/** * JPEG and EXIF binary format constants for orientation parsing. */ /** Bytes of file prefix to scan, the APP1 EXIF segment sits near the start */ export const EXIF_SCAN_BYTE_LIMIT = 128 * 1024; /** JPEG start of image marker */ export const JPEG_SOI_MARKER = 0xffd8; /** APP1 segment marker byte, carries the EXIF payload */ export const APP1_MARKER = 0xe1; /** Start of scan marker byte, compressed data begins and no EXIF follows */ export const SOS_MARKER = 0xda; /** "Exif" signature opening the APP1 payload, big endian uint32 */ export const EXIF_SIGNATURE = 0x45786966; /** TIFF byte order mark for little endian ("II") */ export const TIFF_LITTLE_ENDIAN = 0x4949; /** TIFF magic number following the byte order mark */ export const TIFF_MAGIC = 42; /** EXIF tag id holding the orientation value */ export const EXIF_ORIENTATION_TAG = 0x0112; /** Size in bytes of one IFD directory entry */ export const IFD_ENTRY_SIZE = 12;