Determine image weight

YoungLuke · November 19th, 2007, 06:33 PM

hello, i want to load an image from a website using either httpwebrequest or the webclient, and determine the image size from the request/client.

example:

image located at http://test/site/I/test.jpg

use the httpwebrequest to determine the image size and weight?

planoie · November 20th, 2007, 12:35 PM

I don't think you'll be able to do this with httpwebrequest alone. You can use that to GET (literally) the image data which you could then load into the Image .NET class. From there you can interrogate the class' properties.

-Peter

dparsons · November 20th, 2007, 01:16 PM

To demonstrate what Peter is saying you could do something like this:

Code:

        WebRequest objRequest = WebRequest.Create("http://test/site/I/test.jpg");
        objRequest.Method = "GET";

        WebResponse objResponse = objRequest.GetResponse();
        System.Drawing.Image b = System.Drawing.Bitmap.FromStream(objResponse.GetResponseStream());

the instance B will now contain the Width, Height, etc about your image, however, you can NOT get the file size of the image from the Image class. You have 2 choices here:
Save the file to disk and use the FileInfo class to get the file size or a slightly less accurate method would be to convert the image into a Byte array and get the length of that array to get a determined file size.

hth.

--Edit:
To the end of using the HttpWebRequest/Response classes, you can declare objRequest and objResponse as an HttpWebRequest and HttpWebResponse respectively but you would modifiy the code:

Code:

HttpWebRequest objRequest = (HttpWebRequest)WebRequest.Create("http://test/site/I/test.jpg");
...
HttpWebResponse objResponse = (HttpWebResponse)objRequest.GetResponse()

hth.
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samjudson · November 26th, 2007, 05:13 AM

You might be able to check the ContentLength on the HttpWebResponse, but depending on how the server serves up images this might be the filesize, or might be 0 or -1. You can try setting HttpWebRequest.Method to "HEAD" and then checking the ContentLength on the HttpWebResponse if you only want the filesize.

/- Sam Judson : Wrox Technical Editor -/

YoungLuke · November 26th, 2007, 05:34 PM

Thanks!

i'm able to get the weight of the image from the content parameters of the webresponse object and get the dimensions from the image object.

Thanks everyone!