# Find Reference This function block locates a single instance of a reference image inside a target image, estimates its position and orientation, and returns visual and geometric results that help you inspect or further process the detected object. ## đŸ“Ĩ Inputs `Object Image` The image in which the reference should be located (target image). `Reference Image` The small reference image used to search inside the object image. `Reference Image ROI` Optional shape input to restrict matching to a region inside the reference image (useful to ignore irrelevant parts). ## 📤 Outputs `Result Image` The object image annotated with the detected reference bounding polygon. `Detected Object Image` A perspective-corrected crop of the detected object, transformed to match reference orientation/size. `Keypoints Image` A visualization of feature/keypoint detections on the object image to help verify matches. `Bounding Box` The enclosed rectangle that bounds the detected reference in the object image. `Corner Coordinates` The four polygon corner coordinates of the detected reference area. `Center Position` The center point (x, y) of the detected reference. ## 🕹ī¸ Controls This block does not expose additional widget controls beyond its inputs. Use the `Reference Image ROI` input to limit the reference area when needed. ## 🎨 Features * Visual detection result with polygon overlay for quick verification. * Returns both a perspective-corrected crop and geometric outputs (corners, bounding box, center) for downstream processing. * Accepts an optional ROI on the reference image to focus matching on a sub-region. * Produces a keypoints visualization to help debug matching quality. ## 📝 Usage Instructions 1. Provide the source image to `Object Image` and the template/reference to `Reference Image`. 2. Optionally connect a shape to `Reference Image ROI` to target a specific area inside the reference. 3. Run the scenario — the block will attempt to find the reference and output annotated visuals and geometry. 4. Use the outputs to draw overlays, crop, measure or feed into decision logic. ## 📊 How it runs When executed, the block compares distinctive visual features between the reference and object images, estimates the position and orientation of the best match, and returns a visual annotation plus transformed and numeric geometry outputs that represent the found object. ## 💡 Tips and Tricks * To focus detection on a specific area of the input image, crop beforehand with `Image ROI Select` or `Image ROI` and feed the cropped image into `Object Image`. * If scale or orientation differs significantly between reference and object, try resizing the inputs with `Image Resize` before matching. * Improve robustness under varying lighting by preprocessing with `Adjust Colors`, `Contrast Optimization`, or `Blur` to reduce noise. * Use `Show Image` to preview `Result Image` or `Detected Object Image` interactively while tuning inputs. * Combine the block output with `Draw Detections` or `Draw Result On Image` to overlay textual or rectangular annotations on live images. * If you need a perspective matrix for other measurements, consider following up with `Perspective Transform` using the detected corner coordinates. * When the match returns many false positives, try limiting the reference features using `Reference Image ROI` or apply `Image Threshold` on inputs to simplify textures. (hint) For region-based workflows, use `Get ROI` after detection to extract and forward the detected area to other processing blocks. ## 🛠ī¸ Troubleshooting * No detection found: ensure the reference appears in the object image with sufficient visible texture; try increasing the reference size in the object or use `Image Resize`. * Poor or unstable matches: improve lighting and contrast with `Adjust Colors` or `Contrast Optimization`; reduce noise with `Blur`. * Detection located but warped output looks wrong: validate the corner coordinates using `Show Image` on the `Keypoints Image` and consider restricting the `Reference Image ROI`. * Slow processing on large images: downscale with `Image Resize` before feeding into this block, then map results back to original coordinates if needed.