Screenshot Stitcher

1. Take your screenshots
・Scroll through the screen and take screenshots as you go.
・Each screenshot should overlap the next by at least two rows.
・Make sure nothing outside the game window is captured (notifications, taskbars, etc).
・Most scrollable screens are supported, including factor / skill / inheritance / training tabs, finish-order tables, score info, entry lists, and support card lists.

2. Load the screenshots
・Drag and drop, choose files, or paste from the clipboard (Ctrl+V).
・Drag the previews to reorder them; click one to see it full-size.
・You can load multiple characters at once.
・Tap the ✕ on a preview to remove it.

3. Tap Generate
・Takes anywhere from instant to a few seconds depending on how many images you loaded.

4. Save the result
・Tap the output image to switch between full size and fit-to-width.
・Use the JPG / PNG / 📋 buttons to save.
・On iOS, long-press the image to save it to your photo library.
・Reset clears everything so you can start over.

Optional: skill icons (β)
・Adds a small skill icon next to each factor.
・Stat-boosting factors (e.g. scenario factors) show a blue icon.
・If the factor name can't be read clearly, [?] shows instead.
・Higher-resolution screenshots give better results — at least 1500px tall is recommended.
・Skill data provided by U-tools.

Ver1.0: Initial release
Ver1.01: Fixed adjacent-image detection logic
Ver1.02: Added output display size toggle; fixed behavior when multiple close buttons are detected
Ver1.1: Added support for loading from clipboard and copying result to clipboard
Ver1.11: Improved behavior when loading many or high-resolution images
Ver1.12: Fixed so stitching works even when content below the close button isn't visible
Ver1.13: Fixed the result background color not being set
Ver1.2: Added processing progress indicator
Ver1.3: Added header display option; hides scrollbar
Ver1.4: Added support for some non-standard layouts (e.g. other users' Uma Musume)
Ver1.41: Added support for the wide-format images from the Google Play Games version
Ver1.42: Fixed distorted output when loading images of different layouts together
Ver1.43: Tweaked stitching to reduce visible seams
Ver1.44: Provisional support for slightly darker screenshots
Ver1.45: When some images can't be positioned, they're now appended to the end
Ver1.5: Reduced misalignment during stitching
Ver1.51: Tweaked detection so faint close-button outlines are still recognized
Ver1.6: Added Ctrl+V to paste from 📋
Ver1.61: Made close-button detection more robust
Ver1.62: Internal logic tweaks for upcoming features; adjusted adjacency thresholds
Ver2.0: Added skill icon display feature (β). Thanks to U-tools!
Ver2.01: Fine-tuned close-button detection threshold
Ver2.02: Fixed missing icon for Lucky Seven factor
Ver2.1: Added support for finish-order table, Champions Meet score info, and entry list screens
Ver2.11: Added support for race detail screen
Ver3.0: Added support for most scrollable screens
Ver3.1: Added horizontal layout for Champions Meet bulletins
Ver3.11: Improved stitching for screens with bottom-pinned buttons (e.g. Uma Musume list)
Ver3.12: Same Uma Musume on different tabs now placed side-by-side
Ver3.2: For certain layouts, ordering is now determined from the scrollbar position
Ver3.21: Disabled scrollbar-based ordering when scrollbar lengths differ; fixed inconsistent results based on load order; misc fixes
Ver3.22: Updated factor-name position detection
Ver3.23: Skip skill-icon processing on non-factor screens
Ver3.24: Stopped adding ? to blue/red/green factors
Ver3.25: Now errors out before running if findLastIndex isn't available
Ver3.26: Added favicon
Ver3.31: Provisional Steam version support
Ver3.32: Fixed cases where left/right were trimmed too aggressively
Ver3.33: Fixed cases where generic stitching didn't work well
Ver4.01: Translated the site to English
Ver4.02: Fixed the "your browser is too old" warning so it actually shows up when it should
Ver4.03: Internal code cleanup — no change to how the site behaves
Ver4.04: Removed an accidental duplicate setting
Ver4.05: The "stitched by scrollbar position" notice no longer flashes multiple times in a row
Ver4.06: Reduced memory used while figuring out the scroll area
Ver4.07: Reduced memory used while handling unfamiliar screen layouts
Ver4.08: Reduced memory used while resizing and joining images
Ver4.09: Reduced memory used while picking out colored pixels
Ver4.10: Reduced memory used while identifying which screen each screenshot is from
Ver4.11: Reduced memory used while slicing each screenshot into parts
Ver4.12: Fixed a potential crash from cleaning up the same memory twice
Ver4.13: Fixed broken skill-icon detection caused by a memory bug
Ver4.14: Stitching is much faster on large screenshots — replaced slow pixel-by-pixel scanning with bulk reads
Ver4.15: Repeat runs are faster — reference images are now loaded once per visit instead of once per screenshot
Ver4.16: Skill-icon detection is faster — the factor template no longer reloads on every factor
Ver4.17: Grouping screenshots by character is faster — comparison data is reused across pairs
Ver4.18: Skill-icon mode starts almost instantly on later runs instead of reloading the Japanese OCR model every time
Ver4.19: Status messages no longer vanish early when a new one appears right after
Ver4.20: The loading spinner no longer gets stuck if an image fails to load
Ver4.21: Fixed a potential crash when stitching certain layouts that don't have a header
Ver4.22: If stitching fails partway through, the next attempt is no longer affected by leftover state
Ver4.23: Removed an unused setting that was disabled anyway
Ver4.24: Removed about 200 lines of dead code
Ver4.25: Layout matching with masks is faster — fewer redundant color conversions per comparison
Ver4.26: Reset no longer reloads the page — keeps OpenCV, the Japanese OCR model, and templates in memory so the next Generate is fast
Ver4.27: PC/Steam screenshots stitch better — tighter crop, more reliable overlap detection
Ver4.28: Stopped misaligning screenshots that only share a section header but no actual content
Ver4.29: Unmatched screenshots now keep your load order instead of always going to the bottom
Ver4.30: Tighter check on PC/Steam matches to avoid wrong alignments from list rows that look similar but aren't
Ver4.31: No more duplicate rows at the seam between two screenshots
Ver4.32: Drag preview thumbnails to reorder them, or click one to see it full-size
Ver4.33: Fixed PC/Steam overlap detection