How to calculate the number of grid on the image whose having the outline of the image

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SWAMINATHAN
SWAMINATHAN 2015-9-2
评论： SWAMINATHAN 2015-10-29
This is my input image, and my code is this ->
img = imread('tanjore3.png');
img(10:10:end,:,:) = 0;
img(:,10:10:end,:) = 0;
imshow(img);
i just place a grid on the image
now the partial output of this is shown below. My question is how to calculate the number of grid whose having the outline of the image ?
My output should be Example : OUTPUT=25 grids
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Image Analyst
Image Analyst 2015-9-14
Don't be silly. OF COURSE the starting point of the grid lines has an effect. Just think about it. Just imagine that the whole grid was lowered a few pixels. Then the dip in the 8th grid column would show up in only one grid row, not two.
SWAMINATHAN
SWAMINATHAN 2015-9-15
am very sorry sir if I irritated you or make you tense am a child since am very new to this domain and you are a master If i did anything wrong I apologise, please pardon me but dont punish.

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Guillaume
Guillaume 2015-9-16
编辑：Guillaume 2015-9-16
This is something that is actually very easy to do with the new histcounts2 in 2015b:
img = im2bw(imread('one.png'));
[y, x] = find(~img); %find row and columns of each black pixel
%make sure the grid starts and end outside of the image for histcounts2 to work
gridx = 0 : 50 : size(img, 2)+50; %grid lines position
gridy = 0 : 50 : size(img, 1)+50; %grid lines position
gridcount = nnz(histcounts2(x, y, gridx, gridy))
The output of hiscounts2 (without the nnz) will actually tell you how many black pixels you have in each grid square
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SWAMINATHAN
SWAMINATHAN 2015-10-29
Thank you very much sir , I will be grateful to you. your answer helped me a lot. I want to be stay in touch with you always sir. :-)
SWAMINATHAN
SWAMINATHAN 2015-10-29
Sorry for very late reply sir. one more doubt sir. In Image and Video Processing am working in the area of Facial Expression Recognition and Emotion Detection. For experimental works I used viola jones algorithm for Face & Facial Components detection (Eye, Nose & Lips).
I am struggling in Localization i.e. locating the points on the Facial components. I used a manual method (ROI-Region of Interest) by clicking over an image it will retrieve the Pixel Position Point information.
I want to automate this Process as soon as I gave an input image the number of points localized as shown in the above Image should retrieve those pixel point information.
Please help me regarding this sir

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Walter Roberson
Walter Roberson 2015-9-4
编辑：Walter Roberson 2015-9-4
Let N be the interval between boundaries, in pixels. Then
black_line_detected = blockproc(YourImage, [N, N], @(block) ~all(block.data), 'PadMethod', 1);
detect_count = sum(black_line_detected(:));
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SWAMINATHAN
SWAMINATHAN 2015-9-21
编辑：Walter Roberson 2015-9-21
THIS IS THE CODE I WRITTEN TO COUNT THE GRID BUT ITS GIVING WRONG ANSWERS
A = imread('one.png');%# Load a sample 3-D RGB image
B = im2bw(A);%# Convert RGB image into Black & White
N = 25;%# N is the Grid Spacing
B(1:N:end,:,:) = 0;%# Change every Nth row to black
B(:,1:N:end,:) = 0;%# Change every Nth column to black
imshow(B);%# Display the image
impixelinfo();%# Display the Pixel information of the image
GridCount = 0;%# Initialise the Grid Count = 0
for i = (1:N:546)%# for (i = 1; i<end; i=i+25) where end = 246 the extreme end of x coordinate
for j = (1:N:292)%# for (j = 1; j<end; j=j+25) where end = 246 the extreme end of y coordinate
for x = (i:1:N)%# for (x = 1; x<=25; x++) where 25 is the Grid Spacing
for y = (j:1:N)%# for (y = 1; y<=25; y++) where 25 is the Grid Spacing
if((impixel(B,x,y) == 0))%# if image pixel information of that particular (x,y) coordinate is 0 then
GridCount = GridCount+1;%#Increase the GridCount by 1
end %# end if loop
end %# end y loop
end %# end x loop
end %# end j loop
end %# end i loop
disp(GridCount);%# Display the GridCount of the image

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