Struct ProfileHeader 

pub struct ProfileHeader {
    pub size: u32,
    pub preferred_cmm: u32,
    pub version: ProfileVersion,
    pub device_class: DeviceClass,
    pub data_color_space: ColorSpace,
    pub pcs: ColorSpace,
    pub rendering_intent: RenderingIntent,
    pub creator: u32,
    pub profile_id: [u8; 16],
}

The fixed 128-byte header that opens every ICC profile (ICC.1:2022 §7.2).

The header records the profile’s size, the device/connection color spaces it relates, the profile version, the default rendering intent, and an MD5 identifier. Only the most load-bearing fields are modelled here; the reserved and date/platform fields are added in the implementation phase.

Fields

size: u32

Total profile size in bytes (size field).

preferred_cmm: u32

Preferred CMM signature (e.g. 'appl', 'lcms'), or zero.

version: ProfileVersion

Profile format version (the major.minor.bugfix of the spec it conforms to).

device_class: DeviceClass

What kind of device or transform the profile describes.

data_color_space: ColorSpace

The device color space the profile’s data side uses (the A side).

pcs: ColorSpace

The profile connection space (the B side) — always XYZ or Lab.

rendering_intent: RenderingIntent

The default rendering intent.

creator: u32

Profile creator signature, or zero.

profile_id: [u8; 16]

The 16-byte profile ID (an MD5 of the profile with certain fields zeroed), or all-zero if unset.