image #

##Overview

A Dart library to encode and decode various image formats.

The library has no reliance on dart:io, so it can be used for both server and web applications. The image library currently supports the following formats:

• PNG
• JPG
• TGA

##Samples

Load a jpeg, resize it, and save it as a png:

import 'dart:io' as Io;
import 'package:image/image.dart';
void main() {
  // Read a jpeg image from file.
  Image image = readJpg(new Io.File('res/cat-eye04.jpg').readAsBytesSync());

  // Resize the image to a 120x? thumbnail (maintaining the aspect ratio).
  Image thumbnail = copyResize(image, 120);

  // Save the thumbnail as a PNG.
  new Io.File('out/thumbnail-cat-eye04.png')
        ..createSync(recursive: true)
        ..writeAsBytesSync(writePng(thumbnail));
}

Create an image, draw some text, save it as a png:

import 'dart:io' as Io;
import 'package:image/image.dart';
void main() {
  // Create an image
  Image image = new Image(320, 240);
  
  // Fill it with a solid color (blue)
  fill(image, getColor(0, 0, 255));
  
  // Draw some text using 24pt arial font
  drawString(image, arial_24, 0, 0, 'Hello World');
  
  // Draw a line
  drawLine(image, 0, 0, 320, 240, getColor(255, 0, 0), thickness: 3);
  
  // Blur the image
  gaussianBlur(image, 10);
  
  // Generate a PNG
  List<int> png = writePng(image);
  
  // Save it to disk
  new Io.File('out/test.png')
        ..createSync(recursive: true)
        ..writeAsBytesSync(png);
}

##Image Functions

• Image brightness(Image src, int brightness);

  Adjust the brightness of the image.

• Image bumpToNormal(Image src, {double strength: 2.0});

  Generate a normal map from a heightfield bump image.

• Image colorOffset(Image src, int red, int green, int blue, int alpha);

  Apply an offset to the colors of the image.

• Image contrast(Image src, num contrast);

  Apply the Contrast convolution filter to the image.

• Image convolution(Image src, List

  Apply a convolution filter to the image.

• Image copyCrop(Image src, int x, int y, int w, int h);

  Create a cropped copy of the image.

• Image copyInto(Image dst, Image src, [int dst_x, int dst_y, int src_x, int src_y, int dst_w, int dst_h, int src_w, int src_h]);

  Copy an area of the src image into dst.

• Image copyResize(Image src, int width, [int height = -1, int interpolation = LINEAR]);

  Create a resized copy of the image.

• Image copyRotate(Image src, num angle, {int interpolation: LINEAR}) {

  Returns a copy of the [src] image, rotated by [angle] degrees.

• Image drawChar(Image image, BitmapFont font, int x, int y, String string, {int color: 0xffffffff});

  Draw a single character with the given font.

• Image drawCircle(Image image, int x0, int y0, int radius, int color);

  Draw a circle.

• Image drawLine(Image image, int x1, int y1, int x2, int y2, int color, {bool antialias: false, num thickness: 1});

  Draw a line.

• Image drawNoise(Image image, double sigma, {int type: NOISE_GAUSSIAN, Math.Random random});

  Add random noise to pixel values.

• Image drawPixel(Image image, int x, int y, int color, [int opacity = 0xff]);

  Draw a single pixel into the image, applying alpha and opacity blending.

• Image drawString(Image image, BitmapFont font, int x, int y, String string, {int color: 0xffffffff});

  Draw the string with the given font.

• Image dropShadow(Image src, int hshadow, int vshadow, int blur, {int shadowColor: 0x000000a0});

  Create a drop-shadow effect.

• Image emboss(Image src);

  Apply the Emboss convolution filter.

• Image fill(Image image, int color);

  Fill the image with the given color.

• Image fillRect(Image src, int x1, int y1, int x2, int y2, int color);

  Fill a rectangle with the given color.

• Image flip(Image src, int mode);

  Flip the image with FLIP_HORIZONTAL, FLIP_VERTICAL, or FLIP_BOTH.

• Image gaussianBlur(Image src, int radius);

  Blur the image.

• Image grayscale(Image src);

  Convert the colors of the image to grayscale.

• Image invert(Image src);

  Inver the colors of the image.

• Image normalize(Image src, int minValue, int maxValue);

  Linearly normalize the pixel values of the image.

• Image pixelate(Image src, int blockSize, {int mode: PIXELATE_UPPERLEFT});

  Pixelate the image.

• BitmapFont readFontZip(List

  Load a BitmapFont from a zip file.

• BitmapFont readFont(String fnt, Image page);

  Load a BitmapFont from a font file and image.

• Image readJpg(List

  Load an Image from JPG formatted data.

• Image readPng(List

  Load an Image from PNG formatted data.

• Image readTga(List

  Load an Image from TGA formatted data.

• Image remapColors(Image src, {int red: RED, int green: GREEN, int blue: BLUE, int alpha: ALPHA});

  Remap the color channels of an image.

• Image smooth(Image src, num w);

  Apply a smooth convolution filter to the image.

• List

  Generate JPG formatted data for the given image.

• List

  Generate PNG formatted data for the given image.

• List

  Generate TGA formatted data for the given image.