how can i create a ROI in image for SIFT features extraction !?

hello, I extracted sift features frome this img ,but i wanna just extract the features in the region of eye and mouth , so how can i eliminate the edge features using ROI

thanks in advance !

Answer 1

[yanqi liu]

clc; clear all; close all;
femDetector1 = vision.CascadeObjectDetector('EyePairBig');
femDetector2 = vision.CascadeObjectDetector('Mouth','UseROI',true);

I = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/769211/image.png');
bboxes = femDetector1(I);
bboxes2 = femDetector2(I,round([1 size(I,1)*2/3 size(I,2)-1 size(I,1)/3]));
I2 = insertObjectAnnotation(I,'rectangle',bboxes,'Eye');   
I2 = insertObjectAnnotation(I2,'rectangle',bboxes2,'Mouth');   

figure
imshow(I2)

[messaoudi nada]

@yanqi liu thanks sir but i didn't ask for eye and mouh detection ,i asked for edge features elimination or are there any way to extract SIFT features in region of interest wich is eye and mouth ! that mean without features detection in edge of img