- First Steps
- Removing Interlacing
- Sizing Your Images
- High-Definition Formats
- Resolution
This chapter is from the book
This chapter is from the book
This chapter is from the book
Removing Interlacing
Creating the still frame is only the first part of this process. It’s time to open it in Photoshop to finish the process. Most video formats produce images by interlacing fields. For an image of a static object, this isn’t a problem because both fields are identical. When the object is in motion, however, portions of the image will show combing from the interlacing, as in FIGURE 4.6.
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Figure 4.6 Those small horizontal lines radiating off moving objects are caused by interlacing. These need to be removed before you print or post the image.
Notice the shoulder of the figure on the left, or the hat of the figure on the right in particular. If you look closely at the full-size image, you’ll notice the combing caused by interlacing.
You could fix this by deinterlacing the image in Final Cut before you export it, but don’t. Final Cut’s deinterlacing is pretty crude, and the whole image doesn’t need to be processed with the deinterlacing filter, only the portions that show the combing.
A better way to fix this is in Photoshop:
- Select the Lasso tool.
- In the Options bar, set the Feather to something like 10 pixels to soften the edges of your selection.
- With the Lasso tool, loosely draw a selection around the moving portion.
- Choose Filter > Video > De-interlace.
I usually start with the default settings for this filter: Odd field using Interpolation. Sometimes the Even field will produce a better result because of how the object was recorded while it was moving. FIGURE 4.7 shows the selection around the figure: the original combing showing on the left and the filtered figure on the right. Removing interlacing like this allows the rest of the image to be unaffected and left as pristine as digital video can provide.
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Figure 4.7 Note the horizontal interlacing lines at the edges of the hat, or the shoulder in front of the window. These interlace artifacts disappear on the right after the filter is applied.