This Standard specifies two alternative image interchange formats for biometric authentication systems that utilize iris recognition. The first is based on a rectilinear image storage format that may be a raw, uncompressed array of intensity values or a compressed format such as that specified by the JPEG standard. Images may be monochrome or color with 256 or more intensity levels (grey or per-color), and vary in size depending on field of view and compression. Typical size is 25 & 8211;30 Kbytes for JPEG format. The second format is based on a polar image specification that requires certain pre-processing and image segmentation steps.