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Identify

hdrconv.identify

HDR format identification helpers.

This module provides functions for detecting HDR content and metadata in various image formats.

Public APIs
  • has_gain_map: Check if Apple HEIC file contains HDR gain map

has_gain_map(input_path)

Check if Apple HEIC file contains HDR gain map.

Scans the auxiliary images in a HEIC file to detect the presence of Apple's HDR gain map (URN: urn:com:apple:photo:2020:aux:hdrgainmap).

Parameters:

Name Type Description Default
input_path str

Path to the input HEIC image file.

 required

Returns:

Type Description
bool

True if an HDR gain map auxiliary image is found, False otherwise.
Note

This function does not validate the gain map data itself, only checks for its presence in the file metadata.

See Also
  • read_apple_heic: Extract gain map data from HEIC file.
Source code in src/hdrconv/identify/apple_heic.py 
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def has_gain_map(input_path: str) -> bool:
    """Check if Apple HEIC file contains HDR gain map.

        Scans the auxiliary images in a HEIC file to detect the presence of
        Apple's HDR gain map (URN: urn:com:apple:photo:2020:aux:hdrgainmap).

        Args:
            input_path: Path to the input HEIC image file.

        Returns:
            True if an HDR gain map auxiliary image is found, False otherwise.

        Note:
            This function does not validate the gain map data itself, only
            checks for its presence in the file metadata.

        See Also:
            - `read_apple_heic`: Extract gain map data from HEIC file.
    """
    has_gain_map = False
    heif_file = pillow_heif.read_heif(input_path, convert_hdr_to_8bit=False)

    if "aux" in heif_file.info:
        aux_info = heif_file.info["aux"]
        for urn, ids in aux_info.items():
            # print(f"  URN: {urn}, IDs: {ids}")
            if urn == HDR_GAIN_MAP_URN:
                has_gain_map = True
    return has_gain_map