https://github.com/kmkolasinski/fast-bfmatcher

https://github.com/kmkolasinski/fast-bfmatcher

Last synced: 8 days ago
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• Host: GitHub
• URL: https://github.com/kmkolasinski/fast-bfmatcher
• Owner: kmkolasinski
• License: mit
• Created: 2021-12-20T06:54:31.000Z (almost 3 years ago)
• Default Branch: main
• Last Pushed: 2022-04-12T02:23:38.000Z (over 2 years ago)
• Last Synced: 2024-09-30T05:28:51.448Z (about 1 month ago)
• Language: Jupyter Notebook
• Size: 966 KB
• Stars: 6
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# fast-bfmatcher

Faster implementation of the OpenCV BFMatcher(cv2.NORM_L2) matcher for image keypoint

matching



## Usage

* CC stands for Cross-Check

* RT stands for ratio test i.e. Lowe's ratio test proposed in the original SIFT paper

```python

import os

import cv2

# set number of threads for BLIS, must be set 

# before import, cannot be change later

os.environ["BLIS_NUM_THREADS"] = "4"

# running benchmarks

from fast_bfmatcher import FastL2RTBFMatcher, FastL2CCBFMatcher, FastL2RTCCBFMatcher

sift = cv2.SIFT_create()

_, des1 = sift.detectAndCompute(image1, None)

_, des2 = sift.detectAndCompute(image2, None)

fast_matcher_rt = FastL2RTBFMatcher(ratio=0.7)

fast_matcher_cc = FastL2CCBFMatcher() # cross check matcher

fast_matcher_rt_cc = FastL2RTCCBFMatcher(ratio=0.7) # cross check and ratio test

fs_match = fast_matcher_rt.match(des1, des2)

cv_match = fast_matcher_cc.match(des1, des2)

# match contains indices and distances

fs_match.indices, fs_match.distances

```

# Installation

```bash

 # (recommended) to build BLIS on the host machine 

 pip install git+https://github.com/kmkolasinski/fast-bfmatcher

 # to install pip prebuild package

 pip install fast-bfmatcher

```

# Information

* Speed up is achieved thanks to fast [blis](https://github.com/flame/blis) library

* Optimized with SIMD instructions custom C implementations

# Quick command to check speedup

```python

import os

import cv2

# fix number of threads for BLIS, must be set 

# before using this library, cannot be change

# later

os.environ["BLIS_NUM_THREADS"] = "4"

# fix number of threads for numpy

os.environ["OMP_NUM_THREADS"] = "4"

# fix number of threads for OpenCV

cv2.setNumThreads(4) 

import pandas as pd

from fast_bfmatcher.benchmark import benchmark_cc_rt_size_scan

from fast_bfmatcher.benchmark import benchmark_cc_matchers

benchmark_cc_matchers()

# to generate the plot above run this benchmark

metrics = benchmark_cc_rt_size_scan()

df = pd.DataFrame(metrics)

ax = df.set_index("size").plot(lw=2, colormap='jet', marker='.', markersize=10, figsize=(10, 5), fontsize=20)

ax.set_xlabel("Dim")

ax.set_ylabel("Time [ms]")

```

# Building library locally

```bash

python setup.py build_ext --inplace

```

# Testing 

```bash

export BLIS_NUM_THREADS=8;

export OMP_NUM_THREADS=8

pytest -s

```