the resolution for one pixel

Hello, I have image in Matlab, how can I know the resolution for one pixel, if every pixel 1 mm or more, I mean how can I measure on the image. Thank you very much

Answer 1

[Jan]

You can't. An image is represented as a 3D RGB array, but there is no information about the resolution - usually.

If you think, that it is possible in theory to determine the resolution, please specify the expression "I have image in Matlab".

Answer 2

[Image Analyst]

You have to measure some known thing in your image, such as a ruler or meter stick. Then calculate the number of pixels per mm, or mm per pixel. Then you have a calibration factor that you can divide or multiply respectively to get your answer in mm.