There are two sets of tools: a new set with a unified front end, ktx, and an older set of individual tools. Both are documented here.

ktx Overview

ktx includes the following tools:

Tool	Description	Equivalent old tool
ktx create	Create a KTX2 file from various input files	`toktx`
ktx extract	Export selected images from a KTX2 file	-
ktx encode	Encode a KTX2 file	`ktxsc`
ktx transcode	Transcode a KTX2 file	-
ktx info	Prints information about a KTX2 file	`ktxinfo`
ktx validate	Validate a KTX2 file	`ktx2check`
ktx help	Display help information about the ktx tools	-

Equivalent old tools are deprecated and will be removed soon.

Some features of old tools are not currently available in the new equivalent.

Old Tool	New Tool	Missing Features
toktx	create	JPEG and NBPM input and scaling/resizing of input images.
ktxsc	encode	ASTC encoding. This can be done in `create`. Deflation of a KTX2 file with zlib or zstd.

The command-line syntax and semantics differ from the old tools including, but not limited to:

KTX 1.0 files are not supported by the new tools.
Words in multi-word option names are connected with - instead of _.
Individual option names may differ between the old and new tools.
The ktx validate tool may be stricter than ktx2check or otherwise differ in behavior, as the new tool enforces all rules of the KTX 2.0 specification. In addition, all new tools that accept KTX 2.0 files as input will be validated in a similar fashion as they would be with the ktx validate tool and will fail on the first specification rule violation, if there is one. It also has the option to output the validation results in human readable text format or in JSON format (both formatted and minified options are available), as controlled by the --format command-line option.
The ktx validate tool also supports validating KTX 2.0 files against the additional restrictions defined by the KHR_texture_basisu extension. Use the --gltf-basisu command-line option to verify glTF and WebGL compatibility.
The new ktx info tool produces a unified and complete output of all metadata in KTX 2.0 files and can provide output in human readable text format or in JSON format (both formatted and minified options are available), as controlled by the --format command-line option.
The source repository also includes the JSON schemas that the JSON outputs of the ktx info and ktx validate tools comply to.
The ktx create tool takes an explicit Vulkan format argument (--format) instead of inferring the format based on the provided input files as toktx, and thus doesn't perform any implicit color-space conversions except gamma 2.2 to sRGB. Use the --assign-oetf, --convert-oetf, --assign-primaries, and the new --convert-primaries for fine grained control over color-space interpretation and conversion.
The ktx create tool does not support resizing or scaling like toktx, and, in general, does not perform any image transformations except the optional color-space conversion and mipmap generation options. Users should resize input images to the appropriate resolution before converting them to KTX 2.0 files.
The ktx create and ktx extract tools consume and produce, respectively, image file formats that best suit the used Vulkan format. In general, barring special cases, 8-bit and 16-bit normalized integer formats are imported from and exported to PNG files, while integer and floating point formats are imported from and exported to EXR files based on predefined rules. This may be extended in the future using additional command line options and in response to support for other image file formats.
The new tools and updated libktx support ZLIB supercompression besides the BasisLZ and Zstd supercompression schemes supported previously.

Please refer to the manual pages or use the --help command-line option for further details on the options available and associated semantics for each individual command.

This page last modified $Date: Fri Dec 22 22:46:49 2023 +0900 $