Chapter 12, Image Processing Tools
| Image Generation Tools | |
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Chapter 12, Image Processing Tools |
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Use the Transform tools to move, reorient, and animate images.
There are four image transformation tools:
| Tool: | Description: |
| 2D Transform | Apply chains of 2D transformations on images--see 2D Transform Tool. |
| Flip | Flips pixels left-to-right, top-to-bottom, or both--see Flip Tool. |
| Orient | Rotates an image--see Orient Tool. |
| Panner | Repositions an image in the X and Y directions--see Panner Tool. |
The 2D Transform tool lets you apply arbitrary transforms on an image and lets you add camera jitter, motion blur, or stabilizing to the image. You can also move, scale, rotate, and shear images in 2D with high quality filtering as well as concatenate transforms to avoid re-filtering.
The 2D Transform tool has the following parameters:
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| Transform generator | Transform Type and Offset | Transform value editors |
| Use: | To: |
| Transform generator | Create, delete, order, mute, solo and reset transforms. Solo (S) takes precedence over Mute (V) (a transform that's both soloed
and muted is visible) while soloing a transform does not affect the muteness of other transforms, thus soloing a transform
then un-soloing it does not lose state.
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| Transform Type | Set the type of transform. You can choose from 1 point, 2 point, 4 point, or scale, rotation, and translation and set source and destination values, as well as adjust offset parameters for tracking or stabilizing purposes--see Chapter 25, Tracking and Stabilizing. |
| Transform value editors | Set the values of your transforms, you can also use the direct manipulators in the Player to transform the image--see 2D Transforms. |
Add a Transform 2D tool at the desired point in the dependency graph (if one is not already there). One transform is automatically added. You can add additional transforms using the New button.
Use the controls that appear in the UI to the right of the super tool controls or the direct manipulators that appear in the Player. The direct manipulation controls are the same as those found in the Warps--see 2D Transforms.
To shear an image, press the Insert key while the focus is in the player (this toggles the transform manipulator and the pivot manipulator), then using the rotate widget, set your pivot angle.
Press the Insert key again and use the scale widgets to shear the image.
Note: Each transform influences transforms which follow it. The more it influences, the more 'global' it is, or conversely, the fewer it influences, the more 'local' it is. The pivot is independent within each transform.
Controls on the 2D Transform tool Output tab lets you add motion blur, filtering, and cropping to your image.
The Output tab has the following parameters:
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| Use: | To: |
| Motion Blur | Add motion blur to the result image. Motion blur can be on or off; when on, there are controls for shutter speed and offset; the time interval over which the shutter is open is centered at the current frame time by default; the offset can be used to move it elsewhere. |
| Filtering | Filter the output image--see Cropping and Filtering the Output. |
| Crop | Crop the output image--see Crop Tool. |
Note: The following example describes one way to simulate camera jitter using the 2D Transform tool combined with a Noise or Rand expression--see Random Number Functions.
Place a Transform 2D tool at the desired point in the dependency graph (if one is not already there).
Select the 2D Transform tool.
Right-click in the X (or Y) value editor and select Set Expression. The Expresso calculator appears.
Select Random, then Noise, and type the following expression: noise(t*50)*15. This expression can be broken down as follows:
| Where: | Returns: |
| noise (t) | A value between -1 and 1. |
| noise (t * 50) | A value between -1 and 1 and where "50" represents frequency. The larger the value, the longer the frequency of the resulting noise. |
| noise (t * 50) * 100 | Values between -100 and 100, where 100 represents amplitude. |
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Note: You may also want to add motion blur to the output for a more realistic effect.
The Flip tool lets you take an image and flip the pixels left-to-right, top-to-bottom, or both when the Link button is enabled. The default setting is vertical flip.
Drag the Flip tool from the Tools tab to the dependency graph in the Schematic view. The image will be vertically flipped.
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Select the desired flip parameters: Vertical, Horizontal, or both.
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Note: The Flip tool's Vertical and Horizontal attributes are both animatable by setting keyframes or using expressions--see Setting Keys Manually and Validating and Applying the Expression String.
The Orient tool lets you rotate its input by 0, 90, 180, and 270 degrees (with the rotation parameter being an enumeration) and further flip the result vertically and/or horizontally.
The vertical and horizontal directions refer to the image after the rotation has been applied.
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Note: When possible, use this tool in lieu of more general transform tools because no resampling the input image required resulting in no loss of image quality.
The Panner tool lets you reposition the image in both the X and Y directions, as well as to reposition the image using the X and Y offset created when used with Tracker tool data inside an expression--see Validating and Applying the Expression String and About Tracking and Stabilizing.
Drag the Panner tool from the Tools tab to the dependency graph in the Schematic view.
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Select the desired reposition parameters: X, Y, or both, and select the desired offset of the X and Y axes.
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Select the filtering option.
Select the anti-aliasing factor.
Note: The Panner tool's X and Y axes attributes are both animatable by setting keyframes or using expressions--see Setting Keys Manually and Validating and Applying the Expression String.
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