Develop Reference

C# - Convert JBIG1 images to other image formats

I need to convert a JBIG1 image to another image format, such as JPEG or PNG, but I can't seem to find anything related to this.
This JBIG1 image is received encoded in Base64.
I've tried using System.Drawing in .NET to accomplish this, but a "System.ArgumentException: Parameter is not valid" exception is thrown on calling Image.FromStream() using the JBIG1 byte array data.
See code below:
byte[] binData = ConvertFromBase64StringToArray("BASE64 ENCODED JBIG1 IMAGE GOES HERE");
Image img = binData.ConvertToImage();
img.Save("C:/Images/converted-from-jbig.jpeg", System.Drawing.Imaging.ImageFormat.Jpeg);
Functions used:
public static byte[] ConvertFromBase64StringToArray(string base64String)
{
byte[] data = Convert.FromBase64String(base64String);
using (var stream = new MemoryStream(data, 0, data.Length))
{
data = stream.ToArray();
}
return data;
}
public static Image ConvertToImage(this byte[] byteArrayIn)
{
var ms = new MemoryStream(byteArrayIn);
Image returnImage = Image.FromStream(ms); //exception thrown in this line
return returnImage;
}
Does anyone have any knowledge to share about this topic?

You'll probably need a third party library to work with JBig files. It looks like https://github.com/dlemstra/Magick.NET has support for that.

Getting error from the inkcanvase base 64 string

Hello we are using InkCanvas control on the wpf page. And we are saving Base64String string in the database. See code
private void submitButtonsCommand_Event(object sender)
{
byte[] sigByte;
InkCanvas icSignature = sender as InkCanvas;
using (var memoryStream = new MemoryStream())
{
icSignature.Strokes.Save(memoryStream);
sigByte = memoryStream.ToArray();
}
ServiceCallReportSignatureModel.SigCustomerSignature = Convert.ToBase64String(sigByte);
UpdateRecord();
}
And when we are retrieving data from the database and converting into the FromBase64String and after that when we creating image then we are getting the error.
public Image LoadImage(base64string)
{
//data:image/gif;base64,
//this image is a single pixel (black)
byte[] bytes = Convert.FromBase64String(base64string);
Image image;
using (MemoryStream ms = new MemoryStream(bytes))
{
image = Image.FromStream(ms);
}
return image;
}
I don't know why this is occurring. Please help me find out the error.
Our base64 string is : "AIwBAwxIEEWfARsCAAb/RjURAACAPx8JEQAAAAAAAPA/Cmwsh/EgR4kP+Etw/ojDWG7NZ8OZQxBN5otEzmU1mk04I7DnATcLHomzzUbxw/h3Dtp16yhlTQ2UsoTQh+uE64XgjsN6Js2UZpAZmFpmaZTKzzKZ4ctFmw3Mlmm0Bw9h/DtpTPKu79CYgm+VJqA="
Actually we are taking signature from the ink canvas control and we want to display in the pdf when we need. So we want create image from the base 64 data but we are getting the error.

The StrokeCollection.Save(Stream) method does not save a bitmap. Instead,
The Save method saves the StrokeCollection as Ink Serialized Format (ISF).
You can restore the saved StrokeCollection by passing a Stream with the saved data to the StrokeCollection(Stream) constructor.

Getting an image path to use in converting to base 64 string

I have an image in my images folder
and I want to pass this image to an Image object so I can then convert it to a base 64 string. This will then be passed to the client and inserted into the src of a img element.
The problem is that I don't know how to get the image from disk into the image object.
Image img = Image.FromFile(#"..Images\no_image.jpg"); // doesn't work
string image = Convert.ToBase64String(imageToByteArray(img));
public byte[] imageToByteArray(Image imageIn)
{
MemoryStream ms = new MemoryStream();
imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
return ms.ToArray();
}

If you work on a web project, you should use:
Image.FromFile(Server.MapPath("~/Images/no_image.jpg"))
else if it is a WinForm/WPF/Console application, use:
Image.FromFile(System.IO.Path.Combine(Environment.CurrentDirectory, "Images", "no_image.jpg"))

Convert Base64 String To Image Attachment

I have an image converted to a base64 string that I need to convert back to an image and attach to a MailMessage.
Here is the relevant code converting it from base64 string to image (I think I can skip the Image object and do this using one memory stream, but had some issues implementing that). Attempting to save the Image to a MemoryStream throws a generic GDI+ error:
Image image = ImageHelper.Base64ToImage(attachment.FieldData);
if (image != null)
{
using (var ms = new MemoryStream())
{
image.Save(ms, ImageFormat.Png); // Throws a generic GDI+ error on Save
ms.Position = 0;
var imageAttachment = new Attachment(ms, "image.png", "image/png");
message.Attachments.Add(imageAttachment);
}
}
public static class ImageHelper
{
public static Image Base64ToImage(string base64String)
{
if (string.IsNullOrEmpty(base64String))
{
return null;
}
byte[] imageBytes = Convert.FromBase64String(base64String);
using (var ms = new MemoryStream(imageBytes, 0, imageBytes.Length))
{
ms.Write(imageBytes, 0, imageBytes.Length);
Image image = Image.FromStream(ms, true);
return image;
}
}
}
I'm able to serve up the raw base64 string elsewhere using an img tag and it works fine so I'm confident that the problem isn't with the base64 string itself:
<img src="data:image/png;base64,<myBase64StringHere>" alt="My Image" width="500" />
I must be doing something wrong in converting it back, but I haven't been able to figure out the issue. Thanks for any help with this!

Image.FromStream(Stream) says, "You must keep the stream open for the lifetime of the Image", but your using statement disposes the stream as the Image is returned. A workaround would be to return both the image and the stream together as a tuple and without the using:
public static Tuple<Image, MemoryStream> Base64ToImage(string base64String)
{
if (string.IsNullOrEmpty(base64String))
{
return null;
}
byte[] imageBytes = Convert.FromBase64String(base64String);
var ms = new MemoryStream(imageBytes, 0, imageBytes.Length)
ms.Write(imageBytes, 0, imageBytes.Length);
Image image = Image.FromStream(ms, true);
return new Tuple<Image, MemoryStream>(image, ms);
}
Also note to take care and view each overload on the MSDN pages. Normally I would say, "view the most encompassing overload to get all the remarks and notes", but in this case that is not true. The MSDN page for the biggest overload, Image.FromStream Method (Stream, Boolean, Boolean) does not mention that you need to keep the stream open, but I am fairly certain that is a mistake on that particular page.

Convert System.Drawing.Image to System.Windows.Controls.Image?

Is there a way in C# to do this conversion and back?
I have a WPF app which has a Image control. I'm trying to save the image in that control to a SQL Database.
In my Entity Model, the datatype of the picture column in my database is a byte[]. So I found a method to convert a System.Drawing.Image to a byte[] and back. But I haven't found a method to convert from System.Windows.Controls.Image to a byte[].
So that's why I now need to do the above conversion.

If you have a byte array that represents a file that WPF can decode (bmp, jpg, gif, png, tif, ico), you can do the following:
BitmapSource LoadImage(Byte[] imageData)
{
using (MemoryStream ms = new MemoryStream(imageData))
{
var decoder = BitmapDecoder.Create(ms,
BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
return decoder.Frames[0];
}
}
Likewise, to convert it back, you can do the following:
byte[] SaveImage(BitmapSource bitmap)
{
using (MemoryStream ms = new MemoryStream())
{
var encoder = new BmpBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
encoder.Save(ms);
return ms.GetBuffer();
}
}

Well, one is an image and one is a control that shows an image, so I don't think that there's a conversion between the two. But, you could set the Source of the ...Controls.Image to be your ...Drawing.Image.
Edit based on update
Does this do what you need - http://msdn.microsoft.com/en-us/library/ms233764%28VS.100%29.aspx