| name | tifenke-watermark-remover |
| description | Remove faint gray watermarks from 提分课 course videos by normalizing light backgrounds and the green design palette while retaining yellow headers, green panels, white/black text, red annotations, source dimensions, frame rate, and audio. Use when the user says 提分课去水印, asks to process a 提分课 video like the verified 黄绿保留融合版, or wants a pale watermark merged into white and green backgrounds without preserving exact original colors. |
提分课去水印
Use the verified color-normalization workflow for 提分课 screen-recorded course videos. It makes the pale watermark indistinguishable from the surrounding white or green background.
Workflow
- Work from the original local video, never an already processed export.
- Probe dimensions, frame rate, duration, frame count when available, and audio.
- Inspect frames near the beginning, middle, and end. Check for source green near
0x8AC952, watermark-tinted green near 0x80BC4D, a pale gray watermark on white, yellow headers, black/white text, and possibly red annotations.
- If the palette matches, run
scripts/remove-tifenke-watermark.ps1.
- If green differs materially, sample unobstructed green and watermark-overlaid green. Pass them as
-SourceGreen and -TargetGreen. Test a short clip first.
- Inspect all generated verification frames. Confirm the watermark disappears on light and green areas while content remains legible.
- Report the output path and verification result.
Standard command
powershell -NoProfile -ExecutionPolicy Bypass -File "<skill-dir>\scripts\remove-tifenke-watermark.ps1" -InputPath "<video.mp4>"
Default output: <source-folder>\edit\<source-name>_去水印_黄绿保留融合版.mp4.
Use -Overwrite only when the user explicitly wants to replace an existing export.
Verified transform
color=c=0x80BC4D:s=<width>x<height>:r=<fps>[bg];
[0:v]format=rgba,colorkey=0x8AC952:0.12:0.025[key];
[bg][key]overlay=shortest=1,
lutyuv=y='if(gte(val,214),220,val)',
format=yuv420p
- Unify the source green family into the watermark-like green.
- Flatten luma at or above
214 to 220, merging white and faint gray.
- Encode H.264 using
libx264, CRF 16, preset medium, yuv420p, and faststart.
- Copy original audio without re-encoding.
Quality rules
- Preserve width, height, frame rate, duration, and audio presence.
- Export from the original input.
- Prioritize watermark invisibility and content legibility, not exact color preservation.
- Do not apply the fixed palette blindly to people, photographs, gradients, or a substantially different theme. Inspect and adapt first.
- Treat duration difference over 0.25 seconds, missing audio, dimension mismatch, or frame-count mismatch as failed verification.
- If white text disappears, reduce
-Similarity or -Blend. If green watermark remains, slightly increase -Similarity before changing luma thresholds.
Useful options
-OutputPath "D:\output\result.mp4"
-SourceGreen "0x8AC952" -TargetGreen "0x80BC4D"
-StartSeconds 295 -DurationSeconds 8
-Overwrite
The script prints a JSON summary and creates three JPEG verification frames beside the export in a _验证帧 folder. Inspect them before declaring completion.
