Polar Transform

This function block converts a rectangular (Cartesian) image area into a linear polar representation. Use it to unwrap circular or radial features (for example, to examine rings, wheels, or circular seams) so they become easier to analyze with linear tools.

📥 Inputs

Image Any Input image to be transformed. (socket: input)

Center_X Horizontal coordinate of the transform center. If left empty, the block will use the image center. (socket: input)

Center_Y Vertical coordinate of the transform center. If left empty, the block will use the image center. (socket: input)

Max Radius Maximum radius to use for the transform. If left empty, the block will use a radius that fits the image area. (socket: input)

📤 Outputs

Image Any The resulting linear-polar transformed image. (socket: output)

🕹️ Controls

The block has no separate UI widgets; the three numeric inputs act as parameters you can feed from other blocks or manual inputs:

Center_X Horizontal center used for the polar remap. Adjust to move the transform center left/right.

Center_Y Vertical center used for the polar remap. Adjust to move the transform center up/down.

Max Radius Limits how far from the center the transform reaches. Smaller values crop the radial extent; larger values include more of the image.

⚙️ Running mechanism

When the block runs it reads the provided image and numeric inputs, computes a linear-to-polar remap centered at the specified coordinates, and outputs the unwrapped image. If center coordinates or radius are not provided, the block uses sensible defaults so the transform still runs.

🎯 Features

• Unwraps circular or radial structures into a rectangular view for easier inspection.

• Accepts optional numeric parameters so you can lock the center and radius precisely.

• Works with any image-producing block that outputs image data.

📝 Usage Instructions

1. Provide an image to Image Any input.

2. Optionally feed numbers to Center_X and Center_Y to define the transform center (or leave empty to use the image center).

3. Optionally feed a number to Max Radius to limit radial extent.

4. Use the transformed output from the Image Any output for further analysis or visualization.

💡 Tips and Tricks

• To focus the transform on a specific area, crop first using Image ROI or Image ROI Select then feed the cropped image into this block.

• If your image is very large and you want faster processing, use Image Resize before this block to downscale while preserving the area of interest.

• If the circular feature is rotated, align it first with Rotate Image Angle or Image AutoRotator so the unwrapped result is easier to read.

• After unwrapping, use analysis blocks such as Histogram On Line to inspect intensity profiles along the radial or angular direction.

• To visually inspect results, connect the output to Show Image for an interactive preview during development.

• For object searches around a ring, feed the transformed image to detection blocks like Find Object to simplify locating repeating patterns.

(hint: combine the above blocks to build robust inspection pipelines for circular parts, seals, or ring-shaped textures)

🛠️ Troubleshooting

• If the unwrapped image looks offset or warped, check Center_X and Center_Y and adjust them to the true center of the circular feature.

• If parts of the circle are missing, increase Max Radius or crop the input differently using Image ROI so the entire feature is within the transform radius.

• If output appears stretched or low-detail, try reducing input size with Image Resize or improving capture resolution before the transform.

• If no output appears, confirm the input socket labeled Image Any is receiving valid image data (use Show Image to verify).