Mathematica Calculating length from pixel count

[wil3]

Hello. Does anyone know of a fast way of converting pixel count into a length metric (preferably using Mathematica)? I have an imaging program that segments and measures the lengths of objects in an image, but the only parameter that I can extract is pixel count, which then can get converted to length if I measure a ruler using the program.

But if objects are diagonal in the image, then the program will obviously see them take up fewer pixels because they have to cross an extra √(2) in order to get detected. So I can't just multiply the pixel count by a constant ratio, since orientation matters.

A lot of my objects are curved, so this isn't a matter of just measuring orientation and then multiplying by an appropriate factor. I'm sure this problem has been dealt with before, and I could probably flesh out a brute force way of solving this pixel-by-pixel, but there's got to be an easier way to do this.

Thanks much,

wil3

 

[NateD]

One approach you could take is to use image analysis techniques to estimate the length of the objects. For example, you could use edge detection algorithms to find the edges of each object and then measure the length of the detected edges. You can then use this information to calculate the length of the objects. This approach should be more accurate than simply multiplying the pixel count by a constant ratio. You could also use thresholding techniques to separate the objects from the background and then measure their lengths directly. You could also use morphological operations such as erosion and dilation to accurately measure the size of the objects. These techniques should be able to provide more accurate measurements of the objects' lengths compared to just multiplying the pixel count by a constant ratio.