recall and precision for images

I have 80 images in folder ,those images consists of 10 clases

class no
1              Elephants
2              Buses
3              Beach
'
'
'
'10            Roses

I have to find

recall

precision

average recall and precision

I have reduced the size of image to 256x256x3..and i have taken one query image

please help

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

You seem to have explored how to solve the task in an earlier Question, http://www.mathworks.com/matlabcentral/answers/24562-selecting-an-image-from-folder

[kash]

Walter this is the second part of my work

[Walter Roberson]

You have not asked a question here ?

[kash]

walter i have asked a question

I have to find recall,precision,average recall and precision for that image dataset

[Walter Roberson]

That is not a question, it is a statement.

A question looks like, "I found the formula for precision at [...] but I have not been able to figure out the MATLAB equivalent of the 5th symbol of formula B1.7 there; could someone point me to the appropriate documentation page for it?"

Notice the indication of what you have done so far and of what you are stuck on, notice the implication that once that question is answered, that you should be able to work out things further on your own.

Lacking those, someone might decide that your posting rates a "no_question" or "doit4me" tag.

[kash]

yes walter as u said i have formula i tried but could not get the right answer

Precision P=A/B

Recall=A/C

where Ais number of relevant images retrieved

B is total number of images retrieved

Cis to the total number of relevant images in the database

So for each class i have to find recall ,precision and Average recall vs Average precision,please help

[kash]

i have one query image and have extracted 6 relevant images by calculating eculidean ditance

[Walter Roberson]

What is the MATLAB difficulty you are encountering? Are you having difficulty finding the division operator, or do you believe that MATLAB is calculating incorrect division results ?

[kash]

i have 1 query and 6 retrieved imags,..for these i want to know what is

A,B,C..i know it is silly question ,but i am confused what are they ,please help

Answer 1

[Walter Roberson]

For these calculations, you need to (somewhere) have a table that indicates the actual category of each stored image, and you need information about what category the query image belongs to. Then for each of the retrieved images, look up the actual category and see whether it matches the category of the query image; "A" is the number of the 6 images for which the category of the retrieved image was as desired; "B" is the 6 that you matched with the query; "C" is the total number of stored images in the category being queried.

This is a matter of definition, not a MATLAB-specific question.