# \#sift

**URL:** https://forum.opencv.org/tag/sift/198.md

[Latest](https://forum.opencv.org/latest.md) · [Categories](https://forum.opencv.org/categories.md) · [Tags](https://forum.opencv.org/tags.md)

---

## [\[OpenCV.js\] Getting SIFT and FLANN to work](https://forum.opencv.org/t/opencv-js-getting-sift-and-flann-to-work/9987)

<div class="topic-metadata">

**Author:** [@Digizard](https://forum.opencv.org/u/Digizard)\
**Replies:** 7\
**Last updated:** [May 14, 2025, 9:26am UTC](https://forum.opencv.org/t/opencv-js-getting-sift-and-flann-to-work/9987 "2025-05-14T09:26:11Z")

</div>

Hi, all! I’m looking for help on how to use SIFT and FLANN with OpenCV.js. I basically want to translate this code from Python: needle = cv.imread('needle.png', 0) haystack = cv.imread('haystack.png', 0) sift = cv.SIF…

---

## [Currently, Is there no GPU implementation of SIFT?](https://forum.opencv.org/t/currently-is-there-no-gpu-implementation-of-sift/20866)

<div class="topic-metadata">

**Author:** [@samjakar](https://forum.opencv.org/u/samjakar)\
**Replies:** 0\
**Last updated:** [April 22, 2025, 1:49pm UTC](https://forum.opencv.org/t/currently-is-there-no-gpu-implementation-of-sift/20866 "2025-04-22T13:49:53Z")

</div>

Hello all, I am trying to benchmark the perfornmance of computation of SIFT and homography in a CPU implementaion vs on a GPU. I dont think I am finding a GPU implementaion of SIFT. I searched for the current documentat…

---

## [Calculate SIFT keypoints for all given points](https://forum.opencv.org/t/calculate-sift-keypoints-for-all-given-points/12514)

<div class="topic-metadata">

**Author:** [@apo1](https://forum.opencv.org/u/apo1)\
**Replies:** 4\
**Last updated:** [March 24, 2023, 4:04pm UTC](https://forum.opencv.org/t/calculate-sift-keypoints-for-all-given-points/12514 "2023-03-24T16:04:32Z")

</div>

I have a set of 2D points corresponding to the location of pixels in an image. I would like to compute SIFT keypoints and descriptors only for these points but I don’t find the appropriate methods in the online documenta…

---

## [Generating descriptors from keypoints using SIFT](https://forum.opencv.org/t/generating-descriptors-from-keypoints-using-sift/12014)

<div class="topic-metadata">

**Author:** [@derekdoth](https://forum.opencv.org/u/derekdoth)\
**Replies:** 16\
**Last updated:** [February 16, 2023, 6:40pm UTC](https://forum.opencv.org/t/generating-descriptors-from-keypoints-using-sift/12014 "2023-02-16T18:40:54Z")

</div>

I’m attempting to generate descriptors from a set of keypoints for an image of interest using SIFT. Something like this: import cv2 as cv import numpy as np img = np.random.randn(1024,128).astype(np.uint8) keypoints=\[…

---

## [Understanding SIFT descriptor calculation](https://forum.opencv.org/t/understanding-sift-descriptor-calculation/4024)

<div class="topic-metadata">

**Author:** [@thunderwiring](https://forum.opencv.org/u/thunderwiring)\
**Replies:** 0\
**Last updated:** [June 25, 2021, 1:40pm UTC](https://forum.opencv.org/t/understanding-sift-descriptor-calculation/4024 "2021-06-25T13:40:25Z")

</div>

I need to understand how SIFT calculates the descriptors for the keypoints. Intuitively, i understand that it takes each keypoint, calculates the gradients for each pixel in a circular neighborhood of the keypoint. The…