how to calculate number of zeroes in an image array?

suppose i have an image array for example

1 2 3 1 2 1 1
0 1 2 5 8 7 9
4 7 8 9 2 3 0
0 0 0 1 2 0 0

the above array has 7 zeroes so how to calculate it using a matlab code

Answer 1

[Image Analyst]

Here are two ways:

m=[...
1 2 3 1 2 1 1
0 1 2 5 8 7 9
4 7 8 9 2 3 0
0 0 0 1 2 0 0]

numZeros = numel(m) - nnz(m)
numZeros = sum(sum(m==0))

[Adnan Saify]

thanx for your answer ,can you please explain this code to me ,i mean how it works

[Image Analyst]

numel() gives the number of elements in an array. nnz() gives the number of non-zero numbers. m==0 is a binary map of where zeros are. sum() sums that array column by column. To sum the columns sums, call sum() again. See the help for more information.

[Adnan Saify]

thankyou for explanation,i hope it will work.

[Adnan Saify]

i need one more help ,can we determine number of'0' as well as '1' in an array

[Image Analyst]

I already showed you how to do that - find 0's. For example:

numZeros = sum(sum(m==0))

or in general, to find any integer:

countOfThisNumber = sum(sum(yourArray == yourInteger))

so, to count the 1's, you'd do this:

countOf1s = sum(sum(yourArray == 1))

Of course you can use whatever name for the variables you want. You don't have to use the names I used but I do encourage you to use descriptive names, rather than just single letters, so that your code is maintainable/understandable by others (and you) later, and not just an incomprehensible alphabet soup like we see far too often.