Expand description
A fast, iterative, correct approach to Stackblur, resulting in a very smooth and high-quality output, with no edge bleeding.
This crate implements a tweaked version of the Stackblur algorithm requiring
radius * 2 + 2
elements of space rather than radius * 2 + 1
, which is a
small tradeoff for much-increased visual quality.
The algorithm is exposed as an iterator (StackBlur
) that can wrap any
other iterator that yields elements of StackBlurrable
. The StackBlur
will then yield elements blurred by the specified radius.
Benefits of this crate
Stackblur is essentially constant-time. Regardless of the radius, it always performs only 1 scan over the input iterator and outputs exactly the same amount of elements.
Additionally, it produces results that are comparable to slow and expensive Gaussian blurs. As opposed to box blur which uses a basic rolling average, Stackblur uses a weighted average where each output pixel is affected more strongly by the inputs that were closest to it.
Despite that, Stackblur does not perform much worse compared to naive box blurs, and is quite cheap compared to full Gaussian blurs, at least for the CPU. The implementation in this crate will most likely beat most unoptimized blurs you can find on crates.io, as well as some optimized ones, and it is extremely flexible and generic.
For a full explanation of the improvements made to the Stackblur algorithm,
see the iter
module.
Comparison to the stackblur
crate
stackblur
suffers from edge bleeding and flexibility problems. For
example, it can only operate on buffers of 32-bit integers, and expects them
to be packed linear ARGB pixels. Additionally, it cannot operate on a 2D
subslice of a buffer (like imgref
allows for this crate), and it does not
offer any streaming iterators or documentation. And it also only supports
a blur radius of up to 255.
Usage
Aside from StackBlurrable
and StackBlur
which host their own
documentation, there are helper functions like blur
and blur_argb
that can be used to interact with 2D image buffers, due to the fact that
doing so manually involves unsafe code (if you want no-copy).
Re-exports
pub extern crate imgref;
Modules
- This module implements the
StackBlur
struct and the improved version of the Stackblur algorithm. - The home of
StackBlurrable
.
Functions
- Blurs a buffer, assuming one element per pixel.
- Blurs a buffer of 32-bit packed ARGB pixels (0xAARRGGBB).
- Blurs a buffer with SIMD, assuming one element per pixel.
- Blurs a buffer of 32-bit packed ARGB pixels (0xAARRGGBB) with SIMD.