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);
}
}
}
I am trying to compress files with GZIP and my application monitors a folder for new files. When a new file comes in, it should be compressed and then application should continue doing this every time a new file comes in folder.
private void Compress(string filePath)
{
using (FileStream inputStream = new FileStream(filePath,FileMode.OpenOrCreate,FileAccess.ReadWrite))
{
using (FileStream outputStream = new FileStream(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), #"C:\\Users\\maki\\Desktop\\Input"), FileMode.OpenOrCreate, FileAccess.ReadWrite))//'System.UnauthorizedAccessException'
{
using (GZipStream gzip = new GZipStream(outputStream, CompressionMode.Compress))
{
inputStream.CopyTo(gzip);
}
}
}
}
when I execute the application, I get this exception:
An unhandled exception of type 'System.UnauthorizedAccessException' occurred in mscorlib.dll
Additional information:
Access to the path 'C:\Users\maki\Desktop\Input' is denied.
I've searched a lot in internet but couldn't find a proper answer.
Can anyone help me with issue?
The issue could be related you to the way the file stream is instantiated. In your code, you are combining a path, with the Path.Combine method with another fully qualified path.
Please see the code below. Another issue could be related to the hard coded path. Is the file named Input or Input.gz? Also note the ability to stack using statements for reduced nesting.
private void Compress(string filePath)
{
using (FileStream inputStream =
new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
using (FileStream outputStream =
new FileStream(#"C:\\Users\\maki\\Desktop\\Input",
FileMode.OpenOrCreate, FileAccess.ReadWrite))
using (GZipStream gzip = new GZipStream(outputStream, CompressionMode.Compress))
{
inputStream.CopyTo(gzip);
}
}
I'm developing a Winforms application. This code contains it to save an image to a SQL Server table. But sometimes a Out of memory exception happens when I'm returning the binary data from the table to display the image.
This is my code to convert image before save.
openImage.Filter = "Image Files(*.jpg; *.jpeg; *.gif; *.bmp)|*.jpg; *.jpeg; *.gif; *.bmp";
if (openImage.ShowDialog() == DialogResult.OK)
{
pictureBox1.Image = new Bitmap(openImage.FileName);
pictureBox1.SizeMode = PictureBoxSizeMode.CenterImage;
lblImgInfo.Text = openImage.FileName;
FRM_ImageViewer imgver = new FRM_ImageViewer(openImage.FileName);
imgver.Show();
string strFn = openImage.FileName;
FileInfo fiImage = new FileInfo(strFn);
long m_lImageFileLength =fiImage.Length;
byte[] m_barrImg = new byte[Convert.ToInt32(m_lImageFileLength)];
FileStream fs = new FileStream(strFn, FileMode.Open, FileAccess.Read, FileShare.Read);
int iBytesRead = fs.Read(m_barrImg, 0,Convert.ToInt32(m_lImageFileLength));
fs.Close();
}
and this is my code to retrieve the image from the database
// DTSelectedJobs is a DataTable in csharp.
byte[] barrImg = (byte[])DTSelectedJobs.Rows[0].ItemArray[11];
string strfn = Convert.ToString(DateTime.Now.ToFileTime());
FileStream fs2 = new FileStream(strfn, FileMode.CreateNew, FileAccess.Write);
fs2.Write(barrImg, 0, barrImg.Length);
fs2.Flush();
fs2.Close();
FRM_ImageViewer imgvwr = new FRM_ImageViewer(strfn);
imgvwr.Show();
Can someone please give me an advice how to find the error?
Bitmap inherits from Image which is Disposable, you need to dispose of your bitmap.
using(var bmp = new Bitmap(openImage.FileName))
{
pictureBox1.Image = bmp;
}
As DGibbs notes, you need to do the same for FileStream
using(var fs = new FileStream(strFn, FileMode.Open, FileAccess.Read,
FileShare.Read))
int iBytesRead = fs.Read(m_barrImg, 0,Convert.ToInt32(m_lImageFileLength));
I'm not all that familiar with winforms so bear with me but this looks incorrect to me.
You create a strfn:
string strfn = Convert.ToString(DateTime.Now.ToFileTime());
And then initialize an image viewer with... a date/time string?
FRM_ImageViewer imgvwr = new FRM_ImageViewer(strfn);
Seems like barrImg is what should be in the ctor here?
Also, FileStream implements the IDisposable interface so should be ideally wrapped in a using block:
using(FileStream fs2 = new FileStream(strfn, FileMode.CreateNew, FileAccess.Write))
{
fs2.Write(barrImg, 0, barrImg.Length);
FRM_ImageViewer imgvwr = new FRM_ImageViewer(strfn);
imgvwr.Show();
}
It's almost an year since the question was asked but let me share my thoughts since there is not an answer yet
Out of memory exception was thrown because there is not enough memory
available for your application or your application is using too much
memory than available.
I would check the following to find why the application is using too much memory
1) Make sure table returns only required data. Because size of an image is large. If your database returns a large result then, the result set may use several MB's of memory.
Assuming you are trying to view an image saved in data base, if you are displaying n images then query for the specific records.
2) Make sure you are disposing all the disposable objects like Image, Bitmap,Stream, FileStream, Pen, etc., because it may cause memory leak in your application
3) Use a memory profiler to check for memory leaks in the application.
Here is what I am trying to do: Thread B will download some images and store those images in a shared resource: Static ArrayList IMBuffer; thread A will take an image from IMBuffer and do something with it. The following is what I got:
Thread B:
// do something
System.Net.WebClient myWebClient = new System.Net.WebClient();
try
{ myWebClient.DownloadFile(pth, "BufferImg"); }
catch
{ // some stuff }
// add new dled image to IMBuffer
fs = new FileStream("BufferImg", FileMode.Open, FileAccess.Read);
Image img = Image.FromStream(fs);
lock (IMBuffer)
{ IMBuffer.Add(img); }
img.Dispose();
lock (IMRequest) { IMRequest.RemoveAt(0); }
myWebClient.Dispose();
//fs.Dispose();
// File.Delete("BufferImg");
// do something else
Thread A:
// do something
Image nextImg;
lock (IMBuffer)
{
nextImg = (Image)IMBuffer[0];
nextImg.Save(DLedIM);
}
// do something else
and here is the problem I am running to; since the images in IMBuffer was opened using a filestream, when the stream is disposed, the line: nextImg.Save(DLedIM); is causing "file is been used by another process" error. However if fs.Dispose(); line is commented out, then the program is locking up "BufferImg", as the result, it won't be able to download image to "BufferImg" after the first time. What should I do to fix this problem? Or is there a simpler way to accomplish what I am trying to do?
This should work:
byte[] buffer;
using (FileStream fs = new FileStream("BufferImg", FileMode.Open, FileAccess.Read))
{
buffer = new byte[fs.Length];
fs.Read(buffer, 0, (int)fs.Length);
}
using(Image img = Image.FromStream(new MemoryStream(buffer))
{
//...
}
Using a MemoryStream you avoid having to hold on to the FileStream - at this point the image does not have any connection at all to the file and hence you shouldn't have any problem with file locking.
Instead of implementing your own multithread producer/consumer workflow (and then having to debug it), why not just use an existing threadsafe (nay, concurrent) queue provided by .NET? Could save you a lot of trial and even more errors.
Details here: Thread-safe blocking queue implementation on .NET
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;
}