are often able to detect and store wavelengths beyond the visible spectrum; the large CCD bitmapped sensor at the Vera C. Rubin Observatory captures 3.2 gigapixels in a single image (6.4 GB raw), over six color channels which exceed the spectral range of human color vision. Applications Image storage Most computer images are stored in raster graphics formats or compressed variations, including GIF, JPEG, and PNG, which are popular on the World Wide Web. A raster data structure is based on a (usually rectangular, square-based) tessellation of the 2D plane into cells, each containing a single value. To store the data in a file, the two-dimensional array must be serialized. The most common way to do this is a row-major format, in which the cells along the first (usually top) row are listed left to right, followed immediately by those of the second row, and so on. In the example at right, the cells of tessellation A are overlaid on the point pattern B resulting in an array C of quadrant counts representing the number of points in each cell. For purposes of visualization a lookup table has been used to color each of the cells in an image D. Here are the numbers as a serial row-major array: 1 3 0 0 1 12 8 0 1 4 3 3 0 2 0 2 1 7 4 1 5 4 2 2 0 3 1 2 2 2 2 3 0 5 1 9 3 3 3 4 5 0 8 0 2 4 3 2 8 4 3 2 2 7 2 3 2 10 1 5 2 1 3 7 To reconstruct the two-dimensional grid, the file must include a header section at the beginning that contains at least the number of columns, and the pixel datatype (especially the number of bits or bytes per value) so the reader knows where each value ends to start reading the next one. Headers may also include the number of rows, georeferencing parameters for geographic data, or other metadata tags, such as those specified in the Exif standard. Compression High-resolution raster grids contain a large number of pixels, and thus consume a large amount of memory. This has led to multiple approaches to compressing the data volume into smaller files. The most common strategy is to look for patterns or trends in the pixel values, then store a parameterized form