Please explain the following line

Its about threshold segmentation.

th=t0+((max(inp(:))+min(inp(:)))./2);

Answer 1

[DGM]

Without any context, all anyone can give is an answer without context.

min(inp(:)) % this is the global minimum of inp
max(inp(:)) % this is the global maximum of inp
((max(inp(:)) + min(inp(:)))./2 % this is the average of the extrema of inp

So then this is the average of the extrema of inp, plus t0 -- whatever that means

th = t0 + ((max(inp(:)) + min(inp(:)))./2);

Answer 2

[Image Analyst]

The stuff between the parentheses is the midpoint of the histogram. My guess is that they have an image with a narrow histogram and they're trying to threshold it a certain number of gray levels above the mean or peak gray level. It might be better to use a triangle threshold, like the attached utility.

[DGM]

Yes, I saw this

https://www.mathworks.com/matlabcentral/answers/1724355-can-somebody-explain-the-following-code