Vips.Image.conva (original) (raw)
Method
VipsImageconva
Declaration [src]
int
vips_conva (
VipsImage* in,
VipsImage** out,
VipsImage* mask,
...
)
Description [src]
Perform an approximate integer convolution of in with mask. This is a low-level operation, see vips_conv() for something more convenient.
The output image always has the same VipsBandFormat as the input image. Elements of mask are converted to integers before convolution.
Larger values for layers give more accurate results, but are slower. As layers approaches the mask radius, the accuracy will become close to exact convolution and the speed will drop to match. For many large masks, such as Gaussian, layers need be only 10% of this value and accuracy will still be good.
Smaller values of cluster will give more accurate results, but be slower and use more memory. 10% of the mask radius is a good rule of thumb.
Optional arguments
layers:gint, number of layers for approximationcluster:gint, cluster lines closer than this distance
This method is not directly available to language bindings.
Parameters
out
Type: VipsImage
Output image.
| The argument will be set by the function. |
|---|
| The caller of the method takes ownership of the returned data, and is responsible for freeing it. |
mask
Type: VipsImage
Convolution mask.
The data is owned by the caller of the method.
...
Type: ``
NULL-terminated list of optional named arguments.
Return value
Type: int
0 on success, -1 on error.