5.30. Export Image as JPEG 2000 codestream

5.30.1. نمای کلّی

The JPEG 2000 format was developed to succeed JPEG. It supports both lossy and lossless compression, and high dynamic range images. GIMP also has an exporter for storing a JPEG 2000 image inside a HEIF container.

شكل 15.78. The JPEG 2000 codestream Export dialog

The JPEG 2000 codestream Export dialog

5.30.2. گزینه ها

ICT compression

When checked, ICT (Irreversible Color Transform) compression will be used instead of RCT (Reversible Color Transform). ICT can cause rounding errors, which means it is lossy, contrary to RCT.

Export as CMYK

If you have a CMYK profile assigned to your image as soft-proofing profile, this setting can be checked to have your image exported using that CMYK profile. This is sometimes required when you have your image professionally printed. Your printing company will tell you if this is needed.

If this setting is disabled, you don't have a soft-proofing profile set for this image yet. See assigning a Soft-Proof Profile.

The name of the CMYK profile that is assigned to this image will be shown below this setting.

Number of resolutions

Set this to the number of resolutions you want to be stored in your image. This adds reduced size images for faster loading.

Progression order

This defines how image data is organized in the JPEG 2000 codestream, allowing you to prioritize progressive viewing by quality, resolution or component. The letters stand for Layer, Resolution, Component, Position.

LRCP

The default. Shows quality layers first, then resolution, then components, then spatial positions (good for gradual quality increase).

RLCP

Shows all data for the lowest resolution, then adds layers, then moves to the next resolution level.

PCRL

Shows full resolution tiles first, then fills in layers, good for fast preview.

RPCL

Focuses on spatial detail within a tile first.

CPRL

Focuses on full data for one component before moving to the next.

Compliance profile

Select the compliance profile you require for your image.

Standard Profile

The default conforms to the basic standard functionality for JPEG 2000 images.

Cinema2K (24 FPS)

Generates a codestream compliant with the Digital Cinema Specifications for 2K resolution content at 24 FPS.

Cinema2K (48 FPS)

Generates a codestream compliant with the Digital Cinema Specifications for 2K resolution content at 48 FPS.

Cinema4K (24 FPS)

Generates a codestream compliant with the Digital Cinema Specifications for 4K resolution content at 24 FPS.