Change image format using WebImage - asp.net

I'm new to asp.net and I'm making a website with asp.net mvc 4 where user can upload any type of image(png, jpeg, gif) but system will save the image as a png format. I'm using WebImage helper. So far uploading is working fine but whenever system saves the image, filename looks like this, Filename.png.jpeg. Here is my codes from Controller,
if (file != null && file.ContentLength > 0)
{
string picName = "FileName";
WebImage img = new WebImage(file.InputStream);
if (img.Width > 265 || img.Height > 158)
{
img.Resize(265, 158);
}
string picExt = Path.GetExtension(file.FileName);
if (picExt == ".jpg")
{
picExt = ".png";
}
string path = System.IO.Path.Combine(Server.MapPath("~/Images/"), picName + picExt);
img.Save(path);
}
How can I save the image as only png format no matter what user uploads in any format of image? Need this help badly. Tnx.

I had the same problem, and I just told it to ignore correct extension forcing.
The third parameter is bool forceCorrectExtension which is true by default. You don't need the second parameter since you manually set your extension.
img.Save(path, null, false);

Just ran into the same issue. Please see here:
WebImage.Save Method
Cognis is half correct and it will probably work like that. However, the 2nd parameter actually tells it what format to save as:
imageFormat Type: System.String The format to use when the image file
is saved, such as "gif", or "png".
A jpeg doesn't become a png simply because you change the extension. Unless the Save method knows to reformat based on extension (???), I would rather error on the side of caution by doing:
img.Save(path, "png", false);

Related

Save an Image with a new file name [ImageSharp]

I have upgraded my project from .net framework to .net 6 (core). In my project, there are many places where Bitmap is used. I have read in the microsoft documentations that System.Drawing.Common will only support the Windows platform and even after adding the EnableUnixSupport configuration, it will not be supported in net7.So, now I am using ImageSharp.Web. I have the scenario where I save a file as Image (the format is .tiff) then I read from that path as bitmap and save as PNG ( due to some business rule)
Following is the line of code I am trying change:
Bitmap.FromFile(completePath).Save(pngPath, ImageFormat.Png);
This is the code I have converted into. The only issue is how to save as a new file name as the Tiff file has tiff in the file name.
string extension = _GetExtension(img.ContentType);
if (extension == Constants.TiffExtension)
{
fileName = fileName.Replace(Constants.TiffExtension, "PNG");
using (var outputStream = new FileStream(completePath, FileMode.CreateNew))
{
var image = SixLabors.ImageSharp.Image.Load(completePath);
image.SaveAsync(outputStream, new PngEncoder()); //how to save new file name?
}
}
You can use the image.Save(fileName); overload to save a image to a file. The file name overload that takes just a path will automatically choose the correct encoder based on the file extension.
I was using the ImageSharp.Web package while the one I needed was the basic ImageSharp package. Special thanks to #James South for correcting me and #tocsoft for the guidance.
I have fixed it by the following code which is working:
if (extension == Constants.Conversion.TiffExtension)
{
using (SixLabors.ImageSharp.Image image = SixLabors.ImageSharp.Image.Load(completePath))
{
string pngPath = completePath.Replace(Constants.Conversion.TiffExtension, Conversion.DefaultExtension);
image.Save(pngPath);
fileName = fileName.Replace(Constants.Conversion.TiffExtension, Conversion.DefaultExtension);
}
}

how to make a picture file downloadable?

I have an ASP.NET MVC3 application and I want to link_to an image file (png, jpeg, gif, etc), and when user clicks on it, the file goes to download, instead of the browser shows it; is there any way to do this?
take your link something like this:
#Html.ActionLink(
"Download Image", // text to show
"Download", // action name
["DownloadManager", // if need, controller]
new { filename = "my-image", fileext = "jpeg" } // file-name and extension
)
and action-method is here:
public FilePathResult Download(string filename, string fileext) {
var basePath = Server.MapPath("~/Contents/Images/");
var fullPath = System.IO.Path.Combine(
basePath, string.Concat(filename.Trim(), '.', fileext.Trim()));
var contentType = GetContentType(fileext);
// The file name to use in the file-download dialog box that is displayed in the browser.
var downloadName = "one-name-for-client-file." + fileext;
return File(fullPath, contentType, downloadName);
}
private string GetContentType(string fileext) {
switch (fileext) {
case "jpg":
case "jpe":
case "jpeg": return "image/jpeg";
case "png": return "image/x-png";
case "gif": return "image/gif";
default: throw new NotSupportedException();
}
}
UPDATE:
in fact, when a file is sending to a browser, this key/value will be generated in http-header:
Content-Disposition: attachment; filename=file-client-name.ext
which file-client-name.ext is the name.extension that you want the file save-as it on client system; for example, if you want to do this in ASP.NET (none mvc), you can create a HttpHandler, write the file-stream to Response, and just add the above key/value to the http-header:
Response.Headers.Add("Content-Disposition", "attachment; filename=" + "file-client-name.ext");
just this, enjoy :D
Well technically your browser is downloading it.
I don't think you can directly link to an image, and have the browser prompt to download.
You could try something where instead of linking directly to the image, you link to a page, which serves up the image in a zip file perhaps - which of course would prompt the download to occur.
Yes, you can.
Now, you'll need to customize this to suit your needs, but I created a FileController that returned files by an identifier (you can easily return by name).
public class FileController : Controller
{
public ActionResult Download(string name)
{
// check the existence of the filename, and load it in to memory
byte[] data = SomeFunctionToReadTheFile(name);
FileContentResult result = new FileContentResult(data, "image/jpg"); // or whatever it is
return result;
}
}
Now, how you read that file or where you get it from is up to you. I then created a route like this:
routes.MapRoute(null, "files/{name}", new { controller = "File", action = "Download"});
My database has a map of identifiers to files (it's actually more complex than this, but I am omitting that logic for brevity), I can write urls like:
"~/files/somefile"
And the relevant file is downloaded.
I don't think this is possible but a simple message saying right click to save image would suffice I think.

WMF image data validation?

There is an image capturing device which gives its output in wmf. This output is stored in the database directly. We have cases where at times some of these images do not appear on a web page in IE. But if we right click on the page we are able to save the image on to the hard disk; meaning the image does exist on the page, but does not appear visible. I think this is because of some file corruption issue, but I don't know how to resolve it. We are however able to view such files using MS Picture Viewer (desktop app). Is there anyway we can detect such problematic files?
I hope I am not being over simplistic over this but the following function works for me:
public bool IsValidMetaFile(string filePath)
{
try
{
var metaFile = new Metafile(filePath);
var metaFileHeader = metaFile.GetMetafileHeader();
return metaFileHeader.IsWmf() ||
metaFileHeader.IsWmfPlaceable() ||
metaFileHeader.IsEmf() ||
metaFileHeader.IsEmfPlusDual() ||
metaFileHeader.IsEmfPlusOnly() ||
metaFileHeader.IsEmfOrEmfPlus();
}
catch (Exception mesg)
{
return false;
}
}

Out Of Memory exception on System.Drawing.Image.FromFile()

I have an image uploader and cropper which creates thumbnails and I occasionally get an Out Of Memory exception on the following line:
Dim bm As Bitmap = System.Drawing.Image.FromFile(imageFile)
The occurance of the error is tiny and very rare, but I always like to know what might be causing it. The imageFile variable is just a Server.MapPath to the path of the image.
I was curious if anyone had experience this issue previously and if they had any ideas what might be causing it? Is it the size of the image perhaps?
I can post the code if necessary and any supporting information I have, but would love to hear people's opinions on this one.
It's worth knowing that OutOfMemoryException doesn't always really mean it's out of memory - particularly not when dealing with files. I believe it can also happen if you run out of handles for some reason.
Are you disposing of all your bitmaps after you're done with them? Does this happen repeatably for a single image?
If this wasn't a bad image file but was in fact the normal issue with Image.FromFile wherein it leaves file handles open, then the solution is use Image.FromStream instead.
using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
using (Image original = Image.FromStream(fs))
{
...
Using an explicit Dispose(), a using() statement or setting the value to null on the bitmap doesn't solve the issue with Image.FromFile.
So if you App runs for a time and opens a lot of files consider using Image.FromStream() instead.
I hit the same issue today while creating Thumbnail images for a folder full of images. It turns out that the "Out Of Memory" occured exactly at the same point each time. When I looked at the folder with the images to be converted I found that the file that was creating the problem was thumbs.db. I added some code to make sure that only image files were being converted and the issue was resolved.
My code is basically
For Each imageFile as FileInfo in fileList
If imageFile.Extension = ".jpg" Or imageFile.Extension = ".gif" Then
...proceed with the conversion
End If
Next
Hope this helps.
Also check if you haven't opened the same file somewhere else. Apparently, when you open a file twice (even with File.Open()) OutOfMemoryException is thrown too...
Also you can open it in read mode, (if you want to use it in two place same time)
public Image OpenImage(string previewFile)
{
FileStream fs = new FileStream(previewFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
return Image.FromStream(fs);
}
This happens when the image file is corrupted. It is a bad error message, because memory has nothing to do with it. I haven;t worked out the coding, but a try/catch/finally will stop the program from abending.
I had a similar problem today when I was trying to resize an image and then crop it, what happened is I used this code to resize the image.
private static Image resizeImage(Image imgToResize, Size size)
{
int sourceWidth = imgToResize.Width;
int sourceHeight = imgToResize.Height;
float nPercent = 0;
float nPercentW = 0;
float nPercentH = 0;
nPercentW = ((float)size.Width / (float)sourceWidth);
nPercentH = ((float)size.Height / (float)sourceHeight);
if (nPercentH < nPercentW)
nPercent = nPercentH;
else
nPercent = nPercentW;
int destWidth = (int)(sourceWidth * nPercent);
int destHeight = (int)(sourceHeight * nPercent);
Bitmap b = new Bitmap(destWidth, destHeight);
Graphics g = Graphics.FromImage((Image)b);
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(imgToResize, 0, 0, destWidth, destHeight);
g.Dispose();
return (Image)b;
}
And then this code for the crop...
private static Image cropImage(Image img, Rectangle cropArea)
{
Bitmap bmpImage = new Bitmap(img);
Bitmap bmpCrop = bmpImage.Clone(cropArea,
bmpImage.PixelFormat);
return (Image)(bmpCrop);
}
Then this is how I called the above code...
Image img = Image.FromFile(#"C:\Users\****\Pictures\image.jpg");
img = ImageHandler.ResizeImage(img, new Size(400, 300));
img = ImageHandler.CropImage(img, new Rectangle(0, 25, 400, 250));
long quality = 90;
I kept getting errors on the crop part, the resizer worked fine!
Turns out, what was happening inside the resizer was throwing errors in the crop function. The resized calculations were making the actual dimensions of the image come out to be like 399 rather than 400 that I passed in.
So, when I passed in 400 as the argument for the crop, it was trying to crop a 399px wide image with a 400px width bmp and it threw the out of memory error!
Most of the above code was found on http://www.switchonthecode.com/tutorials/csharp-tutorial-image-editing-saving-cropping-and-resizing
If an image is an icon then different loading handling is required, like in next function:
public static Image loadImage(string imagePath)
{
Image loadedImage = null;
if (!File.Exists(imagePath)) return loadedImage;
try
{
FileInfo fileInfo = new FileInfo(imagePath);
if (fileInfo.Extension.Equals(".jpg") || fileInfo.Extension.Equals(".jpeg") ||
fileInfo.Extension.Equals(".bmp") || fileInfo.Extension.Equals(".png") ||
fileInfo.Extension.Equals(".gif"))
{
loadedImage = Image.FromFile(imagePath);
}
else if (fileInfo.Extension.Equals(".ico"))
{
Bitmap aBitmap = Bitmap.FromHicon(new
Icon(imagePath, new Size(200, 200)).Handle);
loadedImage = ImageFuncs.ResizeImage(aBitmap, new Size(30, 30));
}
}
catch (Exception eLocal)
{
MessageBox.Show(imagePath + " loading error: " + eLocal.Message);
}
return loadedImage;
}
I had the same problem with a utility I wrote to convert TIFF(s) to PDF(s). Often I would get the "out of memory" error on the same line as you.
System.Drawing.Image.FromFile(imageFile)
Then I discovered the error only happened when the file extension was ".tiff" and worked fine after I renamed it with an extension of ".tif"
I have had the same issue, before looking else where in the code wanted to make sure if I can open the Image with any Image viewer and figured out that the Image is corrupted/damaged though it's a .PNG file with 1KB size. Added a new Image in the same location, then It worked fine.
I am having same problem batch processing Tiff files. Most of the files aren't throwing an exception but few files are throwing "Out of Memory" exception in ASP.NET 4.0. I have used binary data to find out why just for few files and from within same folder. It can't be permission issue for ASP.NET ASPNET or NETWORK SERVICE account because other files are working file.
I have opened iTextSharp.text.Image class and found that there are many overloaded methods for GetInstance(). I have resolved my problem using following code: note: catch block will run for problematic files.
iTextSharp.text.Image image = null;
try
{
var imgStream = GetImageStream(path);
image = iTextSharp.text.Image.GetInstance(imgStream);
}
catch {
iTextSharp.text.pdf.RandomAccessFileOrArray ra = null;
ra = new iTextSharp.text.pdf.RandomAccessFileOrArray(path);
image = iTextSharp.text.pdf.codec.TiffImage.GetTiffImage(ra, 1);
if (ra != null)
ra.Close();
}
If you're serving from IIS, try recycling the Application Pool. This solved a similar image upload "Out of Memory" error for me.
I created a minimal form example that still gives me errors.
private void button1_Click(object sender, EventArgs e)
{
string SourceFolder = ImageFolderTextBox.Text;
string FileName = "";
DirectoryInfo Mydir = new DirectoryInfo(SourceFolder);
FileInfo[] JPEGS = Mydir.GetFiles("*.jpg");
for (int counter = 0; counter < JPEGS.Count(); counter++)
{
FileName = Mydir + "\\" + JPEGS[counter].Name;
//using (Image MyImage = System.Drawing.Image.FromFile(FileName))
using (FileStream fs = new FileStream(FileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
StatusBtn.BackColor = Color.Green;
}
}
}
I tried both the commented out line using Image.FromFile() as well as the line using FileStream(). Both produced file errors.
The Image.FromFile() error was:
System.OutOfMemoryException: 'Out of Memory'
The filestream() error was:
System.UnaurthorizedAccessException: 'Access to the path 'E:\DCIM\100Canon\dsc_7218.jpg' is denied.
I placed a Breakpoint just prior to the lines producing the error and I am able to open the image file using the Windows image viewer. I then closed the viewer and after I advanced to the next line and get the error, I can no longer view the image with the Windows viewer. Instead, I get a message that I do not have permission to access the file. I am able to delete the file.
This error is repeatable. I've done it over 10 times. Each time, after I get the error, I delete the file used for FileName.
All files were verified to be non-corrupt.
My original code that used Image.FromFile() worked fine when I compiled it 2 years ago. In fact, the .exe file runs just fine. I made a minor change somewhere else in the code and was surprised to find that the code would not compile without this error. I tried the FileStream() method based on the information on this page.

Add filter to FileUpload Control

How to add filter to the fileupload control in asp.net? I want a filter for Word Template File (.dot).
You could also do a javascript alternative to filtering it server side (you'd probably want to do that as well) but this saves the client from spending the time waiting on an upload to finish just to find out it was the wrong type.
http://javascript.internet.com/forms/upload-filter.html
So basically you just run a javascript function on submit that parses off the extension of the uploaded file and gives them an alert if its not of the right type.
You could also use document.forms[0].submit(); instead of passing the form reference through (as ASP.NET really only uses a single form (unless your doing something funky))
string fileName = fuFiles.FileName;
if(fileName.Contains(".dot"))
{
fuFiles.SaveAs(Server.MapPath("~/Files/" + fileName));
}
If you mean to filter the file extensions client/side, with the standard browser's file selector, isn't possible.
To do that you have to use a mixed type of upload, such as SWFUpload, based on a flash uploader system (that's a really nice techinque: it allows you to post more than a file at time).
The only thing you can do in standard mode is to filter the already posted file, and I suggest to use System.IO.Path namespace utility:
if (Path.GetExtension(upFile.FileName).ToUpper().CompareTo(".DOT") == 0)
{
/* do what you want with file here */
}
Check the filename of the uploaded file serverside:
FileUpload1.PostedFile.FileName
Unless you want to use java or something similar on the client, there's really not much you can do for filtering uploaded files before they're sent to the server.
Here I have a small method that I used to filter which types of files can be uploaded by the fileupload control named fuLogo.
if (fuLogo.HasFile)
{
int counter = 0;
string[] fileBreak = fuLogo.FileName.Split(new char[] { '.' });
logo = Server.MapPath("../Images/Logos/" + fileBreak[0] + counter.ToString()+ "." + fileBreak[1]);
if (fileBreak[1].ToUpper() == "GIF" || fileBreak[1].ToUpper() == "PNG")
{
while (System.IO.File.Exists(logo))
{
counter++;
logo = Server.MapPath("../Images/Logos/" + fileBreak[0] + counter.ToString() + "." + fileBreak[1]);
}
}
else
{
cvValidation.ErrorMessage = "This site does not support any other image format than .Png or .Gif . Please save your image in one of these file formats then try again.";
cvValidation.IsValid = false;
}
fuLogo.SaveAs(logo);
}
basically, I first Iterates through the directory to see if a file already exists. Should the file exist, (example picture0.gif) , it will increase the counter (to picture1.gif). It prevents that different users will overwrite each other's pictures should their pictures have the same name.

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