Coordinates and Raster

Plot Point to Pixel

Map an exact continuous point to the pixel cell that contains it by taking the floor of each coordinate.

Example

Use floor to map a continuous point to the pixel cell that contains it.

highlighted = computed this step

Step 1 — Start with a pixel grid

Start with a continuous point over the grid.

use floor to choose the cell\text{use floor to choose the cell}
Continuous point to pixelThe point floors to row 2, column 2.01234501234P

Step 2 — Floor the x-coordinate

Floor x to choose the pixel column.

⌊73⌋=2\lfloor \frac{7}{3} \rfloor= \hl{2}

Step 3 — Floor the y-coordinate

Floor y to choose the pixel row.

⌊114⌋=2\lfloor \frac{11}{4} \rfloor= \hl{2}

Step 4 — Highlight the pixel

Highlight the cell containing the point.

pixel=(2,2)pixel=( \hl{2} , \hl{2} )
Continuous point to pixelThe point floors to row 2, column 2.01234501234P
plot-point-to-pixel A pixel cell is addressed by an integer row and column. The floor function chooses the cell containing a non-integer coordinate.