Storing the output of "imhist" and apply bhattacharyya distance?

How can I store the output of imhist function in any variable. I have used the variable "infoH" for this purpose, but i cannot obtain required results. I want to get "imhist" output of each video frame. How can I do it?

Secondly, I have to calculate bhattacharyya distance. For this purpose, I have to pass these variable "infoH" (having information of each frame in form of histogram) through this function

vid=VideoReader('xylophone.mp4');
infoH = cell([],1) ;
for numFrames = 1:vid.NumberOfFrames
    thisframe = read(vid);    
    infoH{numFrames}=imhist(thisframe);
    if numFrames>1 && numFrames<vid.NumberOfFrames
         a1=imhist(infoH{1});a2=imhist(infoH{numFrames});
         d(numFrames)=bhattacharyya(a1,a2);
 end
end