No.
There are lots of ways of producing JPEGs with similar visual characteristics but fairly different byte sizes. For example MozJPEG is known to quite efficient, and a tool such as jpegtran can reduce size without changing even a single pixel.
There are lots of ways of producing JPEGs with similar visual characteristics but fairly different byte sizes. For example MozJPEG is known to quite efficient, and a tool such as jpegtran can reduce size without changing even a single pixel.