I have a web app that runs on Azure. The user can upload an image and I save that image for them. Now when I receive the image, I have it as byte[]. I would like to save it as JPG to save space. The source image could be anything such as PNG, BMP or JPG.
Is it possible to do so? This needs to run on Azure and I am using WebApps/MVC5/C#.
Thanks for any help.
Get the memorystream and then use System.Drawing
var stream = new MemoryStream(byteArray)
Image img = new Bitmap(stream);
img.Save(#"c:\s\pic.png", System.Drawing.Imaging.ImageFormat.Png);
The last line there where you save the file, you can select the format.
So the answers by #mjwills and Cody was correct. I still thought to put the two methods I exactly needed:
public static Image BitmapToBytes(byte[] image, ImageFormat pFormat)
{
var imageObject = new Bitmap(new MemoryStream(image));
var stream = new MemoryStream();
imageObject.Save(stream, pFormat);
return new Bitmap(stream);
}
Also:
public static byte[] ImgToByteArray(Image img)
{
using (MemoryStream mStream = new MemoryStream())
{
img.Save(mStream, img.RawFormat);
return mStream.ToArray();
}
}
Cheers everyone.
i've got some binary data which i want to save as an image. When i try to save the image, it throws an exception if the memory stream used to create the image, was closed before the save. The reason i do this is because i'm dynamically creating images and as such .. i need to use a memory stream.
this is the code:
[TestMethod]
public void TestMethod1()
{
// Grab the binary data.
byte[] data = File.ReadAllBytes("Chick.jpg");
// Read in the data but do not close, before using the stream.
Stream originalBinaryDataStream = new MemoryStream(data);
Bitmap image = new Bitmap(originalBinaryDataStream);
image.Save(#"c:\test.jpg");
originalBinaryDataStream.Dispose();
// Now lets use a nice dispose, etc...
Bitmap2 image2;
using (Stream originalBinaryDataStream2 = new MemoryStream(data))
{
image2 = new Bitmap(originalBinaryDataStream2);
}
image2.Save(#"C:\temp\pewpew.jpg"); // This throws the GDI+ exception.
}
Does anyone have any suggestions to how i could save an image with the stream closed? I cannot rely on the developers to remember to close the stream after the image is saved. In fact, the developer would have NO IDEA that the image was generated using a memory stream (because it happens in some other code, elsewhere).
I'm really confused :(
As it's a MemoryStream, you really don't need to close the stream - nothing bad will happen if you don't, although obviously it's good practice to dispose anything that's disposable anyway. (See this question for more on this.)
However, you should be disposing the Bitmap - and that will close the stream for you. Basically once you give the Bitmap constructor a stream, it "owns" the stream and you shouldn't close it. As the docs for that constructor say:
You must keep the stream open for the
lifetime of the Bitmap.
I can't find any docs promising to close the stream when you dispose the bitmap, but you should be able to verify that fairly easily.
A generic error occurred in GDI+.
May also result from incorrect save path!
Took me half a day to notice that.
So make sure that you have double checked the path to save the image as well.
Perhaps it is worth mentioning that if the C:\Temp directory does not exist, it will also throw this exception even if your stream is still existent.
Copy the Bitmap. You have to keep the stream open for the lifetime of the bitmap.
When drawing an image: System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI
public static Image ToImage(this byte[] bytes)
{
using (var stream = new MemoryStream(bytes))
using (var image = Image.FromStream(stream, false, true))
{
return new Bitmap(image);
}
}
[Test]
public void ShouldCreateImageThatCanBeSavedWithoutOpenStream()
{
var imageBytes = File.ReadAllBytes("bitmap.bmp");
var image = imageBytes.ToImage();
image.Save("output.bmp");
}
I had the same problem but actually the cause was that the application didn't have permission to save files on C. When I changed to "D:\.." the picture has been saved.
You can try to create another copy of bitmap:
using (var memoryStream = new MemoryStream())
{
// write to memory stream here
memoryStream.Position = 0;
using (var bitmap = new Bitmap(memoryStream))
{
var bitmap2 = new Bitmap(bitmap);
return bitmap2;
}
}
This error occurred to me when I was trying from Citrix. The image folder was set to C:\ in the server, for which I do not have privilege. Once the image folder was moved to a shared drive, the error was gone.
A generic error occurred in GDI+. It can occur because of image storing paths issues,I got this error because my storing path is too long, I fixed this by first storing the image in a shortest path and move it to the correct location with long path handling techniques.
I was getting this error, because the automated test I was executing, was trying to store snapshots into a folder that didn't exist. After I created the folder, the error resolved
One strange solution which made my code to work.
Open the image in paint and save it as a new file with same format(.jpg). Now try with this new file and it works. It clearly explains you that the file might be corrupted in someway.
This can help only if your code has every other bugs fixed
It has also appeared with me when I was trying to save an image into path
C:\Program Files (x86)\some_directory
and the .exe wasn't executed to run as administrator, I hope this may help someone who has same issue too.
For me the code below crashed with A generic error occurred in GDI+on the line which Saves to a MemoryStream. The code was running on a web server and I resolved it by stopping and starting the Application Pool that was running the site.
Must have been some internal error in GDI+
private static string GetThumbnailImageAsBase64String(string path)
{
if (path == null || !File.Exists(path))
{
var log = ContainerResolver.Container.GetInstance<ILog>();
log.Info($"No file was found at path: {path}");
return null;
}
var width = LibraryItemFileSettings.Instance.ThumbnailImageWidth;
using (var image = Image.FromFile(path))
{
using (var thumbnail = image.GetThumbnailImage(width, width * image.Height / image.Width, null, IntPtr.Zero))
{
using (var memoryStream = new MemoryStream())
{
thumbnail.Save(memoryStream, ImageFormat.Png); // <= crash here
var bytes = new byte[memoryStream.Length];
memoryStream.Position = 0;
memoryStream.Read(bytes, 0, bytes.Length);
return Convert.ToBase64String(bytes, 0, bytes.Length);
}
}
}
}
I came across this error when I was trying a simple image editing in a WPF app.
Setting an Image element's Source to the bitmap prevents file saving.
Even setting Source=null doesn't seem to release the file.
Now I just never use the image as the Source of Image element, so I can overwrite after editing!
EDIT
After hearing about the CacheOption property(Thanks to #Nyerguds) I found the solution:
So instead of using the Bitmap constructor I must set the Uri after setting CacheOption BitmapCacheOption.OnLoad.(Image1 below is the Wpf Image element)
Instead of
Image1.Source = new BitmapImage(new Uri(filepath));
Use:
var image = new BitmapImage();
image.BeginInit();
image.CreateOptions = BitmapCreateOptions.IgnoreImageCache;
image.CacheOption = BitmapCacheOption.OnLoad;
image.UriSource = new Uri(filepath);
image.EndInit();
Image1.Source = image;
See this: WPF Image Caching
Try this code:
static void Main(string[] args)
{
byte[] data = null;
string fullPath = #"c:\testimage.jpg";
using (MemoryStream ms = new MemoryStream())
using (Bitmap tmp = (Bitmap)Bitmap.FromFile(fullPath))
using (Bitmap bm = new Bitmap(tmp))
{
bm.SetResolution(96, 96);
using (EncoderParameters eps = new EncoderParameters(1))
{
eps.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 100L);
bm.Save(ms, GetEncoderInfo("image/jpeg"), eps);
}
data = ms.ToArray();
}
File.WriteAllBytes(fullPath, data);
}
private static ImageCodecInfo GetEncoderInfo(string mimeType)
{
ImageCodecInfo[] encoders = ImageCodecInfo.GetImageEncoders();
for (int j = 0; j < encoders.Length; ++j)
{
if (String.Equals(encoders[j].MimeType, mimeType, StringComparison.InvariantCultureIgnoreCase))
return encoders[j];
}
return null;
}
I used imageprocessor to resize images and one day I got "A generic error occurred in GDI+" exception.
After looked up a while I tried to recycle the application pool and bingo it works. So I note it here, hope it help ;)
Cheers
I was getting this error today on a server when the same code worked fine locally and on our DEV server but not on PRODUCTION. Rebooting the server resolved it.
public static byte[] SetImageToByte(Image img)
{
ImageConverter converter = new ImageConverter();
return (byte[])converter.ConvertTo(img, typeof(byte[]));
}
public static Bitmap SetByteToImage(byte[] blob)
{
MemoryStream mStream = new MemoryStream();
byte[] pData = blob;
mStream.Write(pData, 0, Convert.ToInt32(pData.Length));
Bitmap bm = new Bitmap(mStream, false);
mStream.Dispose();
return bm;
}
I have an byte array of image in my local computer, using windows service i want to
convert it as a image and save it in a server folder I know the Ip address of the server
As of now I have tried something like this
byte[] photo = publicData.Photography;
MemoryStream ms = new MemoryStream(photo, 0, photo.Length);
ms.Position = 0;
ms.Write(photo, 0, photo.Length);
System.Drawing.Image image = System.Drawing.Image.FromStream(ms, true);// this line giving exception parameter not valid
image.Save(172.16.16.32/E/xyz);
If you already have the bytes, why bother with the streams and image obejcts?
byte[] photo = publicData.Photography;
var path = #"\\172.16.16.32\E\xyz\file.jpg";
File.WriteAllBytes(path, photo);
Please try this
var path = #"\172.16.16.32\E$\xyz\file.jpg";
Is there a way to convert a BitmapImage (Windows.UI.Xaml.Media.BitmapImage) to an Byte[] Array? Nothing I've tried work....
Another possible scenario (if BitmapImage cannot be converted to Byte array) is to download the image from web and then convert it to an array...
But I don't know how I can do that...
It would be really nice, if someone have an idea.
Current try:
HttpClient http = new HttpClient();
Stream resp = await http.GetStreamAsync("http://localhost/img/test.jpg");
var ras = new InMemoryRandomAccessStream();
await resp.CopyToAsync(ras.AsStreamForWrite());
BitmapImage bi = new BitmapImage();
bi.SetSource(ras);
byte[] pixeBuffer = null;
using (MemoryStream ms = new MemoryStream())
{
int i = bi.PixelHeight;
int i2 = bi.PixelWidth;
WriteableBitmap wb = new WriteableBitmap(bi.PixelWidth, bi.PixelHeight);
Stream s1 = wb.PixelBuffer.AsStream();
s1.CopyTo(ms);
pixeBuffer = ms.ToArray();
}
But it doesn't work... i & i2 are always set to 0. So ras doesn't work correctly.... What's going on?
Thanks
In your code you're never waiting for the BitmapImage to load the image from the web, so it does not know its PixelWidth/PixelHeight when you access them. You could wait for it to load - for example using the AsyncUI library by calling "await bi.WaitForLoadedAsync()". This would not really help you here if you want to access the decoded pixels since BitmapImage does not give you access to the pixels and there is currently no API to convert a BitmapImage into a WriteableBitmap.
You can check an earlier question about the topic. You would need to get the image file from the web with something like HttpClient.GetAsync(), then load it using something like BitmapDecoder.
If I can retrieve image data from sql-server database, which stored as image type. How can I display the image in my web application using c#? Thanks in advance.
You have to create an http handler that returns the image
public void ProcessRequest(HttpContext context)
{
Byte[] yourImage = //get your image byte array
context.Response.BinaryWrite(yourImage);
context.Request.ContentType = "image/jpeg";
context.Response.AddHeader("Content-Type", "image/jpeg");
context.Response.AddHeader("Content-Length", (yourImage).LongLength.ToString());
con.Close();
context.Response.End();
context.Response.Close();
}
You can can do that by creating a GenericHandler file type from the visual studio and add the previous code in then you can call you can write the url of the generic handler as the image source
MemoryStream ms = new MemoryStream(byteArrayFromDB);
Image returnImage = Image.FromStream(ms);
You may want to look at this as well
byte[] imageBytes = (byte[]) imageReader.GetValue(0);
MemoryStream ms = new MemoryStream(imageBytes);
FileStream fs = File.OpenWrite(imagePath);
fs.Write(ms.GetBuffer(), 0, ms.Position());