how to find true positives,false positive of an image?

i have given an image.how to find true positives,false positives,true negatives,false negatives?

[Walter Roberson]

You need ground truth, and you need a prediction algorithm

[ramya]

any hint sir of a code bcoz m new to this..i have read papers where it was mentioned..but no idea hw to go for it?

[Walter Roberson]

What is it that needs to be detected in the image?

[ramya]

intensity

[Walter Roberson]

Do you mean that you have images of stellar spectra and you need to analyze the absorption and emission lines in order to try to estimate the inherent brightness of the star based on its stellar class?

[ramya]

suppose if i have this image how to find tp fp tn and fn.

[Walter Roberson]

You can

img = imread('pic.bmp');
pixel_is_white = img > 0;

Your image only contains 0 (black) and 255 (white) (also used for the background).

However, there is no obvious connection between anything in that image and truth or not truth.