Transcoding
==============================

Located in the output tab.

Transcoding Options
------------------------------

JPEG XL
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

**Quality**
    Higher values result in higher quality and higher file size.

    * 90 - visually lossless
    * 80 - high quality and reasonable file size
    * 70 - medium-high quality and small file size
    * 60 - space-saving, noticeable blurriness

**Effort**
    higher is better quality or lower file size but slower. Its behavior depends on the mode used.
    
    * 7 - normal speed with modest file size and good quality.
    * 9 - very slow but produces lowest file size or best quality.

    Behavior
        * Lossy - higher values result in higher quality. File size may end up larger, especially for non-photographic images.
        * Lossless and Lossy Modular - higher values always result in lower file size.

**Lossy Modular**
    * Disabled - uses VarDCT mode, preferred for photographic images.
    * Enabled - offers lower file size and increased eligibility for non-photos. It has a drawback of introducing discoloration and artifacts on the edges. Use it sparingly.

AVIF
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

**Quality**
    Higher is better quality and bigger size.
    
    * 90 - visually lossless
    * 80 - high quality and file size
    * 70 - good balance between quality and file size
    * 60 - space-saving

**Speed**
    lower is slower, better quality, and smaller file size
    
    * 6 - regular speed, and good quality
    * 0 - very slow, the best quality, and smallest file size

WebP
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

**Quality**
    Higher is better quality and bigger size.

    * 90 - high quality and large file size
    * 80 - reasonable quality and file size
    * 60 - looks fine only from far away

**Method**
    Higher means better quality and/or smaller file size.

    Typical values: 4 - 6

    **Behavior**
        * Lossless: higher values result in lower file size.
        * Lossy: higher value result in lower file size and typically higher quality (can be subjective).

JPEG
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

**Quality**
    Higher is better quality and bigger size.

    * 95 - high quality and very large file size
    * 90 - reasonably high quality and large file size
    * 80 - reasonable quality and file size
    * 60 - looks fine only from far away


**Chroma Subsampling**
    Controls color compression. Lower number means less color information and smaller file size.

    * Default - usually picks 4:4:4, but tries to match the input
    * 4:4:4 - full color, the highest quality and file size
    * 4:2:2 - less color (small visual difference), and significant space-saving
    * 4:2:0 - colors may appear washed out
    * 4:0:0 - grayscale

    `Learn more <https://en.wikipedia.org/wiki/Chroma_subsampling#Regarding_gamma_and_transfer_functions>`_

Smallest Lossless
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Converts to multiple formats and outputs the smallest one.

.. caution::

    Be mindful of the maximum supported bit depth. See :doc:`this page <supported_formats>`.

Related
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* :doc:`format_comparison`
* :doc:`lossless_jpeg_transcoding`