How to rotate all images that have different slant to be in a straight line ?

Hi there. So, hee is my example:-

I have different image, different angle of rotation. So haw can I rotate all images using only 1 code? Right now, I can only rotate 1 signature

function pushbutton2_Callback(hObject, eventdata, handles)
image1= getimage(handles.axes1)
 
bw1=imresize(image1,[128 256])

%binarization 
bw1=im2double(bw1);
bw1 = im2bw(bw1,0.90);

%thinning
BW3=bwmorph(~bw1,'thin',0.9)

J = imrotate(BW3,-8,'bilinear','crop');

 %display result at axes2
 axes(handles.axes2)
 imshow(J)

[darova]

All signatures have the same angle of rotation?

[Najwa Samlan]

No, different signatures has different rotate angle