Image class
An image buffer where pixels are encoded into 32-bit unsigned ints (Uint32).
Pixels are stored in 32-bit unsigned integers in #AARRGGBB format. This is to be consistent with the Flutter image data. You can use getBytes to access the pixel data at the byte (channel) level, optionally providing the format to get the image data as. You can use the various color functions, such as getRed, getGreen, getBlue, and getAlpha to access the individual channels of a given pixel color.
If this image is a frame of an animation as decoded by the decodeFrame
method of Decoder, then the xOffset, yOffset, width and height
determine the area of the canvas this image should be drawn into,
as some frames of an animation only modify part of the canvas (recording
the part of the frame that actually changes). The decodeAnimation method
will always return the fully composed animation, so these coordinate
properties are not used.
Constructors
-
Image(int width, int height, {Channels channels = Channels.rgba, ExifData? exif, ICCProfileData? iccp, Map<
String, String> ? textData}) - Create an image with the given dimensions and format.
- Image.from(Image other)
-
Create a copy of the image
other. -
Image.fromBytes(int width, int height, List<
int> bytes, {ExifData? exif, ICCProfileData? iccp, Format format = Format.rgba, Channels channels = Channels.rgba, Map<String, String> ? textData}) -
Create an image from raw data in
bytes. -
Image.rgb(int width, int height, {ExifData? exif, ICCProfileData? iccp, Map<
String, String> ? textData}) - Create an image with the given dimensions and format.
Properties
- blendMethod ↔ BlendMode
-
Defines the blending method (alpha compositing) to use when drawing this
frame in an animation.
getter/setter pair
- channels ↔ Channels
-
The channels used by this image, indicating whether the alpha channel
is used or not. All images have an implicit alpha channel due to the
image data being stored in a Uint32, but some images, such as those
decoded from a Jpeg, don't use the alpha channel. This allows
image encoders that support both rgb and rgba formats, to know which
one it should use.
getter/setter pair
- data → Uint32List
-
Pixels are encoded into 4-byte Uint32 integers in #AABBGGRR channel order.
final
- disposeMethod ↔ DisposeMode
-
Defines what should be done to the canvas when drawing this frame
in an animation.
getter/setter pair
- duration ↔ int
-
How long this frame should be displayed, in milliseconds.
A duration of 0 indicates no delay and the next frame will be drawn
as quickly as it can.
getter/setter pair
- exif ↔ ExifData
-
EXIF data decoded from an image file.
getter/setter pair
- hashCode → int
-
The hash code for this object.
no setterinherited
- height → int
-
Height of the image.
final
- iccProfile ↔ ICCProfileData?
-
ICC color profile read from an image file.
getter/setter pair
- length → int
-
The size of the image buffer.
no setter
- numberOfChannels → int
-
The number of channels used by this Image. While all images
are stored internally with 4 bytes, some images, such as those
loaded from a Jpeg, don't use the 4th (alpha) channel.
no setter
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
-
textData
↔ Map<
String, String> ? -
Some formats, like PNG, can encode and decode text data with the image.
getter/setter pair
- width → int
-
Width of the image.
final
- xOffset ↔ int
-
x position at which to render the frame. This is used for frames
in an animation, such as from an animated GIF.
getter/setter pair
- yOffset ↔ int
-
y position at which to render the frame. This is used for frames
in an animation, such as from an animated GIF.
getter/setter pair
Methods
-
addTextData(
Map< String, String> data) → void -
boundsSafe(
int x, int y) → bool -
Is the given
x,ypixel coordinates within the resolution of the image. -
clone(
) → Image - Clone this image.
-
fill(
int color) → Image -
Set all of the pixels of the image to the given
color. -
fillBackground(
int color) → void -
Set all of the empty pixels (for png's) of the image to the given
color. -
getBytes(
{Format format = Format.rgba}) → Uint8List - Get the bytes from the image. You can use this to access the color channels directly, or to pass it to something like an Html canvas context.
-
getPixel(
int x, int y) → int -
Get the pixel from the given
x,ycoordinate. Color is encoded in a Uint32 as #AABBGGRR. No range checking is done. -
getPixelCubic(
num fx, num fy) → int - Get the pixel using cubic interpolation for non-integer pixel coordinates.
-
getPixelInterpolate(
num fx, num fy, [Interpolation interpolation = Interpolation.linear]) → int -
Get the pixel using the given
interpolationtype for non-integer pixel coordinates. -
getPixelLinear(
num fx, num fy) → int - Get the pixel using linear interpolation for non-integer pixel coordinates.
-
getPixelSafe(
int x, int y) → int -
Get the pixel from the given
x,ycoordinate. Color is encoded in a Uint32 as #AABBGGRR. If the pixel coordinates are out of bounds, 0 is returned. -
getWhiteBalance(
{bool asDouble = false}) → dynamic - Return the average gray value of the image.
-
index(
int x, int y) → int -
Get the buffer index for the
x,ypixel coordinates. No range checking is done. -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
setPixel(
int x, int y, int color) → void -
Set the pixel at the given
x,ycoordinate to thecolor. No range checking is done. -
setPixelRgba(
int x, int y, int r, int g, int b, [int a = 0xff]) → void -
Set the pixel at the given
x,ycoordinate to the colorr,g,b,a. -
setPixelSafe(
int x, int y, int color) → void -
Set the pixel at the given
x,ycoordinate to thecolor. If the pixel coordinates are out of bounds, nothing is done. -
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator %(
Image other) → Image -
Modula the colors of
otherwith the pixels of this image. -
operator &(
Image other) → Image -
AND the colors of
otherwith the pixels of this image. -
operator *(
Image other) → Image -
Multiply the colors of
otherwith the pixels of this image. -
operator +(
Image other) → Image -
Add the colors of
otherto the pixels of this image. -
operator -(
Image other) → Image -
Subtract the colors of
otherfrom the pixels of this image. -
operator ==(
Object other) → bool -
The equality operator.
inherited
-
operator [](
int index) → int - Get a pixel from the buffer. No range checking is done.
-
operator []=(
int index, int color) → void - Set a pixel in the buffer. No range checking is done.
-
operator |(
Image other) → Image -
OR the colors of
otherto the pixels of this image.