pyktx.ktx_basis_params module

class pyktx.ktx_basis_params.KtxBasisParams(codec: int = KtxBasisCodec.ETC1S, verbose: bool = False, no_sse: bool = False, thread_count: int = 1, etc1s_compression_level: int = 0, quality_level: int = 0, max_endpoints: int = 0, endpoint_rdo_threshold: int = 0, max_selectors: int = 0, selector_rdo_threshold: int = 0, input_swizzle: bytes = b'\x00\x00\x00\x00', normal_map: bool = False, pre_swizzle: bool = False, separate_rg_to_rgb_a: bool = False, no_endpoint_rdo: bool = False, no_selector_rdo: bool = False, uastc_flags: int = KtxPackUastcFlagBits.FASTEST, uastc_rdo: bool = False, uastc_rdo_quality_scalar: float = 0.0, uastc_rdo_dict_size: int = 0, uastc_rdo_max_smooth_block_error_scale: float = 10.0, uastc_rdo_max_smooth_block_std_dev: float = 18.0, uastc_rdo_dont_favor_simpler_modes: bool = False, uastc_rdo_no_multithreading: bool = False, uastc_hdr_quality: int = 1, uastc_hdr_uber_mode: bool = False, uastc_hdr_ultra_quant: bool = False, uastc_hdr_favor_astc: bool = False, rec_2020: bool = False, uastc_hdr_lambda: float = 0.0, uastc_hdr_level: int = 2)

Bases: object

Struct for passing extended params to KtxTexture2.compressBasis().

codec: int = 1

Basis Universal codec to use. Default is KtxBasisCodec.ETC1S/BasisLZ.

verbose: bool = False

If true, prints Basis Universal encoder operation details to stdout. Not recommended for GUI apps.

no_sse: bool = False

True to forbid use of the SSE instruction set. Ignored if CPU does not support SSE.

thread_count: int = 1

Number of threads used for compression. Default is 1.

etc1s_compression_level: int = 0

Encoding speed vs. quality tradeoff for etc1s. Range is [0,5].

Higher values are slower, but give higher quality. There is no default. Callers must explicitly set this value. Callers can use KTX_ETC1S_DEFAULT_COMPRESSION_LEVEL as a default value. Currently this is 2.

Type:

ETC1S/BasisLZ

quality_level: int = 0

Compression quality. Range is [1,255].

Lower gives better compression/lower quality/faster. Higher gives less compression/higher quality/slower. This automatically determines values for max_endpoints, max_selectors, endpoint_rdo_threshold, and selector_rdo_threshold for the target quality level. Setting these parameters overrides the values determined by quality_level which defaults to 128 if neither it nor both of max_endpoints and max_selectors have been set.

Both of max_endpoints and max_selectors must be set for them to have any effect. quality_level will only determine values for endpoint_rdo_threshold and selector_rdo_threshold when its value exceeds 128, otherwise their defaults will be used.

Type:

ETC1S/BasisLZ and UASTC LDR 4x4

max_endpoints: int = 0

Manually set the max number of color endpoint clusters.

Range is [1,16128]. Default is 0, unset. If this is set, max_selectors must also be set, otherwise the value will be ignored.

Type:

ETC1S/BasisLZ

endpoint_rdo_threshold: int = 0

Set endpoint RDO quality threshold. The default is 1.25.

Lower is higher quality but less quality per output bit (try [1.0,3.0]. This will override the value chosen by quality_level.

Type:

ETC1S/BasisLZ

max_selectors: int = 0

Manually set the max number of color selector clusters. Range is [1,16128].

Default is 0, unset. If this is set, max_endpoints must also be set, otherwise the value will be ignored.

Type:

ETC1S/BasisLZ

selector_rdo_threshold: int = 0

Set selector RDO quality threshold. The default is 1.5.

Lower is higher quality but less quality per output bit (try [1.0,3.0]). This will override the value chosen by @c qualityLevel.

Type:

ETC1S/BasisLZ

input_swizzle: bytes = b'\x00\x00\x00\x00'

A swizzle to apply before encoding.

It must match the regular expression /^[rgba01]{4}$/. If both this and pre_swizzle are specified KtxTexture2.compressBasis() will raise INVALID_OPERATION.

normal_map: bool = False

Tunes codec parameters for better quality on normal maps (no selector RDO, no endpoint RDO) and sets the texture’s DFD appropriately.

Only valid for linear textures.

pre_swizzle: bool = False

If the texture has swizzle metadata, apply it before compressing.

Swizzling, like rabb may yield drastically different error metrics if done after supercompression.

separate_rg_to_rgb_a: bool = False

This was and is a no-op.

2-component inputs have always been automatically separated using an “rrrg” input_swizzle.

no_endpoint_rdo: bool = False

Disable endpoint rate distortion optimizations.

Slightly faster, less noisy output, but lower quality per output bit.

Type:

ETC1S/BasisLZ

no_selector_rdo: bool = False

Disable selector rate distortion optimizations.

Slightly faster, less noisy output, but lower quality per output bit.

Type:

ETC1S/BasisLZ

uastc_flags: int = 0

A set of KtxPackUastcFlagBits controlling UASTC encoding.

The most important value is the level given in the least-significant 4 bits which selects a speed vs quality tradeoff.

Type:

UASTC LDR 4x4

uastc_rdo: bool = False

Enable Rate Distortion Optimization (RDO) post-processing.

Type:

UASTC LDR 4x4

uastc_rdo_quality_scalar: float = 0.0

RDO quality scalar (lambda).

Lower values yield higher quality/larger LZ compressed files, higher values yield lower quality/smaller LZ compressed files. A good range to try is [.2,4]. Full range is [.001,50.0]. Default is 1.0.

Type:

UASTC LDR 4x4

uastc_rdo_dict_size: int = 0

RDO dictionary size in bytes. Default is 4096. Lower values=faster, but give less compression. Range is [64,65536].

Type:

UASTC LDR 4x4

uastc_rdo_max_smooth_block_error_scale: float = 10.0

RDO max smooth block error scale. Range is [1,300]. Default is 10.0, 1.0 is disabled. Larger values suppress more artifacts (and allocate more bits) on smooth blocks.

Type:

UASTC LDR 4x4

uastc_rdo_max_smooth_block_std_dev: float = 18.0

RDO max smooth block standard deviation. Range is [.01,65536.0]. Default is 18.0. Larger values expand the range of blocks considered smooth.

Type:

UASTC LDR 4x4

uastc_rdo_dont_favor_simpler_modes: bool = False

Do not favor simpler UASTC modes in RDO mode.

Type:

UASTC LDR 4x4

uastc_rdo_no_multithreading: bool = False

Disable RDO multithreading (slightly higher compression, deterministic).

Type:

UASTC LDR 4x4

uastc_hdr_quality: int = 1

Valid range is [0,4] - higher=slower but higher quality. Default=1. Level 0=fastest/lowest quality, 3=highest practical setting, 4=exhaustive

uastc_hdr_uber_mode: bool = False

Allow the UASTC HDR 4x4 encoder to try varying the CEM 11 selectors more for slightly higher quality (slower). This may negatively impact BC6H quality, however.

Type:

UASTC HDR 4x4

uastc_hdr_ultra_quant: bool = False

Try to find better quantized CEM 7/11 endpoint values (slower).

Type:

UASTC HDR 4x4

uastc_hdr_favor_astc: bool = False

By default the UASTC HDR 4x4 encoder tries to strike a balance or even slightly favor BC6H quality. If this option is specified, ASTC HDR 4x4 quality is favored instead.

Type:

UASTC HDR 4x4

rec_2020: bool = False

The input image’s gamut is Rec. 2020 vs. the default Rec. 709 - for accurate colorspace error calculations.

Type:

UASTC HDR 6x6i specific option

uastc_hdr_lambda: float = 0.0

Enables rate distortion optimization (RDO). The higher this value, the lower the quality, but the smaller the file size. Try 100-20000, or higher values on some images.

Type:

UASTC HDR 6x6i specific option

uastc_hdr_level: int = 2

Controls the 6x6 HDR intermediate mode encoder performance vs. max quality tradeoff. X may range from [0,12]. Default level is 2.

Type:

UASTC HDR 6x6i specific option