ComfyUI Node: Point Preview

Point Preview:

The PointPreview node is designed to facilitate the visual selection of a specific point on an image, which is particularly useful in applications such as lip-syncing or other image-based tracking tasks. This node allows you to interactively choose a point on an image by clicking, which sets the coordinates for further processing by a point tracker. The primary benefit of this node is its ability to provide a visual interface for selecting the starting coordinates, making it easier to ensure accuracy before running more complex tracking algorithms. By offering a preview of the selected point, complete with a crosshair for precision, it enhances the user experience by allowing you to confirm the exact location of interest on the image.

Point Preview Input Parameters:

image

This parameter represents the image on which you want to preview and select a point. It is typically the first frame of a sequence and serves as the canvas for your selection. The image is crucial as it provides the visual context for selecting the point of interest. The tooltip suggests that this is the image you will interact with to set the coordinates.

x

The x parameter specifies the horizontal coordinate of the point you wish to select on the image. It allows you to manually set the x-coordinate, although it is typically set by clicking on the image. The default value is 0, with a minimum of 0 and a maximum of 8192, allowing for a wide range of image sizes. This parameter is essential for pinpointing the exact horizontal location of the point.

y

Similar to the x parameter, the y parameter defines the vertical coordinate of the point on the image. It is also set by clicking on the image, but can be manually adjusted if needed. The default value is 0, with a range from 0 to 8192, accommodating various image dimensions. This parameter is vital for determining the precise vertical position of the point.

crosshair_size

The crosshair_size parameter controls the size of the crosshair arms that appear on the image to indicate the selected point. This visual aid helps in accurately identifying the point's location. The default size is 15, with a minimum of 5 and a maximum of 50, allowing you to adjust the crosshair size based on your preference or the image's resolution. A larger crosshair can be helpful for better visibility, while a smaller one might be preferred for precision.

Point Preview Output Parameters:

preview

The preview output provides an image with the selected point visually marked, typically using a crosshair. This output is crucial as it allows you to verify the accuracy of the point selection before proceeding with further processing. The preview helps ensure that the point is correctly positioned on the image.

x

This output returns the x-coordinate of the selected point. It confirms the horizontal position of the point on the image, which is essential for subsequent tracking or processing tasks.

y

The y output provides the y-coordinate of the selected point, confirming its vertical position on the image. This information is necessary for any further operations that rely on the precise location of the point.

Point Preview Usage Tips:

• Use the click-to-pick interface to accurately select the point on the image, ensuring that the crosshair is positioned exactly where you need it.
• Adjust the crosshair_size parameter to improve visibility or precision based on the image's resolution and your specific needs.

Point Preview Common Errors and Solutions:

Image not displayed

• Explanation: This error might occur if the image input is not correctly provided or is incompatible.
• Solution: Ensure that the image is correctly loaded and is in a compatible format for the node to process.

Coordinates out of bounds

• Explanation: This error can happen if the x or y coordinates exceed the image dimensions.
• Solution: Verify that the coordinates are within the image's width and height limits, and adjust them if necessary.

Crosshair not visible

• Explanation: The crosshair might not be visible if the crosshair_size is set too small or if the image contrast is low.
• Solution: Increase the crosshair_size or enhance the image contrast to make the crosshair more visible.