how to convert array to double

i had made extract to image feature to compare by a snapshot by a webcam but i cant make if statement for this array

660×1 SURFPoints array with properties:

Scale: [660×1 single]

SignOfLaplacian: [660×1 int8]

Orientation: [660×1 single]

Location: [660×2 single]

Metric: [660×1 single]

Count: 660

so i can make if there subtraction = to zero make the if statement else do other statement

[Jan]

"i cant make if statement for this array" - this is not clear. I do not understand this also: "i cant make if statement for this array"

Please edit the question and explain, what your question is.

[saeed ahmed]

ok this is an image i extracted is features and i capture photo by a webcam and get the similar between the two pics if they are the same or not as illustrated in the attactment the left pic is the input image and the right is captured by cam now i wanna put a condition that if they are similiar to each other or have common points it will make a rectangle around this object and here is my code also

clear all
clc
box=imread('Box3.jpg');
c=rgb2gray(box);
boxPoints = detectSURFFeatures(c);
[boxFeatures, box_Points] = extractFeatures(c, boxPoints);
figure,imshow(c);



a=webcam;
a.resolution= '640x480';
Obj=snapshot(a);
b=rgb2gray(Obj)
figure,imshow(b);
scenePoints = detectSURFFeatures(b);
[sceneFeatures, scenePoints] = extractFeatures(b, scenePoints);
%if(x==0)
boxPairs = matchFeatures(boxFeatures, sceneFeatures);
matchedBoxPoints = boxPoints(boxPairs(:, 1), :);
matchedScenePoints = scenePoints(boxPairs(:, 2), :);
[tform, inlierBoxPoints, inlierScenePoints] = ...
    estimateGeometricTransform(matchedBoxPoints, matchedScenePoints, 'affine');

figure;
showMatchedFeatures(c, b, inlierBoxPoints, ...
    inlierScenePoints, 'montage');

diff_im=imsubtract(Obj(:,:,1),rgb2gray(Obj));
diff_im=medfilt2(diff_im,[3,3]);
diff_im=im2bw(diff_im,0.18);
 diff_im=bwareaopen(diff_im,300);
 bw=bwlabel(diff_im,8);
props = regionprops(bw, 'Centroid','Orientation','BoundingBox');
figure, imshow(Obj)
hold on
center=props(1).Centroid;
plot(center(1), center(2), '-m+')
angle = props(1).Orientation
Rec= props(1).BoundingBox
rectangle('Position',Rec,'EdgeColor','r','LineWidth',2)

text(round(center(1))-50, round(center(2))+20, ['The Cenroid','(',...
num2str(round(center(1))), ',' , num2str(round(center(2))), ')'], 'BackgroundColor', [0 1 1]);
text(round(center(1))-50, round(center(2))+45, ['Rotation Angle from right horizontal',' ', num2str(angle)], 'BackgroundColor', [0 1 1]);
%end
x=box_Points

[Jan]

"between the two pics" - there is one image only.

I do not understand the rest of the text. Please use the standard commas and dots to make it easier to read it.

I still do not see, how your code and the explanatipons are related to "how to convert array to double". Please read: TUTORIAL: how to ask a question (on Answers) and get a fast answer