image-crop-focal-pointlisted

# Image Crop Focal Point Estimation Determine a normalized `(x, y)` focal point (or CSS `background-position`) so a specific subject stays visible when an image is cropped to a target aspect ratio different from its source — for a smart-crop pipeline, a CSS `background-size: cover` box, or any "center of interest" crop parameter. ## Why this exists Automatic saliency/attention-based cropping (or a naive `center` position) frequently cuts off heads, faces, or other subjects when the source photo's aspect ratio differs substantially from the target box — e.g. a tall 3:4 portrait shot cropped into a wide 3:2 card, or a wide 3:2 group photo cropped into a 1:1 square thumbnail. Manually picking a focal point fixes it, but the crop math is easy to get wrong by eyeballing, and doing it wrong silently ships a bad crop. This skill gives the exact procedure so it doesn't need to be re-derived (or mis-derived) each time. ## Procedure 1. **View the actual source image file**, not a resized/derivative version, at whatever resolution is convenient. Note the tool's reported original dimensions and the displayed-to-original scale factor if shown (e.g. "original 4284x5712, displayed at 1500x2000, multiply by 2.86") — the *fraction* math below doesn't need the multiplier, but it confirms which dimension is width vs. height. 2. **Check for EXIF rotation before trusting displayed coordinates.** If the image renders sideways or upside-down relative to how it's obviously