Will HDR automatically survive in HEIC?+
The source can carry HDR information and HEIC has HDR-capable variants. Working radiometric values and display-referred HDR are different representations. Range, primaries, transfer function and signalling must be mapped explicitly; the future engine may instead produce SDR. HDR preservation is not promised by format support.
Will the background become transparent?+
The target can store an alpha channel, but converting an opaque image does not create transparent areas. Removing a background is a separate editing step.
Which compression mode will HEIC use?+
HEIC commonly uses lossy HEVC; HEVC also has lossless coding tools. Actual quality, bit depth and chroma depend on the encoded profile and settings, not on the .heic extension. HEIC permits different encoding modes or container representations. Its format name alone does not promise lossless output, a quality setting or a size reduction. The future engine must choose a supported codec and sample representation; inspect the target’s compression notes below.
Are bit depth and colour values guaranteed to match?+
Source and target sample models can differ in precision, channel layout, colour space and transfer function. Lossless compression only preserves the samples actually encoded; a precision reduction or colour conversion can already change them. The future engine defines numeric mapping, orientation and colour conversion; canonical depth facts are listed below where available.
Will metadata and colour profiles be retained?+
HDR: Radiance header, EXPOSURE, FORMAT → HEIC: Exif, XMP, ICC, NCLX. Which fields are copied, rewritten or omitted will depend on the future engine; retention is not implemented yet.