detectSIFTFeatures only working for uint8

2024 3 19
2 个回答
回答已采纳
更新时间：2024 3 19
1 次查看（30 天）

0 个投票

I = imread('cameraman.tif');
points = detectSIFTFeatures(I);
Gives me heaps of points as expected
I = imread('cameraman.tif');
points = detectSIFTFeatures(double(I));
gives no points. The same zero points retured for anything other than uint8, for every image I've tried. The same behaviour is true for SURF points.
Does anyone have any suggestions?

请先登录，再回答此问题。

 采纳的回答

Udit06
Udit06 2024-3-19
Ran in:

0 个投票

Ran in:
Hi Michael,
If you want to use an image of double data type as input, you should first scale it down to the range [0, 1]. Doing so will give you the similar results that you are getting with uint8 data type. Here is the code for the same.
I = imread('cameraman.tif');
points1 = detectSIFTFeatures(I)
points1 =
274×1 SIFTPoints array with properties: Scale: [274×1 single] Orientation: [274×1 single] Octave: [274×1 int32] Layer: [274×1 int32] Location: [274×2 single] Metric: [274×1 single] Count: 274
I = imread('cameraman.tif');
points2 = detectSIFTFeatures(double(I)/255)
points2 =
274×1 SIFTPoints array with properties: Scale: [274×1 single] Orientation: [274×1 single] Octave: [274×1 int32] Layer: [274×1 int32] Location: [274×2 single] Metric: [274×1 single] Count: 274
You can refer to the following note of the MathWorks documentation for the same.
https://www.mathworks.com/help/matlab/ref/im2double.html#:~:text=input%20pixel%20values.-,Note,-Many%20MATLAB%C2%AE
I hope this helps.

更多回答（1 个）

Qu Cao
Qu Cao 2024-3-19
Ran in:

1 个投票

Ran in:
Use im2double:
I = imread('cameraman.tif');
points = detectSIFTFeatures(im2double(I))
points =
274x1 SIFTPoints array with properties: Scale: [274x1 single] Orientation: [274x1 single] Octave: [274x1 int32] Layer: [274x1 int32] Location: [274x2 single] Metric: [274x1 single] Count: 274

类别

在 帮助中心 和 File Exchange 中查找有关 Point Cloud Processing 的更多信息

产品

版本

R2023b

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by