紅色精靈篩選Sprite Finder
從整晚的錄影或連拍裡，自動找出一閃即逝的紅色精靈Find split-second red sprites in a night of video or burst shots
檔案不會上傳Files never leave your device
影片和照片都在這個分頁裡解碼、分析，伺服器收不到任何檔案。Videos and photos are decoded and analysed inside this tab. Our server never receives them.
掃描結果（事件時間、位置、你的標記）存在這台裝置的瀏覽器裡（IndexedDB），之後可以回來慢慢看；要看畫面時需要重新選擇原始檔案。Scan results (event times, positions, your labels) are kept in this browser (IndexedDB) so you can come back later; to see the frames again you re-select the original file.
RAW 只讀相機內嵌的 JPEG 預覽來分析，速度快很多；同名的 JPEG＋RAW 只算一張。RAW files are analysed through the camera’s embedded JPEG preview, which is much faster; a JPEG + RAW pair counts once.
之前的掃描Previous scans
- 點「畫範圍」，或直接點畫面開始。Press “Draw area”, or just click the picture to start.
- 沿著要偵測的天空邊緣，一個點一個點點下去（至少 3 個點）。範圍要包住雷雨雲上方的天空——精靈出現在雲頂上方。Click point by point around the sky you want to watch (at least 3 points). Include the sky above the storm clouds — sprites appear above the cloud tops.
- 點回第一個點（大圓點）或按 Enter 完成。地面燈光、樹、建築、車燈都要留在範圍外。Click the first (large) point again or press Enter to finish. Keep ground lights, trees, buildings and car lights outside.
- 畫好後可以微調：拖動節點改位置、拖邊線（中間的＋）新增節點、雙擊節點或選取後按 Delete 刪除。Fine-tune afterwards: drag a point to move it, drag an edge (the + in the middle) to add a point, double-click a point or select it and press Delete to remove it.
越短每張越乾淨、但組數越多。疊好後照時間一組一組看；偵測範圍只在勾選「自動偵測輔助」時用來排序，疊圖本身是整個畫面。Shorter = cleaner images but more groups. You then browse them in time order; the detection area is only used for sorting when “Auto-detect assist” is ticked — the stacks show the whole frame.
越大越能抓到小而淡的精靈，但比較慢。廣角鏡頭建議 960。Larger catches smaller, fainter sprites but is slower. Use 960 for wide-angle lenses.
按上面的按鈕從第一組開始，一組一組往下看：→ 或空白鍵下一組、數字鍵 1–7 標記、D 切換「突出變化」（把不動的星空和地景扣掉，淡的現象比較好找）。看過的會打勾，下次會從沒看的那組繼續。Use the button above to go through the groups one by one: → or Space for next, number keys 1–7 to label, D toggles “Changes only” (still sky and landscape removed, faint events stand out). Viewed groups get a tick; next time you continue from the first unviewed one.