Module basic module
  1. front page
  2. Basic module
  3. module gd

module gd

The gd module is a module for image processing. It provides the functions of creating, operating, and storing images, and provides a wealth of color, filter, drawing and other related operations.

Here is a sample code that uses the gd module to create and manipulate an image:

1
2
3
4
5
6
7
8
9
10
var gd = require('gd');

var img = gd.create(440, 240); // create a 440x240 truecolor image

var r = img.colorAllocate(255, 0, 0); // allocate two colors
var b = img.colorAllocate(0, 0, 255);
img.rectangle(40, 40, 50, 50, r); // draw a rectangle
img.filledEllipse(80, 100, 30, 50, b); // fill a ellipse

var data = img.getData(gd.PNG); // save image as PNG data

In this example, we first use the create() method to create a 440x240 TRUECOLOR image, and use the colorAllocate() method to assign two colors, then use the rectangle() method to draw a rectangle, and draw a filled Ellipse, and finally use the getData() method to save the image as binary data in PNG format.

static function

create

Create a new image

1
2
3
static Image gd.create(Integer width,
    Integer height,
    Integer color = gd.TRUECOLOR) async;

Call parameters:

  • width: Integer, specify image width
  • height: Integer, specify the image height
  • color: Integer, specifies the image type, allowed values ​​aregd.TRUECOLORorgd.PALETTE

Return results:

  • Image, returns the successfully created image object

load

Decode image from format data

1
static Image gd.load(Buffer data) async;

Call parameters:

  • data:Buffer, given the decoded image data

Return results:

  • Image, returns the successfully decoded image object

Decode image from stream object

1
static Image gd.load(SeekableStream stm) async;

Call parameters:

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

Return results:

  • Image, returns the successfully decoded image object

Decode an image from the specified file

1
static Image gd.load(String fname) async;

Call parameters:

  • fname: String, specify the file name

Return results:

  • Image, returns the successfully decoded image object

rgb

Generate combined colors from rgb color components

1
2
3
static Integer gd.rgb(Integer red,
    Integer green,
    Integer blue);

Call parameters:

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

Return results:

  • Integer, returns the combined color

rgba

Generate combined colors from rgba color components

1
2
3
4
static Integer gd.rgba(Integer red,
    Integer green,
    Integer blue,
    Number alpha);

Call parameters:

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

Return results:

  • Integer, returns the combined color

hsl

Generate combined colors from hsl color components

1
2
3
static Integer gd.hsl(Number hue,
    Number saturation,
    Number lightness);

Call parameters:

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

Return results:

  • Integer, returns the combined color

hsla

Generate combined colors from hsla color components

1
2
3
4
static Integer gd.hsla(Number hue,
    Number saturation,
    Number lightness,
    Number alpha);

Call parameters:

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

Return results:

  • Integer, returns the combined color

hsb

Generate combined colors from hsb color components

1
2
3
static Integer gd.hsb(Number hue,
    Number saturation,
    Number brightness);

Call parameters:

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

Return results:

  • Integer, returns the combined color

hsba

Generate combined colors from hsba color components

1
2
3
4
static Integer gd.hsba(Number hue,
    Number saturation,
    Number brightness,
    Number alpha);

Call parameters:

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

Return results:

  • Integer, returns the combined color

color

Generate combined colors from string

1
static Integer gd.color(String color);

Call parameters:

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

Return results:

  • Integer, returns the combined color

constant

NONE

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

1
const gd.NONE = 0;

JPEG

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

1
const gd.JPEG = 1;

GIF

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

1
const gd.GIF = 2;

PNG

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

1
const gd.PNG = 3;

TIFF

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

1
const gd.TIFF = 4;

BMP

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

1
const gd.BMP = 5;

WEBP

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

1
const gd.WEBP = 6;

TRUECOLOR

Image type constant, indicating that the current image is a true color image

1
const gd.TRUECOLOR = 0;

PALETTE

Image type constant, indicating that the current image is a palette image

1
const gd.PALETTE = 1;

ARC

Sector drawing style, draws an arc connecting the start and end points

1
const gd.ARC = 0;

CHORD

Sector drawing style, draw a straight line connecting the origin, start and end points

1
const gd.CHORD = 1;

NOFILL

Sector drawing style, draws a sector without filling

1
const gd.NOFILL = 2;

EDGED

Sector drawing style, draw an arc connecting the starting point and the end point and a straight line connecting the origin

1
const gd.EDGED = 4;

HORIZONTAL

Mirroring direction, horizontal mirroring processing

1
const gd.HORIZONTAL = 1;

VERTICAL

Mirror direction, vertical mirror processing

1
const gd.VERTICAL = 2;

BOTH

Mirroring direction, both horizontal and vertical mirroring processing

1
const gd.BOTH = 3;

LEFT

Rotation direction, rotate left

1
const gd.LEFT = 1;

Rotation direction, rotate right

1
const gd.RIGHT = 2;

MEAN_REMOVAL

Filter type: Use average removal method to achieve contour effect

1
const gd.MEAN_REMOVAL = 0;

EDGEDETECT

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

1
const gd.EDGEDETECT = 1;

EMBOSS

Filter type: Emboss image

1
const gd.EMBOSS = 2;

SELECTIVE_BLUR

Filter Type: Blur Image

1
const gd.SELECTIVE_BLUR = 3;

GAUSSIAN_BLUR

Filter type: Blur image with Gaussian algorithm

1
const gd.GAUSSIAN_BLUR = 4;

NEGATE

Filter type: Invert all colors in the image

1
const gd.NEGATE = 5;

GRAYSCALE

Filter type: Convert image to grayscale

1
const gd.GRAYSCALE = 6;

SMOOTH

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

1
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

1
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

1
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 value returned is 0~127.

1
const gd.COLORIZE = 10;
© Copyright 2012-2024 fibjs.org | Support us