Compute Histogram for image recognition.

A polynomial is an expression of the form:

a_nx^n + a_{n-1}x^{n-1} + … + a_1x + a_0

where the coefficients a_i are real numbers and x is a variable. The degree of the polynomial is the highest power of x that appears in the expression. For example, the expression

2x^3 + 3x^2 + 5x + 7

is a polynomial of degree 3.

A polynomial function is a function of the form:

f(x) = a_nx^n + a_{n-1}x^{n-1} + … + a_1x + a_0

where the coefficients a_i are real numbers and x is a variable. The degree of the polynomial function is the highest power of x that appears in the expression. For example, the function

f(x) = 2x^3 + 3x^2 + 5x + 7

is a polynomial function of degree 3.