Module sample

Functions and filters for the sampling of pixels.

Structs

Filter 🔒

A Representation of a separable filter.

FloatNearest 🔒

ThumbnailSum 🔒

Local struct for keeping track of pixel sums for fast thumbnail averaging

Enums

FilterType

Available Sampling Filters.

Functions

bc_cubic_spline 🔒

blur

Performs a Gaussian blur on the supplied image. sigma is a measure of how much to blur by. Use crate::imageops::fast_blur() for a faster but less accurate version. This method assumes alpha pre-multiplication for images that contain non-constant alpha.

box_kernel 🔒

Calculate the box kernel. Only pixels inside the box should be considered, and those contribute equally. So this method simply returns 1.

catmullrom_kernel 🔒

Calculate the Catmull-Rom cubic spline. Also known as a form of BiCubic sampling in two dimensions.

filter3x3

Perform a 3x3 box filter on the supplied image. kernel is an array of the filter weights of length 9.

gaussian 🔒

The Gaussian Function. r is the standard deviation.

gaussian_kernel 🔒

Calculate the gaussian function with a standard deviation of 0.5

horizontal_sample 🔒

interpolate_bilinear

Linearly sample from an image using coordinates in [0, w-1] and [0, h-1].

interpolate_nearest

Sample from an image using coordinates in [0, w-1] and [0, h-1], taking the nearest pixel.

lanczos 🔒

lanczos3_kernel 🔒

Calculate the lanczos kernel with a window of 3

resize

Resize the supplied image to the specified dimensions. nwidth and nheight are the new dimensions. filter is the sampling filter to use. This method assumes alpha pre-multiplication for images that contain non-constant alpha.

sample_bilinear

Linearly sample from an image using coordinates in [0, 1].

sample_nearest

Sample from an image using coordinates in [0, 1], taking the nearest coordinate.

sinc 🔒

thumbnail

Resize the supplied image to the specific dimensions.

thumbnail_sample_block 🔒

Get a pixel for a thumbnail where the input window encloses at least a full pixel.

thumbnail_sample_fraction_both 🔒

Get a single pixel for a thumbnail where the input window does not enclose any full pixel.

thumbnail_sample_fraction_horizontal 🔒

Get a thumbnail pixel where the input window encloses at least a vertical pixel.

thumbnail_sample_fraction_vertical 🔒

Get a thumbnail pixel where the input window encloses at least a horizontal pixel.

triangle_kernel 🔒

Calculate the triangle function. Also known as BiLinear sampling in two dimensions.

unsharpen

Performs an unsharpen mask on the supplied image. sigma is the amount to blur the image by. threshold is the threshold for minimal brightness change that will be sharpened.

vertical_sample 🔒