Greenish tinge around wispy hair edges



Try the Spill Sponge To remove the extra green in our modelʼs hair, letʼs try out the Spill Sponge tool. This is typically the Spill Removal tool that we try first. The Spill Sponge is very powerful because it has a high threshold; that is, it looks for a wide range of green tones to remove. Select the tool, then click on the primary area tinged with green.

By clicking once or twice with the Spill Sponge, the green spill should be removed. However, if you only have a slight amount of spill, then the Spill Sponge may remove TOO MUCH color. Itʼs possible that the Sponge will overcorrect for green and remove other tones from the rest of your photo.

If too much color is removed, hit the Undo button to go back to your original image. Then try another tool with a lower threshold, like the Spill Minus button.

After Spill Sponge, Comp View, Comp Shows Layer

After Spill Sponge, Comp View, Comp Shows Color

Over-correction with Spill Sponge. The hair is too bright and a little pixelated because color values have shifted. Skin tones have also shifted a little, since they look a little too shiny.

Use Undo button to remove the over-correction.

Check with Front ViewHow can you tell if the tonal values have shifted too much during spill correction? One trick is to use the Front View button. If you toggle between the Front and Comp views, you will be able to detect a difference in color between the masked and original images.



Use the Spill Minus Letʼs try out the Spill Minus tool for this green spill. The Spill Minus tool is a great option when the color spill is too light for Spill Sponge to work effectively. This tool will remove a smaller range of the green. In fact, the way to use the Spill Minus tool is to click/drag multiple times along an area until you see a noticeable shift.

If you go too far with Spill Minus, you can undo in one of two ways. Either click the Undo button or click the Spill Plus button. Both methods will back up as many steps as needed.

Toggle Comp optionsA good way of checking whether your spill is corrected is make use of the Comp Viewʼs options. Toggle between Comp Shows Layer and different color choices for Comp Shows Color. The visual shift in background will help you detect the success of spill removal.

Render your maskYour mask is finished! Just click the Apply button (which looks like a checkmark) at top right of the Primatte screen. This will render the mask into your Photoshop file, deleting the green and leaving your subject surrounded by transparent pixels. Now you can add new layers and composite in a new custom image.

Primatte will remember the last mask that you created. When you reopen Primatte to work on your next photograph, the settings for the previous mask will apply. Either this will be a convenient, fast fix for your next photograph OR the settings will be completely wrong. Thatʼs easy to fix. Just click the Reset button to forget those mask settings and start from scratch.

Use AutoMask for Action/BatchNow that youʼve quickly and successfully created a mask, you can tie Primatte 3.0 into something even more powerful. Primatte fully supports Actions and Batch processes in Photoshop. The real power of the AutoMask tool is its ability to work with group of photographs that were taken under similar lighting and environmental conditions.

This group of photos is perfect for Batching



For use with Actions, you want to checkmark AlwaysOn. When AlwaysOn is turned on, Primatte analyzes each image separately, pulling the best mask for that image. The settings for the previous image are discarded as soon as the new image is loaded.

Once youʼve rendered your Primatte mask, the Primatte interface closes and youʼre back in Photoshop. In Photoshopʼs Action palette, tie Primatteʼs mask settings into an Action by running AutoMask on one photo in the group.

Next, tie that Action into a Batch process. Select a folder full of images, run your Batch Action, and end up with a folder full of properly masked images. This is an extremely powerful workflow and wonderful for people who work with a large volume of photos, like school portraits.

For more info about automating Primatte and photo groups, please check out our tutorials at www.digitalanarchy.com/primatte/primatte_tutes.html. You can also check the Photoshop Help menu to learn more about Actions and Batch processing.

Have questions?We hope youʼve enjoyed this Quickstart Guide, or at least learned something useful. Have questions? Just email [email protected] or call us during regular business hours at (415) 586-8434. Thanks! -The Anarchists


quickstart for primatte chromakey 3...explanation. this quickstart also great for folks who are...

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