Develop Reference

ExternalException when saving .bmp to MemoryStream as .png

I'm converting a batch of .bmp's to .png. This is the relevant part of the code:
foreach (string path in files) {
using (fs = new FileStream(path, FileMode.Open)) bmp = new Bitmap(fs);
using (ms = new MemoryStream()) {
bmp.Save(ms, ImageFormat.Png);
bmp.Dispose();
png = Image.FromStream(ms);
}
png.Save(path);
}
At the line bmp.Save(ms, ImageFormat.Png); the following exception is thrown:
System.Runtime.InteropServices.ExternalException: 'A generic error occurred in GDI+.'
According to MSDN this means the image was either saved with the wrong format or to the same location it was read from. The latter is not the case. However, I don't see how I gave it the wrong format: on the same MSDN page an example is given where a .bmp is converted to a .gif in the same manner.
Does it have to do with me saving to a MemoryStream? This is done so that I can overwrite the original file with the converted one. (Note that the .bmp suffix is kept intentionally. This shouldn't be the problem, since the exception appears before the final file is saved.)

In the MSDN documentation of that Bitmap constructor it says:
You must keep the stream open for the lifetime of the Bitmap.
and that same remark can be found on Image.FromStream.
So your code should carefully handle the scope and lifetime of the streams it uses for each of those bitmaps/images.
Combining all that the following code handles those streams correctly:
foreach (string path in files) {
using (var ms = new MemoryStream()) //keep stream around
{
using (var fs = new FileStream(path, FileMode.Open)) // keep file around
{
// create and save bitmap to memorystream
using(var bmp = new Bitmap(fs))
{
bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
}
}
// write the PNG back to the same file from the memorystream
using(var png = Image.FromStream(ms))
{
png.Save(path);
}
}
}

Save Image from Memorystream using C# and ASP.NET

I am using a memory stream to resize an image through a FileUpload control. After it resizes it I want it to save to my filesystem at "~/images/2012/" + filename.
How do I save the image from a memorystream?
System.Drawing.Image imageLarge = System.Drawing.Image.FromStream(stream);
System.Drawing.Image imageLarge1 = ResizeImage(imageLarge, 200, 300);
MemoryStream memolarge = new MemoryStream();
imageLarge1.Save(memolarge, System.Drawing.Imaging.ImageFormat.Jpeg);
System.Drawing.Image returnImage = System.Drawing.Image.FromStream(memolarge);
Encoder myEncoder;
EncoderParameter myEncoderParameter;
EncoderParameters myEncoderParameters;
myEncoder = Encoder.Quality;
myEncoderParameter = new EncoderParameter(myEncoder, 100L);
myEncoderParameters.Param[0] = myEncoderParameter;
string convertedImage = returnImage.ToString();
returnImage.Save("~/images/2012/" + filename,
ImageFormat.Jpeg, myEncoderParameters);
This is the error I am getting along with an overloaded method error:
cannot convert from 'System.Drawing.Imaging.ImageFormat' to System.Drawing.Imaging.ImageCodecInfo

Look at the overloads of Image.Save.
Only the final two accept EncoderParameters, and neither of them accept an ImageFormat - both accept an ImageCodecInfo.
It's very important to be able to diagnose this kind of problem yourself:
Look at the compiler error carefully
Read the documentation
Check whether the call you're making makes sense
This has nothing to do with saving to a MemoryStream in particular - in fact, it's not clear why you're saving an Image and then immediately loading an Image from the same stream. (I'd advise setting the Position to 0 before you do so anyway, if you really want to keep doing this.)

Try this line instead:
returnImage.Save(
"~/images/2012/" + filename,
ImageCodecInfo.GetImageEncoders()
.Where(i => i.MimeType == "image/jpeg")
.First(),
myEncoderParameters);

See post Saving as jpeg from memorystream in c# it does something very similar to what you are looking for.
Also to change the codec properly
http://msdn.microsoft.com/en-us/library/ytz20d80.aspx

Open Image from file, then release lock?

I'm using the following line of code to open an Image from a file:
pictureBox1.Image = Image.FromFile("test.png");
I expect it to lock the file, load the image to memory, set pictureBox1.Image to the copy in memory, and release the lock. In reality, the lock won't go away until I Dispose() of the Image in memory. I can not release the lock on the file on the harddrive that I am no longer using until I get rid of the file in memory that I am using.
Microsoft's site mentions it in a C#-labeled article, but their solution is written in visual basic, which is useless to me.
In summary:
I want to set pictureBox1.Image to the image stored in "test.png", then let the user edit or delete "test.png" or whatever.

The approach with stream is not correct.
See here https://stackoverflow.com/a/8701748/355264
Correct code from above link:
Image img;
using (var bmpTemp = new Bitmap("image_file_path"))
{
img = new Bitmap(bmpTemp);
}

Or better yet, use a using statement (the code below is otherwise copied from sylon's [deleted] post). This way if the Image.FromStream throws an exception, you can still be assured that the stream is immediately closed.
using (FileStream stream = new FileStream("test.png", FileMode.Open, FileAccess.Read))
{
pictureBox1.Image = Image.FromStream(stream);
}

You can also use a stream to read the image then close the stream.
FileStream stream = new FileStream("test.png", FileMode.Open, FileAccess.Read);
pictureBox1.Image = Image.FromStream(stream);
stream.Close();

The easiest ever way I found is to freeze the object that contains the Source (path to the file). All controls that can contain an image, seem to have a .Source which, if not null, it will lock the file it points to.
Now the trick is to change the Image control to a "read-only" state, which then unlocks the file.
My solution:
private Image CreatePreviewImage()
{
Image ReportImage = new Image();
Uri path = new Uri(#"C:\Folder\Image1.png");
if (File.Exists(path.OriginalString))
{
ReportImage.Name = "Report1";
ReportImage.Source = LoadImageFromFile(path);
}
return ReportImage;
}
public ImageSource LoadImageFromFile(Uri path)
{
BitmapImage bitmap = new BitmapImage();
bitmap.BeginInit();
bitmap.UriSource = path;
bitmap.CacheOption = BitmapCacheOption.OnLoad;
bitmap.CreateOptions = BitmapCreateOptions.IgnoreImageCache;
bitmap.DecodePixelWidth = 900;
bitmap.EndInit();
bitmap.Freeze(); //This is the magic line that releases/unlocks the file.
return bitmap;
}

talking open, read and release
StreamReader streamReader = new StreamReader("picture.png");
Bitmap tmpBitmap = (Bitmap)Bitmap.FromStream(streamReader.BaseStream);
streamReader.Close();
pictureBox1.Image = tmpBitmap;`

A generic error occured in GDI+

I'm attempting to resize and image using the following function and receiving this error:
Exception Details: System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+.
on this line:
imageConvertedToBitmap.Save(cachedFileName, info[1], encoderParameters);
Any ideas why this might be happening?
private byte[] GetCachedImage(string cachedFileName, string pathToImage, int width, int height)
{
if (!System.IO.File.Exists(cachedFileName) || (System.IO.File.GetLastWriteTime(pathToImage) > System.IO.File.GetLastWriteTime(cachedFileName)))
{
Image imageToResize = Image.FromFile(pathToImage);
Image imageConvertedToBitmap = new Bitmap(width, height);
Graphics graphicsController = Graphics.FromImage(imageConvertedToBitmap);
graphicsController.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphicsController.SmoothingMode = SmoothingMode.HighQuality;
graphicsController.PixelOffsetMode = PixelOffsetMode.HighQuality;
graphicsController.CompositingQuality = CompositingQuality.HighQuality;
graphicsController.DrawImage(imageToResize, 0, 0, width, height);
EncoderParameters parameters = new EncoderParameters(1);
parameters.Param[0] = new EncoderParameter(Encoder.Quality, 80L);
ImageCodecInfo[] info = ImageCodecInfo.GetImageEncoders();
EncoderParameters encoderParameters = new EncoderParameters(1);
encoderParameters.Param[0] = new EncoderParameter(Encoder.Quality, 80L);
MemoryStream memoryStream = new MemoryStream();
imageConvertedToBitmap.Save(cachedFileName, info[1], encoderParameters);
imageConvertedToBitmap.Save(memoryStream, info[1], encoderParameters);
imageToResize.Dispose();
imageConvertedToBitmap.Dispose();
graphicsController.Dispose();
parameters.Dispose();
encoderParameters.Dispose();
return memoryStream.GetBuffer();
}
byte[] buffer = null;
try
{
FileStream fileStream = new FileStream(cachedFileName, FileMode.Open, FileAccess.Read);
BinaryReader binaryReader = new BinaryReader(fileStream);
long totalBytes = new FileInfo(cachedFileName).Length;
buffer = binaryReader.ReadBytes((Int32)totalBytes);
fileStream.Close();
fileStream.Dispose();
binaryReader.Close();
}
catch { }
return buffer;
}

It was a permissions error. Had to give appropriate Write permission to the directory I was saving to. Sometimes it's the simple things. :)
From what I read, when getting this GDI+ error, the first thing to check should be permissions as it's almost always an indicator of a security problem.

Try an overload of Save that doesn't take EncoderParameters as a parameter. It should work fine and produce the resized image that you're looking for.

I had this error one time, it was because I tried to save under a locked file by a Bitmap object.
We just see your method but not how you use it.
I think there are several syntax problems in your code : you must use "using() { }" for all the disable objects in your code.
using(Image imageToResize = Image.FromFile(pathToImage))
using(Image imageConvertedToBitmap = new Bitmap(width, height))
etc.
{
}

Your got this error on another instance.
Firstly understand what this error means the other way:
When you get the error, go to task manager and navigate to Details tab.
Right click on the table headers and click select columns.
Tick the GDI objects checkbox.
Now find the name of your program in the table and check the no. of GDI objects.
It would have exceeded 10000 or must be at 10000.
The error pops up whenever the no. of GDI objects by a program exceeds
10000 as 10000 is the limit.
Check how many times the System.Drawing.... runs in your code.
Prevent objects like Fonts or Images from being created again and again.
Instead set a reference point.

Image.Save(..) throws a GDI+ exception because the memory stream is closed

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;
}