Wire Removal Workflow for Camera Movement CS5
POSTED IN Tutorials and Findings January 14, 2011
There are many, many ways to remove wires and rigging used in animation from a scene where the camera never moves. This tutorial will guide you through the workflow studio.pebble has constructed using Adobe CS5, which we currently are utilizing for the recent stop-motion production for Oh Buggy T-Shirts. There may be other ways of using the innumerable amount of tools (some free or inexpensive, and some very expensive) which have been designed for removing unwanted artifacts from a still image destined to be a motion picture. This is not only the most economical, but also the fastest way we have discovered so far.
This tutorial presupposes you have an understanding of RAW images and importing them into Adobe applications on the OSX platform. Since we are using the animation capture software Dragon and the Canon 5D MKII for principal photography the first part is geared towards converting the Canon Raw Image- or “.cr2″ file into a .”dng” file which will be understandable for the Adobe systems.
If you have a good understanding of your file workflow already and just want the quick how-to for wire removal, you may want to skip down to #4.
- Open Adobe Lightroom. At the top right select the “Library” button. At the bottom of the left hand side file menu you will see an “Import” button. Click this to open up the Import window. At the top of the new window are some options for importing. Select a source from the “Source” box and the multiple photos from a cr2 folder . You can simply select the first cr2 file in the folder and Lightroom will add the rest of images which you can then select in the library’s interface. In this case it will be a specific folder created by Dragon Software when you start a new take. The file name will end in _X1. [Note- there may be jpeg reference photos in the same folder, but you don't have to worry about clicking only the cr2 files. Lightroom will select only the cr2 files when it imports them.] Then click “Copy as DNG”. DNG’s are RAW files with a different extension that isn’t dedicated to, in this case, just Canon software. Copying the photos is very important as you don’t want to simply “move the files” and overwrite the original RAW file with the changes you are making in Lightroom. In the bottom right select “Import.” Choose a new folder for the image files you will be manipulating. Then “Save.”
- In Lightroom we are cropping the image in and rotating it to match previous takes. You can do this with the first photo imported and then copy and paste all of the settings and adjustments made in this photo to all other photographs you have imported.
- When you go to export all of your images from Lightroom to a file where they will be kept for use in Photoshop and After Effects you’ll be given several option in Lightroom of different extensions you would like to export it as. Click the “Export” button in the bottom left. An export settings window appears. In this case, since we have made changed to the RAW files in Lightroom we need to select the “Export as a DNG” under the “File Settings.” Make sure your image size is locked in the dialogue box and select a folder to export all of the new images to. Hit “Export.” You’ll also notice the RAW Window box which is used for certain corrections when you import and export the footage from Lightroom into Photoshop. Make sure to apply all of the Metedata used in Lightroom, to the file when opening it in Photoshop.
- In Photoshop, open the first image in the folder.
In this case it is a tree with lots of monofilament that the yarn “leaves” will be passing over. Since the wires are straight the process is simplified quite a bit. Follow this simple and amazing tutorial on using the “Content Aware Spot Brush Healer in Photoshop” which is a new feature in CS5. http://av.adobe.com/russellbrown/CS5HealingBrushWires_SM.mov - Don’t worry about the path part of this tutorial. Since the camera moves between each frame, each frame will have to be separately painted out. So, following the tutorial: We use the Spot Healing Brush in Photoshop with “Content Aware” selected from the top menu and selecting a point and then shift+clicking on the next point we can start see the wires disappear. 
Make sure to have the brush as small as possible. Larger brushes will sample more of the area around it and depending on how busy certain areas of the image are it may be difficult to get a new, clean image from the tool. In some case as with the wire going through the cloud in the foreground you may want to draw the line by hand so it looks more natural and blends better. - One main problem arises from doing this all by hand. When you paint out these wires by hand they look great from frame to frame. However, since they will be strung together at 24fps, not being absolutely precise in the placement of the painted out areas will cause areas with a lot of detail, like the trunk of this tree to appear to be strobing, revealing the wire removal job we worked hard to make look as clean as possible.
- There is another quick fix for this in CS5. It’s in After Effects. A plugin called CC Simple Wire Removal. It’s a free Plugin that comes with After Effects. It’s not the best wire removal tool out there, but with Photoshop taking care of the bulk of the wire removal for us, it suits our needs well. The purpose of using this tool instead of the more powerful Photoshop tool is that it can be Key Framed and quickly so that any movement of the wire removal lines in the frame are consistent and accurate and more importantly, follow a path that will reduce any strobing.
- So, we select our file to be imported into After Effects. Select the first one in the new .dng folder created earlier in Lightroom that now have the correction applied from Photoshop to them. If all the other corrected .dng files are still in the same folder After Effects will automatically include all of the photos into the sequence. Drag the icon of your project down into the “composition panel” in After Effects. Over in on the right side in the “Effects” bin find “CC Easy Wire Removal” in the “Keying” folder. Drag it over to the composition. Select the target for Point A and place it at one end of the wire. Do the same with Point B and place it at the other end. [Note: Though it may be one wire that is going across the screen, sometimes it is not only, easier but cleaner to add as many "Wire Removal" lines as you feel is necessary to create a clean removal. Be careful to not over do it or you will interfere with the image, distorting it too much.]
- You’ll notice that nothing appears to be happening when you move the point over the wire. In the Effects box in the Project panel, or in the composition panel turn the size of the “Thickness” up till you see some change and until it fits just over the wire. You may notice a line down the middle of this mask you have created. Below the “Thickness” is a parameter called “Mirror.” Turn this up until the line in the middle smooths out. In this same window you’ll notice alarm clocks. These are for Key Framing. It is very important that you have selected. Otherwise any changes you make from frame to frame will not be recorded.
Select all of them and After Effects will record the selection and keep it throughout the editing project. - So you found a good mask size and you’re happy with how it’s turned out but you’ve noticed a small artifact at the point when the mask leaves the screen. When the wire exits the frame at an angle, the tool will leave a small distortion that is nearly impossible to fix in After Effects alone. The quickest solution: I go back to Photoshop and take the same file (the one where I removed all the wires except for the one running down the trunk which I am now trying to mask and key-frame out in After Effects). In Photoshop, at the point where the wire exits the frame I use a clone stamp tool, or a spot
healing brush tool, or in this case- a patch tool and I remove just the bottom portion enough so that when I take it back into After Effects the mask from CC Wire Removal won’t distort the edge of frame anymore. When you take it back into After Effects and readjust the wire mask, you’ll see that it makes a pretty seamless photo sequence. - After this you can choose the work to match the editing software that you are using. You can make a seamless link to Adobe Premiere Pro, or you can render the sequence out to a lossless .mov file that can be imported immediately into Final Cut Pro without having to add the extra step of exporting the sequence from Premiere as an XML and then sending that to Final Cut Pro.
So there it is. Wire Removal for Camera Movement. It can be tedious, but the results you get for such a dynamic sequence is certainly worth it. Here the result of the first 50 frames of our tree dolly/ crane shot using this technique (coming soon).
