count white pixels on each column of a binary image

I need to find the number of white pixels in each column and find the pixel position of column with minimum white pixels

Here is my image

I have done the following code,but it finds white pixels in each row.How can I modify this code to get the correct value

counts(size(topHalf,1):-1:1,:) = sum(topHalf == 1,2)

Answer 1

[Guillaume]

It's puzzling why you can't modify your code:

counts = sum(topHalf, 1);  %all you need to change is the ,2 into ,1 to sum along the rows instead of the columns.

Note that I've removed the == 1, since if the image is binary topHalf == 1 is exactly the same as topHalf.

[rahul unnikrishnan]

How to obtain the column with minimum white pixels

[Guillaume]

[~, indexofcolumn] = min(counts)

[rahul unnikrishnan]

I need to find the pixel coordinates at the portion marked.Please suggest a method