Struct Pixmap 

pub struct Pixmap {
    pub width: u32,
    pub height: u32,
    pub data: Vec<u8>,
}

An RGBA pixel image, 4 bytes per pixel.

Row-major, top-to-bottom. Alpha is always 255 for DjVu pages.

Fields

width: u32

height: u32

data: Vec<u8>

RGBA pixel data, row-major. Length = width * height * 4.

Implementations

impl Pixmap

pub const MAX_PIXELS: usize

Maximum pixels per pixmap (64 megapixels, 256 MiB of RGBA).

Anything beyond this is a runaway DPI. Pixmap::try_new refuses it with PixmapError::TooLarge instead of attempting the allocation.

pub fn try_new( width: u32, height: u32, r: u8, g: u8, b: u8, a: u8, ) -> Result<Pixmap, PixmapError>

Create a new pixmap filled with the given RGBA color.

Errors

PixmapError::Overflow when width * height does not fit in usize; PixmapError::TooLarge when it exceeds Pixmap::MAX_PIXELS. Nothing is allocated in either case.

pub fn new(width: u32, height: u32, r: u8, g: u8, b: u8, a: u8) -> Pixmap

👎Deprecated since 0.34.0:

use Pixmap::try_new, which reports an oversized request instead of returning an empty pixmap

Create a new pixmap filled with the given RGBA color.

Returns an empty 0×0 pixmap if width * height would exceed Pixmap::MAX_PIXELS or overflow usize. That silent fallback is why this constructor is deprecated: use Pixmap::try_new and handle the PixmapError instead.

pub fn try_white(width: u32, height: u32) -> Result<Pixmap, PixmapError>

Create a white opaque pixmap.

Errors

The same as Pixmap::try_new.

pub fn white(width: u32, height: u32) -> Pixmap

Create a white opaque pixmap.

Returns an empty 0×0 pixmap when the size is refused; see Pixmap::try_white for the variant that reports why.

pub fn set_rgb(&mut self, x: u32, y: u32, r: u8, g: u8, b: u8)

Set pixel at (x, y) to an RGB value (alpha = 255). Silently ignores out-of-bounds writes (e.g. on an empty overflow pixmap).

pub fn get_pixel(&self, x: u32, y: u32) -> Option<&[u8]>

Get the 4 RGBA bytes at pixel (x, y), or None if out of bounds.

pub fn get_rgb(&self, x: u32, y: u32) -> (u8, u8, u8)

Get RGB at (x, y). Returns (0, 0, 0) for out-of-bounds reads.

pub fn to_rgb(&self) -> Vec<u8>

Extract RGB pixel data (3 bytes per pixel), discarding alpha.

pub fn to_ppm(&self) -> Vec<u8>

Encode as PPM (binary, P6 format). This is the format produced by ddjvu -format=ppm. Discards alpha channel.

pub fn rotate_cw90(&self) -> Pixmap

Rotate this pixmap 90° clockwise.

pub fn rotate_180(&self) -> Pixmap

Rotate this pixmap 180°.

pub fn rotate_ccw90(&self) -> Pixmap

Rotate this pixmap 90° counter-clockwise.

pub fn to_gray8(&self) -> GrayPixmap

Convert to 8-bit grayscale using ITU-R BT.601 luminance weights.

Y = 0.299·R + 0.587·G + 0.114·B

Returns a GrayPixmap with data.len() == width * height.

Trait Implementations

impl AsRef<[u8]> for Pixmap

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for Pixmap

fn clone(&self) -> Pixmap

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Pixmap

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for Pixmap

fn default() -> Pixmap

Returns the “default value” for a type.

impl Eq for Pixmap

impl PartialEq for Pixmap

fn eq(&self, other: &Pixmap) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Pixmap