how to detect only specific object

i used feature extracting of object and i want to make If statement to make sure that if this object is not detect dont make any action and here is a pic of my object , if there any other object i want it to ignore

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

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]);

[saeed ahmed]

here is an example i want to ingore no-similar object like that