Struct rute::auto::image::Image

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pub struct Image<'a> { /* private fields */ }

Expand description

Notice these docs are heavy WIP and not very relevent yet

Qt provides four classes for handling image data: QImage, QPixmap, QBitmap and QPicture. QImage is designed and optimized for I/O, and for direct pixel access and manipulation, while QPixmap is designed and optimized for showing images on screen. QBitmap is only a convenience class that inherits QPixmap, ensuring a depth of 1. Finally, the QPicture class is a paint device that records and replays QPainter commands.

Because QImage is a QPaintDevice subclass, QPainter can be used to draw directly onto images. When using QPainter on a QImage, the painting can be performed in another thread than the current GUI thread.

The QImage class supports several image formats described by the Format enum. These include monochrome, 8-bit, 32-bit and alpha-blended images which are available in all versions of Qt 4.x.

QImage provides a collection of functions that can be used to obtain a variety of information about the image. There are also several functions that enables transformation of the image.

QImage objects can be passed around by value since the QImage class uses implicit data sharing . QImage objects can also be streamed and compared.

Note: If you would like to load QImage objects in a static build of Qt, refer to the Plugin HowTo

Warning: Painting on a QImage with the format QImage::Format_Indexed8 is not supported.

Reading and Writing Image Files

QImage provides several ways of loading an image file: The file can be loaded when constructing the QImage object, or by using the load() or loadFromData() functions later on. QImage also provides the static fromData() function, constructing a QImage from the given data. When loading an image, the file name can either refer to an actual file on disk or to one of the application’s embedded resources. See The Qt Resource System overview for details on how to embed images and other resource files in the application’s executable.

Simply call the save() function to save a QImage object.

The complete list of supported file formats are available through the QImageReader::supportedImageFormats() and QImageWriter::supportedImageFormats() functions. New file formats can be added as plugins. By default, Qt supports the following formats:

Format
Description
Qt’s support
BMP
Windows Bitmap
Read/write
GIF
Graphic Interchange Format (optional)
Read
JPG
Joint Photographic Experts Group
Read/write
JPEG
Joint Photographic Experts Group
Read/write
PNG
Portable Network Graphics
Read/write
PBM
Portable Bitmap
Read
PGM
Portable Graymap
Read
PPM
Portable Pixmap
Read/write
XBM
X11 Bitmap
Read/write
XPM
X11 Pixmap
Read/write

Image Information

QImage provides a collection of functions that can be used to obtain a variety of information about the image:

Available Functions
Geometry
The size(), width(), height(), dotsPerMeterX(), and dotsPerMeterY() functions provide information about the image size and aspect ratio. The rect() function returns the image’s enclosing rectangle. The valid() function tells if a given pair of coordinates is within this rectangle. The offset() function returns the number of pixels by which the image is intended to be offset by when positioned relative to other images, which also can be manipulated using the setOffset() function.
Colors
The color of a pixel can be retrieved by passing its coordinates to the pixel() function. The pixel() function returns the color as a QRgb value indepedent of the image’s format. In case of monochrome and 8-bit images, the colorCount() and colorTable() functions provide information about the color components used to store the image data: The colorTable() function returns the image’s entire color table. To obtain a single entry, use the pixelIndex() function to retrieve the pixel index for a given pair of coordinates, then use the color() function to retrieve the color. Note that if you create an 8-bit image manually, you have to set a valid color table on the image as well. The hasAlphaChannel() function tells if the image’s format respects the alpha channel, or not. The allGray() and isGrayscale() functions tell whether an image’s colors are all shades of gray. See also the Pixel Manipulation and Image Transformations sections.
Text
The text() function returns the image text associated with the given text key. An image’s text keys can be retrieved using the textKeys() function. Use the setText() function to alter an image’s text.
Low-level information
The depth() function returns the depth of the image. The supported depths are 1 (monochrome), 8, 16, 24 and 32 bits. The bitPlaneCount() function tells how many of those bits that are used. For more information see the Image Formats section. The format(), bytesPerLine(), and sizeInBytes() functions provide low-level information about the data stored in the image. The cacheKey() function returns a number that uniquely identifies the contents of this QImage object.

Pixel Manipulation

The functions used to manipulate an image’s pixels depend on the image format. The reason is that monochrome and 8-bit images are index-based and use a color lookup table, while 32-bit images store ARGB values directly. For more information on image formats, see the Image Formats section.

In case of a 32-bit image, the setPixel() function can be used to alter the color of the pixel at the given coordinates to any other color specified as an ARGB quadruplet. To make a suitable QRgb value, use the qRgb() (adding a default alpha component to the given RGB values, i.e. creating an opaque color) or qRgba() function. For example:

{2,1}32-bit

In case of a 8-bit and monchrome images, the pixel value is only an index from the image’s color table. So the setPixel() function can only be used to alter the color of the pixel at the given coordinates to a predefined color from the image’s color table, i.e. it can only change the pixel’s index value. To alter or add a color to an image’s color table, use the setColor() function.

An entry in the color table is an ARGB quadruplet encoded as an QRgb value. Use the qRgb() and qRgba() functions to make a suitable QRgb value for use with the setColor() function. For example:

{2,1} 8-bit

For images with more than 8-bit per color-channel. The methods setPixelColor() and pixelColor() can be used to set and get with QColor values.

QImage also provide the scanLine() function which returns a pointer to the pixel data at the scanline with the given index, and the bits() function which returns a pointer to the first pixel data (this is equivalent to scanLine(0)).

Image Formats

Each pixel stored in a QImage is represented by an integer. The size of the integer varies depending on the format. QImage supports several image formats described by the Format

enum.

Monochrome images are stored using 1-bit indexes into a color table with at most two colors. There are two different types of monochrome images: big endian (MSB first) or little endian (LSB first) bit order.

8-bit images are stored using 8-bit indexes into a color table, i.e. they have a single byte per pixel. The color table is a QVector, and the QRgb typedef is equivalent to an unsigned int containing an ARGB quadruplet on the format 0xAARRGGBB.

32-bit images have no color table; instead, each pixel contains an QRgb value. There are three different types of 32-bit images storing RGB (i.e. 0xffRRGGBB), ARGB and premultiplied ARGB values respectively. In the premultiplied format the red, green, and blue channels are multiplied by the alpha component divided by 255.

An image’s format can be retrieved using the format() function. Use the convertToFormat() functions to convert an image into another format. The allGray() and isGrayscale() functions tell whether a color image can safely be converted to a grayscale image.

Image Transformations

QImage supports a number of functions for creating a new image that is a transformed version of the original: The createAlphaMask() function builds and returns a 1-bpp mask from the alpha buffer in this image, and the createHeuristicMask() function creates and returns a 1-bpp heuristic mask for this image. The latter function works by selecting a color from one of the corners, then chipping away pixels of that color starting at all the edges.

The mirrored() function returns a mirror of the image in the desired direction, the scaled() returns a copy of the image scaled to a rectangle of the desired measures, and the rgbSwapped() function constructs a BGR image from a RGB image.

The scaledToWidth() and scaledToHeight() functions return scaled copies of the image.

The transformed() function returns a copy of the image that is transformed with the given transformation matrix and transformation mode: Internally, the transformation matrix is adjusted to compensate for unwanted translation, i.e. transformed() returns the smallest image containing all transformed points of the original image. The static trueMatrix() function returns the actual matrix used for transforming the image.

There are also functions for changing attributes of an image in-place:

Function
Description
setDotsPerMeterX()
Defines the aspect ratio by setting the number of pixels that fit horizontally in a physical meter.
setDotsPerMeterY()
Defines the aspect ratio by setting the number of pixels that fit vertically in a physical meter.
fill()
Fills the entire image with the given pixel value.
invertPixels()
Inverts all pixel values in the image using the given InvertMode value.
setColorTable()
Sets the color table used to translate color indexes. Only monochrome and 8-bit formats.
setColorCount()
Resizes the color table. Only monochrome and 8-bit formats.

See also: [ImageReader] [ImageWriter] Pixmap [SvgRenderer] {Image Composition Example} {Image Viewer Example} {Scribble Example} {Pixelator Example}

Licence

The documentation is an adoption of the original Qt Documentation and provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation.

Struct rute::auto::image::Image

Implementations

impl<'a> Image<'a>

pub fn new() -> Image<'a>

pub fn swap<I: ImageTrait<'a>>(&self, other: &I) -> &Self

pub fn is_null(&self) -> bool

pub fn dev_type(&self) -> i32

pub fn detach(&self) -> &Self

pub fn is_detached(&self) -> bool

pub fn copy<R: RectTrait<'a>>(&self, rect: &R) -> Image<'_>

pub fn copy_2(&self, x: i32, y: i32, w: i32, h: i32) -> Image<'_>

pub fn format(&self) -> Format

pub fn convert_to_format( &self, f: Format, flags: ImageConversionFlags) -> Image<'_>

pub fn convert_to_format_2( &self, f: Format, flags: ImageConversionFlags) -> Image<'_>

pub fn reinterpret_as_format(&self, f: Format) -> bool

pub fn width(&self) -> i32

pub fn height(&self) -> i32

pub fn size(&self) -> Size<'_>

pub fn rect(&self) -> Rect<'_>

pub fn depth(&self) -> i32

pub fn color_count(&self) -> i32

pub fn bit_plane_count(&self) -> i32

pub fn set_color_count(&self, arg0: i32) -> &Self

pub fn all_gray(&self) -> bool

pub fn is_grayscale(&self) -> bool

pub fn byte_count(&self) -> i32

pub fn bytes_per_line(&self) -> i32

pub fn valid(&self, x: i32, y: i32) -> bool

pub fn valid_2<P: PointTrait<'a>>(&self, pt: &P) -> bool

pub fn pixel_index(&self, x: i32, y: i32) -> i32

pub fn pixel_index_2<P: PointTrait<'a>>(&self, pt: &P) -> i32

pub fn set_pixel(&self, x: i32, y: i32, index_or_rgb: u32) -> &Self

pub fn set_pixel_2<P: PointTrait<'a>>(&self, pt: &P, index_or_rgb: u32) -> &Self

pub fn pixel_color(&self, x: i32, y: i32) -> Color<'_>

pub fn pixel_color_2<P: PointTrait<'a>>(&self, pt: &P) -> Color<'_>

pub fn set_pixel_color<C: ColorTrait<'a>>(&self, x: i32, y: i32, c: &C) -> &Self

pub fn set_pixel_color_2<C: ColorTrait<'a>, P: PointTrait<'a>>( &self, pt: &P, c: &C) -> &Self

pub fn device_pixel_ratio(&self) -> f32

pub fn set_device_pixel_ratio(&self, scale_factor: f32) -> &Self

pub fn fill(&self, pixel: u32) -> &Self

pub fn fill_2<C: ColorTrait<'a>>(&self, color: &C) -> &Self

pub fn fill_3(&self, color: GlobalColor) -> &Self

pub fn has_alpha_channel(&self) -> bool

pub fn set_alpha_channel<I: ImageTrait<'a>>(&self, alpha_channel: &I) -> &Self

pub fn alpha_channel(&self) -> Image<'_>

pub fn create_alpha_mask(&self, flags: ImageConversionFlags) -> Image<'_>

pub fn create_heuristic_mask(&self, clip_tight: bool) -> Image<'_>

pub fn scaled( &self, w: i32, h: i32, aspect_mode: AspectRatioMode, mode: TransformationMode) -> Image<'_>

pub fn scaled_2<S: SizeTrait<'a>>( &self, s: &S, aspect_mode: AspectRatioMode, mode: TransformationMode) -> Image<'_>

pub fn scaled_to_width(&self, w: i32, mode: TransformationMode) -> Image<'_>

pub fn scaled_to_height(&self, h: i32, mode: TransformationMode) -> Image<'_>

pub fn mirrored(&self, horizontally: bool, vertically: bool) -> Image<'_>

pub fn mirrored_2( &self, horizontally: bool, vertically: bool) -> Option<Image<'_>>

pub fn rgb_swapped(&self) -> Image<'_>

pub fn rgb_swapped_2(&self) -> Option<Image<'_>>

pub fn invert_pixels(&self, arg0: InvertMode) -> &Self

pub fn cache_key(&self) -> i64

pub fn paint_engine(&self) -> Option<PaintEngine<'_>>

pub fn dots_per_meter_x(&self) -> i32

pub fn dots_per_meter_y(&self) -> i32

pub fn set_dots_per_meter_x(&self, arg0: i32) -> &Self

pub fn set_dots_per_meter_y(&self, arg0: i32) -> &Self

pub fn offset(&self) -> Point<'_>

pub fn set_offset<P: PointTrait<'a>>(&self, arg0: &P) -> &Self

pub fn text(&self, key: &str) -> String

pub fn set_text(&self, key: &str, value: &str) -> &Self

pub fn pixel_format(&self) -> PixelFormat<'_>

pub fn to_pixel_format(format: Format) -> PixelFormat<'a>

pub fn build(&self) -> Self

Trait Implementations

impl<'a> Clone for Image<'a>

fn clone(&self) -> Image<'a>

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

impl<'a> ImageTrait<'a> for Image<'a>

impl<'a> PaintDeviceTrait<'a> for Image<'a>

Auto Trait Implementations

impl<'a> !RefUnwindSafe for Image<'a>

impl<'a> !Send for Image<'a>

impl<'a> !Sync for Image<'a>

impl<'a> Unpin for Image<'a>

pub fn convert_to_format(
&self,
f: Format,
flags: ImageConversionFlags
) -> Image<'_>

pub fn convert_to_format_2(
&self,
f: Format,
flags: ImageConversionFlags
) -> Image<'_>

pub fn set_pixel_color_2<C: ColorTrait<'a>, P: PointTrait<'a>>(
&self,
pt: &P,
c: &C
) -> &Self

pub fn scaled(
&self,
w: i32,
h: i32,
aspect_mode: AspectRatioMode,
mode: TransformationMode
) -> Image<'_>

pub fn scaled_2<S: SizeTrait<'a>>(
&self,
s: &S,
aspect_mode: AspectRatioMode,
mode: TransformationMode
) -> Image<'_>

pub fn mirrored_2(
&self,
horizontally: bool,
vertically: bool
) -> Option<Image<'_>>

impl<T> Any for Twhere
T: 'static + ?Sized,

impl<T> Borrow<T> for Twhere
T: ?Sized,

impl<T> BorrowMut<T> for Twhere
T: ?Sized,

impl<T, U> Into<U> for Twhere
U: From<T>,

impl<T> ToOwned for Twhere
T: Clone,

impl<T, U> TryFrom<U> for Twhere
U: Into<T>,

impl<T, U> TryInto<U> for Twhere
U: TryFrom<T>,