Method

VipsImagewebpsave

Declaration [src] 

int
vips_webpsave (
  VipsImage* in,
  const char* filename,
  ...
)

Description [src]

Optional arguments:

  • Q: %gint, quality factor
  • lossless: %gboolean, enables lossless compression
  • preset: VipsForeignWebpPreset, choose lossy compression preset
  • smart_subsample: %gboolean, enables high quality chroma subsampling
  • smart_deblock: %gboolean, enables auto-adjusting of the deblocking filter
  • near_lossless: %gboolean, preprocess in lossless mode (controlled by Q)
  • alpha_q: %gint, set alpha quality in lossless mode
  • effort: %gint, level of CPU effort to reduce file size
  • target_size: %gint, desired target size in bytes
  • passes: %gint, number of entropy-analysis passes
  • min_size: %gboolean, minimise size
  • mixed: %gboolean, allow both lossy and lossless encoding
  • kmin: %gint, minimum number of frames between keyframes
  • kmax: %gint, maximum number of frames between keyframes

Write an image to a file in WebP format.

By default, images are saved in lossy format, with Q giving the WebP quality factor. It has the range 0 - 100, with the default 75.

Use preset to hint the image type to the lossy compressor. The default is

VIPS_FOREIGN_WEBP_PRESET_DEFAULT.

Set smart_subsample to enable high quality chroma subsampling.

Set smart_deblock to enable auto-adjusting of the deblocking filter. This can improve image quality, especially on low-contrast edges, but encoding can take significantly longer.

Use alpha_q to set the quality for the alpha channel in lossy mode. It has the range 1 - 100, with the default 100.

Use effort to control how much CPU time to spend attempting to reduce file size. A higher value means more effort and therefore CPU time should be spent. It has the range 0-6 and a default value of 4.

Use target_size to set the desired target size in bytes.

Use passes to set the number of entropy-analysis passes, by default 1, unless target_size is set, in which case the default is 3. It is not recommended to set passes unless you set target_size. Doing so will result in longer encoding times for no benefit.

Set lossless to use lossless compression, or combine near_lossless with Q 80, 60, 40 or 20 to apply increasing amounts of preprocessing which improves the near-lossless compression ratio by up to 50%.

For animated webp output, min_size will try to optimize for minimum size.

For animated webp output, kmax sets the maximum number of frames between keyframes. Setting 0 means only keyframes. kmin sets the minimum number of frames between frames. Setting 0 means no keyframes. By default, keyframes are disabled.

For animated webp output, mixed tries to improve the file size by mixing both lossy and lossless encoding.

Use the metadata items loop and delay to set the number of loops for the animation and the frame delays.

See also: vips_webpload(), vips_image_write_to_file().

This method is not directly available to language bindings.

Parameters

filename

Type: const char*

File to write to.

The data is owned by the caller of the method.
The value is a NUL terminated UTF-8 string.
...

Type: 

NULL-terminated list of optional named arguments.

Return value

Type: int

0 on success, -1 on error.