Module basic module

Module gd

Image file processing module

Basic module. Can be used to create and manipulate image files, reference method:

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var gd = require('gd');

Static function

create

Create a new image

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static Image gd.create(Integer width, Integer height, Integer color = gd.TRUECOLOR) async;

Call parameters:

  • width : Integer, specify the image width
  • height : Integer, specify the image height
  • color : Integer, specify image type, allowed value is gd.TRUECOLOR or gd.PALETTE

Return result:

  • Image , returns the successfully created image object

load

Decode image from format data

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static Image gd.load(Buffer data) async;

Call parameters:

  • data : Buffer , given decoded image data

Return result:

  • Image , returns the successfully decoded image object

Decode image from stream object

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static Image gd.load(SeekableStream stm) async;

Call parameters:

  • stm : SeekableStream , the stream object where the given image data is located

Return result:

  • Image , returns the successfully decoded image object

Decode image from specified file

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static Image gd.load(String fname) async;

Call parameters:

  • fname : String, specify the file name

Return result:

  • Image , returns the successfully decoded image object

rgb

Generate combined colors from rgb color components

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static Integer gd.rgb(Integer red, Integer green, Integer blue);

Call parameters:

  • red : Integer, the red component, the range is 0-255
  • green : Integer, the green component, the range is 0-255
  • blue : Integer, the blue component, the range is 0-255

Return result:

  • Integer , returns the combined color

rgba

Generate combined colors from rgba color components

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static Integer gd.rgba(Integer red, Integer green, Integer blue, Number alpha);

Call parameters:

  • red : Integer, the red component, the range is 0-255
  • green : Integer, the green component, the range is 0-255
  • blue : Integer, the blue component, the range is 0-255
  • alpha : Number, the transparency component, the range is 0.0-1.0

Return result:

  • Integer , returns the combined color

hsl

Generate combined colors from hsl color components

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static Integer gd.hsl(Number hue, Number saturation, Number lightness);

Call parameters:

  • hue : Number, hue component, the range is 0-360
  • saturation : Number, the saturation component, the range is 0.0-1.0
  • lightness : Number, the brightness component, the range is 0.0-1.0

Return result:

  • Integer , returns the combined color

hsla

Generate combined colors from hsla color components

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static Integer gd.hsla(Number hue, Number saturation, Number lightness, Number alpha);

Call parameters:

  • hue : Number, hue component, the range is 0-360
  • saturation : Number, the saturation component, the range is 0.0-1.0
  • lightness : Number, the brightness component, the range is 0.0-1.0
  • alpha : Number, the transparency component, the range is 0.0-1.0

Return result:

  • Integer , returns the combined color

hsb

Generate combined colors from hsb color components

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static Integer gd.hsb(Number hue, Number saturation, Number brightness);

Call parameters:

  • hue : Number, hue component, the range is 0-360
  • saturation : Number, the saturation component, the range is 0.0-1.0
  • brightness : Number, the brightness component, the range is 0.0-1.0

Return result:

  • Integer , returns the combined color

hsba

Generate combined colors from hsba color components

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static Integer gd.hsba(Number hue, Number saturation, Number brightness, Number alpha);

Call parameters:

  • hue : Number, hue component, the range is 0-360
  • saturation : Number, the saturation component, the range is 0.0-1.0
  • brightness : Number, the brightness component, the range is 0.0-1.0
  • alpha : Number, the transparency component, the range is 0.0-1.0

Return result:

  • Integer , returns the combined color

color

Generate combined colors from strings

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static Integer gd.color(String color);

Call parameters:

  • color : String, a string specifying the color, such as: "#ff0000", "ff0000", "#f00", "f00"

Return result:

  • Integer , returns the combined color

constant

NONE

Image format constant, indicating that the source of the current image is unknown

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const gd.NONE = 0;

JPEG

Image format constant, indicating that the current image source is jpeg format data

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const gd.JPEG = 1;

GIF

Image format constant, indicating that the current image source is gif format data

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const gd.GIF = 2;

PNG

Image format constant, indicating that the current image source is png format data

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const gd.PNG = 3;

TIFF

Image format constant, indicating that the current image source is tiff format data

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const gd.TIFF = 4;

BMP

Image format constant, indicating that the current image source is bmp format data

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const gd.BMP = 5;

WEBP

Image format constant, indicating that the current image source is webp format data

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const gd.WEBP = 6;

TRUECOLOR

Image type constant, marking the current image as a true color image

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const gd.TRUECOLOR = 0;

PALETTE

Image type constant, marking the current image as a palette image

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const gd.PALETTE = 1;

ARC

Fan-shaped drawing style, draw an arc connecting the start and end points

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const gd.ARC = 0;

CHORD

Fan-shaped drawing style, draw a straight line connecting the origin, start and end points

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const gd.CHORD = 1;

NOFILL

Fan drawing style, draw a fan without filling

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const gd.NOFILL = 2;

EDGED

Fan-shaped drawing style, draw an arc connecting the start and end points and a straight line connecting the origin

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const gd.EDGED = 4;

HORIZONTAL

Mirror direction, horizontal mirror processing

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const gd.HORIZONTAL = 1;

VERTICAL

Mirror direction, mirror image processing vertically

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const gd.VERTICAL = 2;

BOTH

Mirror direction, both horizontal and vertical mirror processing

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const gd.BOTH = 3;

LEFT

Rotation direction, rotate left

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const gd.LEFT = 1;

Rotation direction, rotate right

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const gd.RIGHT = 2;

MEAN_REMOVAL

Filter type: use average removal method to achieve contour effect

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const gd.MEAN_REMOVAL = 0;

EDGEDETECT

Filter type: use edge detection to highlight the edges of the image

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const gd.EDGEDETECT = 1;

EMBOSS

Filter type: emboss the image

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const gd.EMBOSS = 2;

SELECTIVE_BLUR

Filter type: Blurred image

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const gd.SELECTIVE_BLUR = 3;

GAUSSIAN_BLUR

Filter type: Blur image using Gaussian algorithm

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const gd.GAUSSIAN_BLUR = 4;

NEGATE

Filter type: invert all colors in the image

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const gd.NEGATE = 5;

GRAYSCALE

Filter type: Convert the image to grayscale

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const gd.GRAYSCALE = 6;

SMOOTH

Filter type: make the image smoother, use arg1 to set the smoothness level

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const gd.SMOOTH = 7;

BRIGHTNESS

Filter type: change the brightness of the image, use arg1 to set the brightness level, the value range is -255~255

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const gd.BRIGHTNESS = 8;

CONTRAST

Filter type: change the contrast of the image, use arg1 to set the contrast level, the value range is 0~100

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const gd.CONTRAST = 9;

COLORIZE

Filter type: change the hue of the image, use arg1, arg2, and arg3 to specify red, blue, and green respectively. The range of each color is 0~255, arg4 is transparency, and the return value is 0~127

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const gd.COLORIZE = 10;