scripts/local_colmap_and_resize.sh

#!/bin/bash


# Set to 0 if you do not have a GPU.
USE_GPU=0
# Path to a directory `base/` with images in `base/images/`.
DATASET_PATH=$1
# Recommended CAMERA values: OPENCV for perspective, OPENCV_FISHEYE for fisheye.
CAMERA=${2:-OPENCV}


# Run COLMAP.

### Feature extraction

colmap feature_extractor \
    --database_path "$DATASET_PATH"/database.db \
    --image_path "$DATASET_PATH"/images \
    --ImageReader.single_camera 1 \
    --ImageReader.camera_model "$CAMERA" \
    --SiftExtraction.use_gpu "$USE_GPU"


### Feature matching

colmap exhaustive_matcher \
    --database_path "$DATASET_PATH"/database.db \
    --SiftMatching.use_gpu "$USE_GPU"

## Use if your scene has > 500 images
## Replace this path with your own local copy of the file.
## Download from: https://demuc.de/colmap/#download
# VOCABTREE_PATH=/usr/local/google/home/bmild/vocab_tree_flickr100K_words32K.bin
# colmap vocab_tree_matcher \
#     --database_path "$DATASET_PATH"/database.db \
#     --VocabTreeMatching.vocab_tree_path $VOCABTREE_PATH \
#     --SiftMatching.use_gpu "$USE_GPU"


### Bundle adjustment

# The default Mapper tolerance is unnecessarily large,
# decreasing it speeds up bundle adjustment steps.
mkdir -p "$DATASET_PATH"/sparse
colmap mapper \
    --database_path "$DATASET_PATH"/database.db \
    --image_path "$DATASET_PATH"/images \
    --output_path "$DATASET_PATH"/sparse \
    --Mapper.ba_global_function_tolerance=0.000001


### Image undistortion

## Use this if you want to undistort your images into ideal pinhole intrinsics.
# mkdir -p "$DATASET_PATH"/dense
# colmap image_undistorter \
#     --image_path "$DATASET_PATH"/images \
#     --input_path "$DATASET_PATH"/sparse/0 \
#     --output_path "$DATASET_PATH"/dense \
#     --output_type COLMAP

# Resize images.

cp -r "$DATASET_PATH"/images "$DATASET_PATH"/images_2

pushd "$DATASET_PATH"/images_2
ls | xargs -P 8 -I {} mogrify -resize 50% {}
popd

cp -r "$DATASET_PATH"/images "$DATASET_PATH"/images_4

pushd "$DATASET_PATH"/images_4
ls | xargs -P 8 -I {} mogrify -resize 25% {}
popd

cp -r "$DATASET_PATH"/images "$DATASET_PATH"/images_8

pushd "$DATASET_PATH"/images_8
ls | xargs -P 8 -I {} mogrify -resize 12.5% {}
popd