Get started using .NET Image Library

Create a new image

There are two methods for creating a new empty image; KalikoImage(int width, int height) will create a transparent image in the specified size while KalikoImage(int width, int height, Color bgcolor) will create an image filled with the color past as the last parameter.

    // Creating a new transparent image
    var image = new KalikoImage(640, 480);

    // Creating a white image
    var image = new KalikoImage(640, 480, Color.White);

Load an image

Images can be loaded from the file system, the web or streams. The easiest way to load an image is to use the corresponding constructor.

    // Open image from file system
    var image = new KalikoImage(@"C:\MyImages\Image.png");

    // Open image from URL
    var image = new KalikoImage(@"http://www.mysite.domain/myimage.jpg");

    // Open image from a stream
    MemoryStream memoryStream = ...
    var image = new KalikoImage(memoryStream);

Save an image

Images can be saved in several formats, either to the file system or as streams. In addition to format specific methods (such as SaveJpg(string fileName, long quality)) there's a generic save function that takes an ImageFormat as a parameter which controls the format the image will be saved in.

    // Save image to file system in the selected format
    image.SaveImage(@"C:\MyImages\Output.tif", ImageFormat.Tiff);

Saving in JPEG format

The following methods are available for saving images in JPEG format: StreamJpg(long quality, string fileName) (write image as HttpResponse), SaveJpg(Stream stream, long quality) and SaveJpg(string fileName, long quality). Quality parameter is given as a number between 1 and 100 where higher is better quality but also larger file size.

Here's a couple of samples of saving images in JPEG format:

    // Save image to file system in jpg format with quality setting 90
    image.SaveJpg(@"C:\MyImages\Output.jpg", 90);
            
    // Save image to stream in jpg format with quality setting 90
    MemoryStream memoryStream = new MemoryStream();
    image.SaveJpg(memoryStream, 90);

    // Send the image in jpg format as a HttpResponse with quality setting 80
    image.StreamJpg(80, "MyImage.jpg");

Saving in BMP format

The following methods are available for saving images in BMP format: SaveBmp(Stream stream), SaveBmp(string fileName) and SaveBmp(Stream stream, ImageFormat format)

Saving in GIF format

The following methods are available for saving images in GIF format: StreamGif(string fileName) (write image as HttpResponse), SaveGif(Stream stream) and SaveGif(string fileName)

Saving in PNG format

The following methods are available for saving images in PNG format: SavePng(Stream stream, long quality)* and SavePng(string fileName, long quality)* (* please ignore the quality parameter for the PNG related methods.)

Blitting and image filling

There are two ways to place one image into another. Either by using BlitImage that will take the source image and place it on the destination image at the given coordinates or by using BlitFill that will use the source image as a pattern and fill the complete destination image - tiled if necessary.

Blitting an image

    // Place the source image on top, left of our image
    var sourceImage = new KalikoImage(@"C:\Img\Stamp.png");
    image.BlitImage(sourceImage, 0, 0);

    // Repeat the above, but in a single call
    image.BlitImage(@"C:\Img\Stamp.png", 0, 0);

Blitt fill an image

    // Create a new image and fill the source image all over
    var image = new KalikoImage(640, 480);
    var patternImage = new KalikoImage(@"C:\Img\Checkered.png");
    image.BlitFill(patternImage);

    // Repeat the above, but in a just one additional call
    var image = new KalikoImage(640, 480);
    image.BlitFill(@"C:\Img\Checkered.png");

Image resolution

Original resolution is stored when loading an image, but in order to save the resolution with the image the saveResolution parameter in the save function needs to be set to true. If not set or set to false the image will be saved with screen resolution (96 DPI).

    var image = new KalikoImage("image.jpg");
    image.SaveJpg("image-keep-dpi.jpg", 90, true);

It's also possible to get or set the current resolution by using the HorizontalResolution and VerticalResolution properties.

    var image = new KalikoImage("image.jpg");
    image.VerticalResolution = 300;
    image.HorizontalResolution = 300;
    image.SaveJpg("image-300-dpi.jpg", 90, true);

Image dimensions

There are three properties to check the ratio of the image, these are IsLandscape, IsPortrait and IsSquare.

Use Resize(int width, int height) in order to resize the image into the given width and height - not taking the ratio in between in consideration.

If you want to resize the image but also make sure that it keeps its ratio, then the GetThumbnailImage(int width, int height, ThumbnailMethod method) function should be used. There are three different ways; ThumbnailMethod.Crop that will fill the complete given dimensions which might lead to cropping, ThumbnailMethod.Fit that will fit the entire image within the given dimensions and ThumbnailMethod.Pad that will fit the entire image within the given dimensions and pad with background color to full dimension if needed.

For more information about creating thumbnails check this tutorial .

Writing text

This library supports writing text onto images. This is done through the functions SetFont(string fileName, float size, FontStyle fontStyle) that sets the font to use, WriteText(string txt, int x, int y) to render the text onto the image and WriteText(string txt, int x, int y, float angle) that renders the text but in any angle.

    // Write Hello World on image with semi transparent white
    var image = new KalikoImage(@"C:\Img\MyImage.jpg");

    // Load the font, relative path from the application path
    image.SetFont("84_rock.ttf", 120, FontStyle.Regular);
    image.Color = Color.FromArgb(64, Color.White);
    image.WriteText("Hello World!", 0, 0);