Sharpness Match

Usage  |  Controls

The Sharpness Match node can be used to correct for minor sharpness differences between the left and right-eye images in a stereo pair. Sharpness differences may occur because of different focus settings on a camera rig, and can cause visual discomfort when the stereo pair is viewed.

The image below shows a comparison of a stereo pair before and after correction. Compared to the left-eye image, the original right-eye image is out of focus. The image on the right shows the right-eye image after sharpness has been matched to the left eye. Note that very significant focus differences cannot be corrected with this node.

Usage

The Sharpness Match node uses disparity vectors generated by the Disparity Solver node to help correct each frame, and therefore should be placed down-stream from a Disparity Solver node as shown in the following image.

The Sharpness Match node will attempt to match the sharpness from one eye of a stereo pair to the other eye. The Correction mode option controls whether the left eye will be corrected to match the right eye, or vice-versa.

Generally, sharpness differences are most visible around edges in the image. The Edge size and Edge threshold % parameters can be used to control which image edges are sharpened. Decreasing the Edge threshold parameter will mean more image edges are included in the sharpening process, and increasing the Edge size parameter will mean wider edges are sharpened.

Controls

Current Clip: Which of the left or right-eye of the stereo pair is being displayed in the Cinema.

Correction mode: Which of the left or right-eye images will be corrected. Options are Correct Right-Eye to match Left-Eye and Correct Left-Eye to match Right-eye.

Edge size: The size (in pixels) of image edges that are used to match image sharpness. The default value is 5 pixels.

Edge threshold %: The minimum strength of edges that will be sharpened. The default value is 70% and decreasing this will mean more image edges are sharpened.

Detail %: How much detail is restored to the image. Increasing this value will increase the amount of overall detail that is restored to the image. The default value is 10%.

Edit ROI: Allow the region of interest to be adjusted in the Cinema window using the left mouse button.

Show ROI: When this is enabled, the current region of interest will be displayed in the Cinema window.

Show checkerboard: Display a checkerboard image in the Cinema window combining the sharpness matched image from one eye with the input image from the other eye that has been warped using the disparity map. This can be used to evaluate the accuracy of the match using different parameters. Pixels that cannot be compared because of occlusions or missing image data are shown in red.

Apply correction: When this is enabled, the sharpness match will be applied to each frame. This option can be toggled on/off to quickly assess the effectiveness of the match.

Default Keyboard Shortcuts

Keyboard shortcuts can be customised in the Preferences.

Show Checkerboard	Ctrl+C
Apply Correction	Ctrl+A
Next Clip	C