Feat: masks, zip files, leaner, faster, OPENCV_FULL undistortion (#245)

* Feat: masks, zip files, leaner, faster, OPENCV_FULL undistortion

* Fix scale pruning, downscale counts

* Fix casting

* Use int64_t

* Feat: fused L1+SSIM loss

* Drop --keep-crs, use --center (invert logic)

Merge pull request #243 from pierotofy/winfix

Add Colmap OPENCV_FULL, use C++20

Bump version

Merge pull request #85 from pierotofy/cam

Save cameras.json

Interactive viewer demo

Merge pull request #56 from pierotofy/orient

Preserve scale/orientation of scene input

Update README.md

Merge pull request #43 from pfxuan/empty-cache

Reduce VRAM consumption

Fix OPENCV_DIR type

Update readme