Dr. Nonogram

Nonograms, also known as Hanjie, Paint by Numbers, Picross, Griddlers, and Pic-a-Pix, among other names, are intricate picture logic puzzles that challenge players to reveal hidden images by carefully filling cells in a grid based on numerical hints provided alongside the grid.

In this particular puzzle genre, the numbers act as a form of discrete tomography, indicating how many consecutive filled squares exist in each row or column. For instance, a hint such as "4 8 3" suggests sequences of four, eight, and three filled squares, respectively, with vacant cells interspersed between these sets.

While these puzzles typically present themselves in black and white—a representation of binary images—they can also feature colorful variations. When color is added to the mix, the numeric clues are correspondingly colored to denote the shades of the squares. It's worth noting that unlike their monochromatic counterparts, two differently colored numbers may or may not be separated by an empty space. For example, a sequence consisting of a black four followed by a red two could indicate four black cells with intermediate empty spaces preceding two red squares or simply denote an immediate transition from four black squares to two red ones.

Nonograms come without inherent size limitations and offer layouts beyond conventional square grids. The name "Nonograms" pays tribute to Non Ishida, one of the original creators of this engaging puzzle style.