.. _flash_documentation-movie_file_format: Movie File Format ================= Image stacks (movies) are saved as monochrome, uncompressed .tif files with the 16-bit pixel data. For each frame, the image data is flipped vertically and/or horizontally according to the configuration and the images from all active cameras are then assembled into a montage. The montage is designed to simulate the layout of an optical splitter. For 4-channel acquisitions, the panel order by wavelength is bottom-left, top-left, top-right, bottom-right (Cy2, Cy3, Cy5, Cy7, respectively). For 3-channel acquisitions, the field corresponding to the inactive camera is filled with zeros. For 2-channel acquisitions, the fields are tiled horizontally left-to-right by wavelength. Movie files use the BigTIFF standard, which uses 64-bit offsets to enable file sizes larger than 4 GB: `https://www.awaresystems.be/imaging/tiff/bigtiff.html `_ . This is required for instruments with sCMOS cameras, which often produce movies that are 30 GB or larger. The movies have one Image File Directory (IFDs) for each frame, all of which are stored at the beginning of the file. The pixel data is saved in one contiguous block at the end of the file (offset=16384 bytes), with each frame being a single stripe without any intervening bytes. This allows the pixel data to be efficiently read from disk for data analysis. The movies include many metadata tags, but these two are of particular importance. The pixel size parameter is set for the Flash cameras and a 60x objective and may not be correct for any other setup. - ExposureTime (33434): interval between camera frames. - ImageDescription (270): plain-text description of the experiment and instrument parameters, which can be used to automate the analysis process.