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Resizing and saving an image in c# that's downloaded from a remote URL

I have some code which downloads a file from a remote URL and saves it quite efficiently.
How can I modify this to set the height to be 120px (and width scale accordingly) when I save it?
private static bool DownloadRemoteImageFile(string uri, string fileName)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
HttpWebResponse response;
try
{
response = (HttpWebResponse)request.GetResponse();
}
catch (Exception)
{
return false;
}
if ((response.StatusCode == HttpStatusCode.OK ||
response.StatusCode == HttpStatusCode.Moved ||
response.StatusCode == HttpStatusCode.Redirect) &&
response.ContentType.StartsWith("image", StringComparison.OrdinalIgnoreCase))
{
using (Stream inputStream = response.GetResponseStream())
using (Stream outputStream = System.IO.File.OpenWrite(fileName))
{
var buffer = new byte[4096];
int bytesRead;
do
{
bytesRead = inputStream.Read(buffer, 0, buffer.Length);
outputStream.Write(buffer, 0, bytesRead);
} while (bytesRead != 0);
}
return true;
}
return false;
}
The examples I've seen use the Bitmap class which I'm not using, do I need to change how I download my file?

Update your DownloadRemoteImageFile method to return a byte[]:
private static byte[] DownloadRemoteImageFile(string uri)
{
byte[] content;
var request = (HttpWebRequest)WebRequest.Create(uri);
using (var response = request.GetResponse())
using (var reader = new BinaryReader(response.GetResponseStream()))
{
content = reader.ReadBytes(100000);
}
return content;
}
Then use System.Drawing classes to re-size and save the image:
static void Main(string[] args)
{
var img = DownloadRemoteImageFile( // Put your url here );
Image original;
using (var ms = new MemoryStream(img))
{
original = Image.FromStream(ms);
}
var newHeight = 120;
var newWidth = ScaleWidth(original.Height, 120, original.Width);
using (var newPic = new Bitmap(newWidth, newHeight))
using (var gr = Graphics.FromImage(newPic))
{
gr.DrawImage(original, 0, 0, newWidth, newHeight);
newPic.Save(#"C:\newImage1.jpg", ImageFormat.Jpeg);
}
}
To scale the width:
private static int ScaleWidth(int originalHeight, int newHeight, int originalWidth)
{
var scale = Convert.ToDouble(newHeight) / Convert.ToDouble(originalHeight);
return Convert.ToInt32(originalWidth * scale);
}

How to download an image URL to switch to byte [] up and read it WP8 C#

for (int i = 3; i < 10; i++)
{
Uri uriimg = new Uri("http://i.msdn.microsoft.com/dynimg/IC53593" + i + ".jpg", UriKind.RelativeOrAbsolute);
SaveToLocalStorage(ImageToArray(uriimg), "anh1.jpg");
}
private byte[] ImagesToArray(Uri uriimg)
{
var image = new BitmapImage(uriimg);
MemoryStream ms = new MemoryStream();
image.ImageOpened += (s, e) =>
{
image.CreateOptions = BitmapCreateOptions.None;
WriteableBitmap wb = new WriteableBitmap(image);
wb.SaveJpeg(ms, image.PixelWidth, image.PixelHeight, 0, 100);
};
return ms.ToArray();
}
public async void SaveToLocalStorage(byte[] _imageBytes, string fileName)
{
if (_imageBytes == null)
{
return;
}
var isoFile = IsolatedStorageFile.GetUserStoreForApplication();
if (!isoFile.DirectoryExists("dataImages"))
{
isoFile.CreateDirectory("dataImages");
}
string filePath = System.IO.Path.Combine("dataImages", fileName);
using (var stream = isoFile.CreateFile(filePath))
{
await stream.WriteAsync(_imageBytes, 0, _imageBytes.Length);
}
}
public ImageSource LoadFromLocalStorage(string fileName)
{
var isoFile = IsolatedStorageFile.GetUserStoreForApplication();
ImageSource imageSource = null;
if (isoFile.DirectoryExists("dataImages"))
{
string filePath = System.IO.Path.Combine("dataImages", fileName);
using (var imageStream = isoFile.OpenFile(filePath, FileMode.Open, FileAccess.Read))
{
imageSource = PictureDecoder.DecodeJpeg(imageStream);
}
}
return imageSource;
}
I get the value as byte [0] it can not convert to byte [].

The problem I see is in ImagesToArray. You create a new MemoryStream, subscribe to an event that sets it, and then immediately return it. I'm pretty sure that ms will have 0 bytes when it is returned.
You should instead not use image.ImageOpened, and just put that code in the ImagesToArray method directly:
private byte[] ImagesToArray(Uri uriimg)
{
var image = new BitmapImage(uriimg);
MemoryStream ms = new MemoryStream();
image.CreateOptions = BitmapCreateOptions.None;
WriteableBitmap wb = new WriteableBitmap(image);
wb.SaveJpeg(ms, image.PixelWidth, image.PixelHeight, 0, 100);
return ms.ToArray();
}

Upload png Image with ftp loose transparency

In my c# application, I'm trying to upload an png image using ftp, the problem is I loose transparency (the transparent area turn to black!).
PS : The image I send is stored in an Sql Server database, and they look fine in my application. Here is the code I use :
private const int defultbuffersize = 1024 * 60;
public void UploadImage(Image image, string uri, string filename)
{
var request = WebRequest.Create(String.Format(#"{0}/{1}", uri, filename)) as FtpWebRequest;
if (request == null)
return;
request.Method = WebRequestMethods.Ftp.UploadFile;
request.Credentials = new NetworkCredential("userName", "password");
request.UsePassive = true;
request.UseBinary = true;
request.KeepAlive = true;
using (var writer = request.GetRequestStream())
{
var bytesData = image.ToByteArray();
var position = 0;
while (position < bytesData.Length)
{
var buffer = readData(bytesData, position);
writer.Write(buffer, 0, buffer.Length);
position += buffer.Length;
}
}
}
private static byte[] readData(byte[] bytesData, int position)
{
var buffer = new byte[defultbuffersize];
var lenght = position + defultbuffersize > bytesData.Length ?
bytesData.Length - position : defultbuffersize;
Array.Copy(bytesData.ToArray(), position, buffer, 0, lenght);
return buffer;
}
Extension method in an other class
public static byte[] ToByteArray(this Image image)
{
var stream = new MemoryStream();
image.Save(stream, ImageFormat.Jpeg);
return stream.ToArray();
}
Thanks in advance

The reason you lose transparency is found in your extension method
public static byte[] ToByteArray(this Image image)
{
var stream = new MemoryStream();
image.Save(stream, ImageFormat.Jpeg);
return stream.ToArray();
}
You are trying to serialize an png image using jpeg format
Change the extension method to this.
public static byte[] ToByteArray(this Image image)
{
var stream = new MemoryStream();
image.Save(stream, ImageFormat.Png);
return stream.ToArray();
}
This should fix your transparency problem.

How to get a photo from Server and display it in Image Control for Wp7

I am using the below code. I just dont know why it is not working. The error msg is : Unspecified error on this : bmp.SetSource(ms).
I am not familiar with HttpWebRequest for Wp7. Would appreciate your help to solve this problem. Thanks.
enter code here
private void LoadPic()
{
HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(#"http://xxxxxx/MyImage.jpg");
NetworkCredential creds = new NetworkCredential("Username", "Pwd");
req.Credentials = creds;
req.Method = "GET";
req.BeginGetResponse(new AsyncCallback(GetStatusesCallBack), req);
}
public void GetStatusesCallBack(IAsyncResult result)
{
try
{
HttpWebRequest httpReq = (HttpWebRequest)result.AsyncState;
HttpWebResponse response = (HttpWebResponse)httpReq.EndGetResponse(result);
Stream myStream = response.GetResponseStream();
int len = (int)myStream.Length;
byte[] byt = new Byte[len];
myStream.Read(byt, 0, len);
myStream.Close();
MemoryStream ms = new MemoryStream(byt);
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
BitmapImage bmp = new BitmapImage();
bmp.SetSource(ms);
image1.Source = bmp;
});
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}

Is it necessary to copy the response stream to a byte array and then to a MemoryStream? If not, you can just do the following:
Stream myStream = response.GetResponseStream();
Deployment.Current.Dispatcher.BeginInvoke(() => {
BitmapImage bmp = new BitmapImage();
bmp.SetSource(myStream);
image1.Source = bmp;
});
If you have to do the copy for some reason, you will need to fill the buffer in a loop:
Stream myStream = response.GetResponseStream();
int contentLength = (int)myStream.Length;
byte[] byt = new Byte[contentLength];
for (int pos = 0; pos < contentLength; )
{
int len = myStream.Read(byt, pos, contentLength - pos);
if (len == 0)
{
throw new Exception("Upload aborted.");
}
pos += len;
}
MemoryStream ms = new MemoryStream(byt);
Deployment.Current.Dispatcher.BeginInvoke(() =>
{
// same as above
});
Second part adapted (slightly) from C# bitmap images, byte arrays and streams!.

How do you retrieve a snapshot of a website in ASP.NET?

Could anyone tell me how I could retrieve an image or a thumbnail of a website through my ASP.NET application? I have seen this functionality in a few sites such as Alexa etc.

Try SnapCasa's free and easy to use service. Just form your image tag like this:
<img src="http://SnapCasa.com/Get.aspx?code=[code]&size=[size]&url=[url]" />
Requires sign-up, but it's free for 500,000 requests a month. [code] is an api key that they provide after sign-up. [size] is one of three sizes available. [url] is the website address to the site for which you want to display a thumbnail.
If you want to work with the image from your code, here are a couple of helper methods:
static public byte[] GetBytesFromUrl(string url)
{
byte[] b;
HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(url);
WebResponse myResp = myReq.GetResponse();
Stream stream = myResp.GetResponseStream();
//int i;
using (BinaryReader br = new BinaryReader(stream))
{
//i = (int)(stream.Length);
b = br.ReadBytes(500000);
br.Close();
}
myResp.Close();
return b;
}
static public void WriteBytesToFile(string fileName, byte[] content)
{
FileStream fs = new FileStream(fileName, FileMode.Create);
BinaryWriter w = new BinaryWriter(fs);
try
{
w.Write(content);
}
finally
{
fs.Close();
w.Close();
}
}
Then, in your code, just use:
//get byte array for image
var imageBytes = GetBytesFromUrl("http://SnapCasa.com/Get.aspx?code=[code]&size=[size]&url=[url]");
//save file to disk
WriteBytesToFile("c:\someImageFile.jpg", imageBytes);

Should be doable using a web-browser object and saving the view port to a bitmap resized to thumbnail.
I have not tested this code but try tweaking it after substituting for the thumbnail params.
using (WebBrowser wb = new WebBrowser()) {
wb.ScrollBarsEnabled = false;
wb.AllowNavigation = true;
wb.ScriptErrorsSuppressed = true;
wb.ClientSize = new Size(thumbInfo_viewportWidth, thumbInfo_viewportHeight);
if ((thumbInfo_Uri != null)) {
wb.Navigate(thumbInfo_Uri.AbsoluteUri);
} else {
wb.Navigate("about:blank");
HtmlDocument doc = wb.Document.OpenNew(true);
doc.Write(thumbInfo_HTML);
wb.Refresh(WebBrowserRefreshOption.Completely);
}
// create an image of the client area of the webbrowser control, than
// scale it down to the dimensions specified.
if ((wb.Document != null && wb.Document.Body != null)) {
Rectangle rec = default(Rectangle);
rec.Size = wb.ClientSize;
using (Bitmap fullSizeBitmap = new Bitmap(thumbInfo_viewportWidth, thumbInfo_viewportHeight)) {
wb.DrawToBitmap(fullSizeBitmap, wb.Bounds);
using (Bitmap scaledBitmap = new Bitmap(thumbInfo_width, thumbInfo_height)) {
using (Graphics gr = Graphics.FromImage(scaledBitmap)) {
gr.SmoothingMode = Drawing2D.SmoothingMode.HighQuality;
gr.CompositingQuality = Drawing2D.CompositingQuality.HighQuality;
gr.InterpolationMode = Drawing2D.InterpolationMode.High;
Rectangle rect = new Rectangle(0, 0, thumbInfo_width, thumbInfo_height);
gr.DrawImage(fullSizeBitmap, rect, 0, 0, rec.Size.Width, rec.Size.Height, GraphicsUnit.Pixel);
scaledBitmap.Save(thumbInfo_physicalPath);
}
}
}
}
}
One thing to note that it is an expensive process.