1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
use super::RGB;
use super::{Error, Result};
use std::ops::{Index, IndexMut};
use std::path::Path;
/// Image as a flat buffer of pixels; accessible by (x, y) [Index]
#[derive(Clone, Debug, PartialEq)]
pub struct Img<P> {
buf: Vec<P>,
width: u32,
}
impl<P> Img<P> {
/// create an Img<P> from a buf and width. fails if `buf.len() % buf.width() != 0`
pub fn new(buf: impl IntoIterator<Item = P>, width: u32) -> Option<Self> {
let buf: Vec<P> = buf.into_iter().collect();
if width == 0 || buf.len() % width as usize != 0 {
None
} else {
Some(Img { buf, width })
}
}
/// create an Img<P> from a buf and length directly, skipping the bounds check.
/// ```
/// # use dither::prelude::*;
/// assert_eq!(
/// unsafe{Img::from_raw_buf(vec![2, 4, 6, 8], 2)},
/// Img::new(vec![2, 4, 6, 8], 2).unwrap()
/// );
/// ```
pub const unsafe fn from_raw_buf(buf: Vec<P>, width: u32) -> Self {
Img { buf, width }
}
/// pull the buffer out of the image as a vec.
/// ```
/// # use dither::prelude::*;
/// assert_eq!(Img::new(1..=4, 2).unwrap().into_vec(), vec![1, 2, 3, 4]);
/// ```
pub fn into_vec(self) -> Vec<P> {
self.buf
}
/// get the width of the image.
/// ```
/// # use dither::prelude::*;
/// assert_eq!(Img::new(0..12, 3).unwrap().width(), 3);
/// ```
pub fn width(&self) -> u32 {
self.width
}
/// returns an iterator over the pixels in the buffer
pub fn iter(&self) -> <&Self as IntoIterator>::IntoIter {
self.into_iter()
}
/// returns an iterator that allows modifying each pixel
pub fn iter_mut(&mut self) -> <&mut Self as IntoIterator>::IntoIter {
self.buf.iter_mut()
}
/// the height of the image; i.e, `buf.len() / width`
/// ```
/// # use dither::prelude::*;
/// assert_eq!(Img::new(0..12, 3).unwrap().height(), 4);
/// ```
pub fn height(&self) -> u32 {
self.len() as u32 / self.width
}
/// map a function on P across the image buffer, converting an `Img<P>` to an `Img<Q>`
///
/// ```
/// # use dither::prelude::*;
/// let img: Img<u8> = Img::new(1..=4, 2).unwrap();
/// let doubled: Img<u16> = Img::new(vec![2, 4, 6, 8], 2).unwrap();
/// assert_eq!(img.convert_with(|x| u16::from(x*2)), doubled);
/// ```
pub fn convert_with<Q>(self, convert: impl Fn(P) -> Q) -> Img<Q> {
let Img { buf, width } = self;
Img {
buf: buf.into_iter().map(convert).collect(),
width,
}
}
#[inline]
fn idx(&self, (x, y): (u32, u32)) -> usize {
((y * self.width) + x) as usize
}
/// the length of the image, in _pixels_. equal to [Img::width()]*[Img::height()]
pub fn len(&self) -> usize {
self.buf.len()
}
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Returns a reference to an element.
pub fn get(&self, (x, y): (u32, u32)) -> Option<&P> {
self.buf.get(self.idx((x, y)))
}
/// Returns a pair `(width, height)`.
pub fn size(&self) -> (u32, u32) {
(self.width, self.len() as u32 / self.width as u32)
}
}
impl<N: From<u8>> Img<RGB<N>> {
/// load an image as an RGB<N> after converting it. See [image::open] and [image::DynamicImage::to_rgb]
/// ```rust
/// use dither::prelude::*;
/// let img: Img<RGB<u8>> = Img::load("bunny.png").unwrap();
/// assert_eq!(img.size(), (620, 349));
/// ```
pub fn load(path: impl AsRef<Path>) -> Result<Self> {
match image::open(&path).and_then(|img| Ok(img.to_rgb())) {
Err(err) => Err(Error::input(err, path.as_ref())),
Ok(img) => Ok(Img {
buf: img.pixels().map(|p| RGB::from(p.data)).collect(),
width: img.width(),
}),
}
}
}
impl Img<RGB<u8>> {
/// save an image as a `.png` or `.jpg` to the path. the path extension determines the image type.
/// See [image::ImageBuffer::save]
pub fn save(self, path: &Path) -> Result<()> {
let (width, height) = self.size();
let buf = image::RgbImage::from_raw(width, height, self.raw_buf()).unwrap();
if let Err(err) = buf.save(path) {
Err(Error::output(err, path))
} else {
Ok(())
}
}
/// the raw_buf flattens out each RGB triplet;
/// ```
/// use dither::prelude::*;
/// let img: Img<RGB<u8>> = Img::new(vec![RGB(0, 1, 2), RGB(1, 1, 1)], 1).unwrap();
/// assert_eq!(img.raw_buf(), vec![0, 1, 2, 1, 1, 1]);
/// ```
pub fn raw_buf(self) -> Vec<u8> {
let mut raw_buf = Vec::with_capacity(self.len() * 3);
for RGB(r, g, b) in self.buf {
raw_buf.push(r);
raw_buf.push(g);
raw_buf.push(b);
}
raw_buf
}
}
impl<P> Index<(u32, u32)> for Img<P> {
type Output = P;
fn index(&self, (x, y): (u32, u32)) -> &P {
&self.buf[self.idx((x, y))]
}
}
impl<P> IndexMut<(u32, u32)> for Img<P> {
fn index_mut(&mut self, (x, y): (u32, u32)) -> &mut P {
let i = self.idx((x, y));
&mut self.buf[i]
}
}
impl<P> IntoIterator for Img<P> {
type Item = P;
type IntoIter = std::vec::IntoIter<P>;
fn into_iter(self) -> Self::IntoIter {
self.buf.into_iter()
}
}
impl<'a, P> IntoIterator for &'a Img<P> {
type Item = &'a P;
type IntoIter = std::slice::Iter<'a, P>;
fn into_iter(self) -> Self::IntoIter {
(&self.buf).iter()
}
}
impl<'a, P> IntoIterator for &'a mut Img<P> {
type Item = &'a mut P;
type IntoIter = std::slice::IterMut<'a, P>;
fn into_iter(self) -> Self::IntoIter {
(&mut self.buf).iter_mut()
}
}