1 and log refer to logarithms.

In mathematics, logarithm is the inverse of power, just as division is the reciprocal of multiplication, and vice versa. This means that the logarithm of a number is an exponent that must produce another fixed number. In a simple example, the logarithmic count factor in the multiplier.

2.log refers to the Gaussian Laplacian operator.

Laplacian operator is a high-pass filter, which is the sum of the second-order partial derivatives of image gray function in two vertical directions. In the case of discrete digital images, it is sensitive to noise to directly replace the second-order partial derivative with the second-order difference of image gray level, and false edge response often appears when extracting edges.

Introduction to logarithm:

In mathematics, logarithm is the reciprocal of power, just as division is the reciprocal of multiplication, and vice versa. [6]? This means that the logarithm of a number is an exponent that must produce another fixed number (radix).

In a simple example, the logarithmic count factor in the multiplier. More generally, the power operation allows any positive real number to be raised to any power, and always produces positive results, so the logarithm of any two positive real numbers b and x whose b is not equal to 1 can be calculated.

If the x power of a is equal to n (a >; 0, and a≠ 1), then the number x is called the logarithm of n with a base, and it is denoted as x=loga N, where a is called the base of logarithm and n is called a real number.