I have a MATLAB variable that is a 3×6 cell array. One of the columns of the cell array holds at most 150-200 small RGB images, like 16×20 pixel size (again, at most). The rest of the columns are:
-
an equal number of labels that are strings of a 3 or 4 characters,
-
an image mask, which is about 350×200
-
3 integers
For some reason saving this object is taking a very long time, or at least for the size of the object. It has already been 10 minutes(which isn’t too bad, but I plan on expanding the size of the object to hold several thousand of those small images) and MATLAB doesn’t seem to be making any progress. In fact, when I open the containing directory of the variable, its size is cycling between 0 bytes to about 120kB. (i.e. it will increase to 120 in steps of 30 or 40 kB, then restart).
Is this normal behavior? Do MATLAB variables always take so long to save? What’s going on here?
Mistake: I’m saving AllData, not my SVM variable. AllData has the same data as the SVM keeper, less the actual SVM itself and one integer.
What particular points of the code would be helpful to show for solving this? The code itself is a few hundred lines and broken up in several functions. What would be important to consider to troubleshoot this? When the variable is created? when it’s saved? The way I create the smaller images?
Hate to be the noob who takes a picture of their desktop. but the machine I’m working has problems taking screenshots. Anyway, here it is
Alldata/curdata are just subsets of the 3×7 array… actually it’s a 3×8, but the last is just an int.
Interesting side point: I interrupted the saving process and the variable seemed to save just fine. I trained a new svm on the saved data and it works just fine. I’d like to not do that in the future though.
Using whos:
Name Size Bytes Class Attributes
AllData 3x6 473300 cell
Image 240x352x3 253440 uint8
RESTOREDEFAULTPATH_EXECUTED 1x1 1 logical
SVMKeeper 3x8 2355638 cell
ans 3x6 892410 cell
curData 3x6 473300 cell
dirpath 1x67 134 char
im 240x352x3 1013760 single
s 1x1 892586 struct
Updates:
1.Does this always happen, or did you only do it once?
-It always happens
2.Does it take the same time when you save it to a different (local) drive?
-I will investigate this more when I get back to that computer
3.How long does it take to save a 500kb matrix to that folder?
-Almost instantaneous
4.And as asked above, what is the function call that you use?
-Code added below
(Image is a rgb image)
MaskedImage(:,:,1)=Image(:,:,1).*Mask;
MaskedImage(:,:,2)=Image(:,:,2).*Mask;
MaskedImage(:,:,3)=Image(:,:,3).*Mask;
MaskedImage=im2single(MaskedImage);
....
(I use some method to create a bounding box around my 16x20 image)
(this is in a loop of that occurs about 100-200 times)
Misfire=input('is this a misfire?','s');
if (strcmpi(Misfire,'yes'))
curImageReal=MaskedImage(j:j+Ybound,i:i+Xbound,:);
Training{curTrainingIndex}=curImageReal; %Training is a cell array of images
Labels{curTrainingIndex}='ncr';
curTrainingIndex=curTrainingIndex+1;
end
(the loop ends)...
SaveAndUpdate=input('Would you like to save this data?(say yes,definitely)','s');
undecided=1;
while(undecided)
if(strcmpi(SaveAndUpdate,'yes,definitely'))
AllData{curSVM,4}=Training;
AllData{curSVM,5}=Labels;
save(strcat(dirpath,'/',TrainingName),'AllData'); <---STUCK HERE
undecided=0;
else
DontSave=input('Im not going to save. Say YESNOSAVE to NOT SAVE','s')
if(strcmpi(DontSave,'yesnosave'))
undecided=0;
else
SaveAndUpdate=input('So... save? (say yes,definitely)','s');
end
end
end
This isn’t a great answer, but it seems that the problem was that I was saving the version of my image after I had converted it to a single. I don’t know why this would cause such a dramatic slowdown (after removing this line of code it worked instantly) so if someone could edit my answer to shed more light on the situation, that would be appreciated.