PFClean: The Workbench
In this tutorial you will learn how to use the Workbench in PFClean. The Workbench is where you can access PFClean’s wide range of high precision, resolution-independent restoration effects. You will learn how to create these effects to fix the defects in the tutorial clips.
– Setting Up the Region of Interest
– Creating Effects / Auto Dirt Fix
– A/B Split
– Fix Scratch
– Manual Dirt / Dust Fix
– Colour Balance
– Edit Mode
– Copying Effects Stacks
– Storing Presets
– Using Presets
To learn this tutorial you will need to download and use the footage below.
01. Setting Up a Project
Follow the instructions in the first Getting Started tutorial to create a project and import the tutorial clips into a Media Bin. Then return to the Workflow Manager, create a Workbench node and connect it to the Media Bin.
02. The Workbench User Interface
Double click on the Workbench node in the Workflow Manager. When you first open the Workbench, you will see the panel at the bottom, showing the current Worklist containing all clips in the node. The first clip in the Worklist is automatically loaded into the Stack Manager and the Cinema when you enter the Workbench. You can work on a different clip by clicking its thumbnail in the Worklist.
The button switches the bottom panel between the Worklist view, and the Workbench’s parameters.
03. Building an Effects Stack
Play through the clip to evaluate the defects we are dealing with. The clip suffers from some very obvious dirt and scratches as well as colour fading. The Workbench provides a range of effects to address different film and video issues. We will have to select the effects suitable for tackling the defects in the clip.
Setting Up the Region of Interest
Before we start working with the effects, we are going to set up a region of interest (ROI), to exclude the blanking on the left-hand side of the clip. Switch to the Workbench parameters and click the ROI button to the left of the clip preview to open the ROI panel.
Adjust the left side of the ROI, shown as a dotted rectangle in the Cinema, by simply dragging it into position. Then click the ROI button again to close the panel.
Creating Effects / Auto Dirt Fix
It’s time to create the first effect. Click the button on the left edge of the Stack Manager to open a menu which lists all available effects. Find the Auto Dirt Fix effect and select it from the menu.
You will see the Auto Dirt Fix effect created as the first, top-most, effect in our stack and the bottom panel will change to show the effect’s parameters. To find out more about how to use the Auto Dirt Fix effect and its parameters, click the button on the left of the effect’s UI to open the effect’s help page in your web browser.
The next step is to adjust the Auto Dirt Fix effect’s parameters to suit the clip. Click the View button to see the dirt the algorithm has detected for the current parameters. As one of the actors in the scene is moving his hand quickly, the first thing we are going to do is to increase the Accuracy of the Motion Analysis from Low to Normal.
Then decrease the Min. Contrast setting from 10.00 to 4.00. Parameters can be adjusted by either typing in new values or dragging left and right with the left mouse button pressed to decrease and increase the value. The Auto Dirt Fix effect is now picking up more dirt, as indicated by the red areas. Deselect the View button to see the fixed frame.
Play through the clip to review the result. The A/B split button provides an easy way to compare the result with the original clip. Simply drag the line along at the rectangle to move it across the frame. Then click the A/B button again to view the cleaned frame.
Next we are going to address the few remaining scratches. Click the + button again and select Fix Scratch from the menu. This has created a second effect below the Auto Dirt Fix. The order of processing is top to bottom and the Fix Scratch effect will work on the result of the Auto Dirt Fix. The active effect is the one that is shown in the Cinema and is highlighted in white.
You can change the active effect, by clicking on this round button next to it , or by using the cursor up and down keys on your keyboard. This will allow you to edit the parameters and controls for that specific effect; the Cinema will show the results of everything down to the active effect in the stack.
You can delete the active effect by clicking and confirming on the trashcan below the + button, but we are not going to do this right now.
We are now going to adjust the Fix Scratch parameters in the same way we did the Auto Dirt Fix. Click the View button to highlight the scratches the effect has detected. To prevent potential artifacts, we want the effect to concentrate on larger scratches, so we set the Min Height to 60. Click View again to see the fixed frame.
Manual Dirt / Dust Fix
Click the playblast button to cache the clip in memory for real time review of the fixes so far. Click the button again or press the Escape key to return to the Workbench.
We notice that there are still some defects left in the clip, for example in frame 12. Since our effects got rid of the majority of issues, we are not going to adjust their parameters, but use a Manual Dirt / Dust Fix effect instead.
Click the + button and create the Manual Dirt / Dust Fix effect. In the effect, click the Rectangle button, then draw a rectangle around the piece of dirt we want to fix (PFClean will analyse the selected area and only fix the pixels of dirt in that area). Repeat for other pieces of dirt you may see in the frame.
Next we are going to address the colour fading in the clip. Click the + button again and select Colour Balance from the menu. We can immediately see the result and no parameter changes are necessary in this particular case.
Notice how when you change frame the unprocessed clip is shown first before being replaced by the processed version. This is a measure to ensure interactivity since the processed frame may take some time to calculate. While that calculation is being preformed the unprocessed clip is shown and the text “Processing…” displayed in the top-left of the Cinema. This behaviour maybe more or less noticeable depending on machine specification, effect stack complexity, internal caching of results and other factors.
Click Play or use Playblast to review the result of our stack. There are still a few specs of dirt in the clip, for example in frame 1. We are going to go back to the Manual Dirt / Dust Fix effect to fix the dirt, while still viewing the result of the Colour Balance in the Cinema. This can be done in Edit mode.
Click the Edit mode button to turn on Edit mode. The Cinema will now continue to show the result of the Colour Balance effect, while we can change the parameters of any of the effects further up the stack.
We can change which effect we want to edit by clicking on the round button next to it . Note that only effects further up the stack from the effect being viewed can be edited, since we would not be able to see the result of any change of parameters of effects further down the stack.
Select the Manual Dirt / Dust Fix effect for editing and draw a rectangle around the piece of dirt to fix it. Then click the Edit mode button again to exit Edit mode.
04. Fixing the Second Clip
It is now time to look at the second clip. Click the button next to the clip preview to jump to the next clip. Upon reviewing the clip, we notice that it suffers from similar defects like the clip we have just worked on. In this case, we can re-use the stack and effects parameters we have just created.
Copying Effects Stacks
Click the button to go back to the first clip, then click the copy button .
This opens a dialog to let you pick the elements to include in the copied stack. We want to include all effects and also the Region Of Interest we have defined, so make sure everything is checked, then click Copy. This will open the worklist overlay at the top of the Cinema. Select the second clip, then click Paste. All the automatic effects like Auto Dirt Fix, Fix Scratch and Colour Balance have now automatically been applied to the new clip; the Manual Dirt / Dust Fix effect was copied in case we find any leftover dirt on this new clip, but all manual fixes which were on the original clip will not be copied to this clip.
Use Playblast to review the fixes in the second clip.
Effects stacks can also be stored more permanently as a preset. Click the button to display the Worklist panel, then click the Save button in the Workbench presets panel to store the current stack as a preset. These presets can be used in other Workbench nodes in the project, or exported to other projects.
To later apply a previously stored preset to all clips in the current worklist select the preset in the Workbench presets panel and click Apply All.