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JPEG decoder for .NET Core

there is currently no "built in" JPEG decoder class for .NET Core since System.Drawing (except for System.Drawing.Primitives) is currently not present as a nuget package.
I do understand that System.Drawing relies on underlying Win32 GDI code which obviously is not present on all platforms.
I did read some posts about possible implementations and there appear to be some alpha-grade JPEG packages on nuget but I haven't been able to find a proper one.
Does anyone know about a simple way of DECODING JPEG pictures on .NET Core for some server side processing? I don't even need resize or other functions, decoding would suffice perfectly.
Help is greatly appreciated.
Thanks in advance!
-Simon

Have a look at https://github.com/JimBobSquarePants/ImageSharp
With a usage like in these samples:
Sample 1:
// resizing and filter (grayscale)
using (FileStream stream = File.OpenRead("foo.jpg"))
using (FileStream output = File.OpenWrite("bar.jpg"))
{
Image image = new Image(stream);
image.Resize(image.Width / 2, image.Height / 2)
.Grayscale()
.Save(output);
}
Sample 2: Accessing Pixels
Image image = new Image(400, 400);
using (PixelAccessor<Color, uint> pixels = image.Lock())
{
pixels[200, 200] = Color.White;
}

There is an ImageMagick wrapper for .net which looks like it now supports .Net Core: https://magick.codeplex.com

I have also found the following which works like a charm and is extremely slim: https://www.nuget.org/packages/BitMiracle.LibJpeg.NET/

Resize image on the fly in .net and c#

I'm looking for a way to resize images without saving them on the server. The ways that i have found includes a controller file and such.
Is there a way to get the image from the stream, resize it and add it to the response?

Check out ImageResizer - it's a suite of NuGet packages designed for this exact purpose.
It runs eBay in Denmark, MSN Olympics, and a few other big sites.
Dynamic image processing can be done safely and efficiently, but not in a sane amount of code. It's trickier than it appears.

I wouldn't recommend this but you can do next thing:
using (Image img = Image.FromStream(originalImage))
{
using (Bitmap bitmap = new Bitmap(img, width, height))
{
bitmap.Save(outputStream, ImageFormat.Jpeg);
}
}
Be aware that this could cause OutOfMemoryException.

Place Image from DLL onto a web page

I'm so stuck on something i thought would be easy.
I have a DLL that returns an Image object.
I just cant figure out how to display that image on a webpage.
I've tried a few ways, and google a million different variations.
Is it not possible to just bind an Image object to an element on the page like an HtmlImage or a simple img?
Or do i need to convert the Image to a Stream? or a Bitmap? I'm really stuck!
Any help appreciated.....
V

With Asp.Net WebForm, the easiest way is to create a custom ashx file.
In Visual Studio, create a new Custom Handler (I'm not sure of the name of the template in Visual Studio). This will create a .ashx file.
In the code of this handler, write something like (does not have VS under the hand to test the syntax) :
public void ProcessRequest(System.Web.HttpContext context)
{
byte[] raw;
using(var ms = new MemoryStream()){
Image myImage = GetFromDll();
myImage.Save(ms, ImageFormat.Png);
raw=ms.ToArray();
}
context.Response.ContentType = "image/png";
context.Response.BinaryWrite(raw);
}
Then, in your browser, navigate to http://yourserver/app/yourhandler.ashx.
You can if you want add url parameter, and get it from the Request.QueryString collection

It's not as simple as binding. On the client side images are retrieved from the web server as a separate GET request, which means you have to have a URL that resolves to an image. The other option, as Asif suggested, is embedding your image in the HTML as a Base64 string, which is bad practice for shared images (see Steve B's comment).
You either have to provide an URL (route that returns the image file in MVC, or a custom page with proper content type and Response.Write in WebForms), or embed in html.
EDIT:
There is also a third option involving custom HTTP handlers. These have the advantage of bypassing the app framework and serving the content almost directly off the web server, see MSDN.

Convert your image to base64 string and then set it in the <img/> tag.
<img/> can show the image in base64 string.
Alternatively you can save the image and use the path in the <img/>.

convert bitmap to image c# [duplicate]

this is how my code look now:
System.Drawing.Image objImage = System.Drawing.Image.FromFile(Server.MapPath("aaa.jpg"));
int height = objImage.Height;
int width = objImage.Width;
System.Drawing.Bitmap bitmapimage = new System.Drawing.Bitmap(objImage, width, height);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmapimage);
System.Drawing.Image bitmap2 = (System.Drawing.Image)Bitmap.FromFile(Server.MapPath("sem.png"));
g.DrawImage(bitmap2, (objImage.Width - bitmap2.Width) / 2, (objImage.Height - bitmap2.Height) / 2);
MemoryStream stream = new MemoryStream();
bitmapimage.Save(stream, ImageFormat.Jpeg);
String saveImagePath = Server.MapPath("ImagesMerge/") + "aaa.jpg";
bitmapimage.Save(saveImagePath);
imgBig.ImageUrl = saveImagePath;
The problem I have now is that the image is not displayed in browser, I don't understand why .

like jmaglasang said, I would suggest to you to use an ashx file and if you don't need to keep the image, just send the image stream directly to the http without saving it on the disk
so you only need to do something like
<img src="Handler.ashx?action=merge&image1=blah.jpg&image2=bloh.jpg">
look at this code for an example of how to send an image made in memory that does not exist on the drive

Bitmap is a subclass of Image, so there no need to convert Bitmap to Image. It already is...

Probably because saveImagePath will be a local path (such as c:\somepath\aaa.jpg) that is not reachable from the browser. You probably want to set the ImageUrl = "ImagesMerge/aaa.jpg" instead.

You can also try:
imgBig.ImageUrl = ResolveUrl(saveImagePath);
EDIT:
If saveImagePath is under the WebApplication Directory, doing some modifications on the directory structure i.e. modifying files, deleting and creating can cause the application pool to recycle, and once it reaches the maximum recycle count the application pool will be stopped causing "Server unavailable" error.
I would suggests to add/save/modify images on a separate directory (not under the Apps Directory) then create a Handler(ASHX) that will read the images, just an advice though.

MapPath will give you a physycal address, not a virtual address which is what the browser needs to get to the image.

You might be forgetting to set the Response.Headers. Check out the following example that shows how to create bar chart images and then display it on the screen:
http://www.highoncoding.com/Articles/399_Creating_Bar_Chart_Using__NET_Graphics_API.aspx

Reading PSD file format

I wonder if this is even possible. I have an application that adds a context menu when you right click a file. It all works fine but here is what I'd like to do:
If the file is a PSD then I want the program to extract the image. Is this possible to do without having Photoshop installed?
Basically I want the user to right click and click "image" which would save a .jpg of the file for them.
edit: will be using c#
Thanks

The ImageMagick libraries (which provide bindings for C#) also support the PSD format. They might be easier to get started with than getting into the Paint.NET code and also come with a quite free (BSD-like) license.
A simple sample (found at http://midimick.com/magicknet/magickDoc.html) using MagickNet would look like this:
using System;
static void Main(string[] args)
{
MagickNet.Magick.Init();
MagicNet.Image img = new MagicNet.Image("file.psd");
img.Resize(System.Drawing.Size(100,100));
img.Write("newFile.png");
MagickNet.Magick.Term();
}
Note: MagickNet has moved to http://www.codeproject.com/KB/dotnet/ImageMagick_in_VBNET.aspx

Well, there's a PSD plugin for Paint.NET which I think is Open-Source which you might want to take a look at for starters:
http://frankblumenberg.de/doku/doku.php?id=paintnet:psdplugin#download

This guy do it easier:
http://www.codeproject.com/KB/graphics/simplepsd.aspx
With a C# library and a sample project.
I've tried with PS2 files and works ok.

I have written a PSD parser which extracts raster format layers from all versions of PSD and PSB. http://www.telegraphics.com.au/svn/psdparse/trunk

You can use GroupDocs.Viewer for .NET API to render your PSD files as images (JPG, PNG, BMP) in your application using a few lines of code.
C#
ViewerConfig config = new ViewerConfig();
config.StoragePath = "D:\\storage\\";
// Create handler
ViewerImageHandler imageHandler = new ViewerImageHandler(config);
// Guid implies that unique document name
string guid = "sample.psd";
// Get document pages as images
List<PageImage> pages = imageHandler.GetPages(guid);
foreach (PageImage page in pages)
{
// Access each image using page.Stream
}
For more details and sample code, please visit here.
Disclosure: I work as a Developer Evangelist at GroupDocs.

For people who are reading this now: the link from accepted answer doesn't seem to work anymore (at least for me). Would add a comment there, but not allowed to comment yet - hence I'm adding a new answer.
The working link where you can find the psdplugin code for Paint.Net: https://github.com/PsdPlugin/PsdPlugin

Here is my own psd parser and exporter:
http://papirosnik.info/psdsplit/.
It allows to correctly parse psd with rgb color 8, 16- and 32-bit for channel, process user masks, export selected layers into jpeg, png, jng, bmp, tiff; create xml layout of exported layers and groups and also create a texture atlas and animations set from given layers.
It's entirely written in C#. If you want its sources inform me via support link on About dialog in the application.

ImageMagick.NET - http://imagemagick.codeplex.com/ - is the later version of the link 0xA3 gave, with some slightly different syntax. (Note, this is untested):
using ImageMagickNET;
public void Test() {
MagickNet.InitializeMagick();
ImageMagickNET.Image img = new ImageMagickNET.Image("file.psd");
img.Resize(new Geometry(100, 100, 0, 0, false, false);
img.Write("newFile.png");
}

I got extraction from psd working. see my answer here
How to extract layers from a Photoshop file? C#
may help someone else.

FastStone does this pretty efficiently.
They do not have their libraries availaible, but I guess you can contact them and see if they can help.
Check out their website: http://www.faststone.org/download.htm

I've had great success with Aspose's Imaging component which can load and save PSD files without Photoshop: https://products.aspose.com/imaging/net