Fill-a-pix is a logic puzzle game similar to Pic-a-Pix (aka Logic art) and Minesweeper. An example starting board is shown below on the left with the completed board shown to its right. Each number in the board indicates how many surrounding cells, including itself, are to be filled in. There are (up to) nine total cells associated with each number: four immediately adjacent (up, down, left, and right), four diagonally adjacent (one touching each corner), and the central cell (where the number is located).

Based on this logic, all 0's and 9's are determinant, as all nine cells are either empty or filled, respectively, for these numbers. Also, all 6's on the board edges and 4's in the corners should be completely filled in, as they only involve 6 or 4 cells, respectively.

For this problem, you will be provided with various boards and solutions to each board. Write a function to determine if the solution is correct for the given board. The board will be filled with NaN's where there are no number clues; these cells should not be checked. The solution board will be filled with 1's (filled) and 0's (empty).

A related problem is Fill-a-pix - Solver (basic).