BSQ

BSQ most commonly refers to the Band Sequential (BSQ) data interleave format used to store multi-spectral and hyperspectral raster imagery. In this layout, image data are stored band by band: all pixel values for the first spectral band are laid out contiguously, followed by the second band, and so on. This arrangement makes it straightforward to read or process a single spectral band without loading the other bands into memory.

BSQ files typically exist as raw binary data accompanied by a separate metadata header that describes dimensions, data type, number of bands, and the interleave format. The header may be provided in a plain text file (for example, a .hdr file) or embedded in project-specific metadata. The BSQ format is widely supported by geospatial software such as ENVI and ERDAS Imagine, as well as many open-source libraries, which read the band order and extract individual bands for analysis.

Compared with Band Interleaved by Line (BIL) and Band Interleaved by Pixel (BIP), BSQ stores all samples from one band contiguously, which can optimize access to single-band operations but may reduce cache efficiency when processing multiple bands together. It remains common in legacy datasets and some large hyperspectral projects, where per-band processing is common and external metadata remains acceptable; modern formats often add compression or streaming features.

Other uses of the acronym BSQ exist in different domains, but the Band Sequential format is the principal sense in geospatial imaging.