Should ToBase64String() method work with all image types?

Question

I have been using the conversion method ToBase64String for some time now without any issues until now. I am basically taking an uploaded image, converting it to a byte array and then using the ToBase64String() method combined with the identified content MIME type to assign to an image tag's source on my page. Here is my method:

    protected string RenderImage(byte[] image, string contentType)
    {
        try
        {
            if (profilePhoto != null)
            {
                byte[] byteArray = image;
                string imageBase64 = Convert.ToBase64String(byteArray);
                string imageSrc = string.Format("data:"+ contentType +";base64,{0}", imageBase64);
                return imageSrc;                    
            }
        }
        catch (Exception ex)
        {
            // Catch Exception
        }
        return null;
    }

I am working in the MVC framework so I am assigning the returned value as the source of my image tag within a successful ajax function call. A snippet of the code:

success: function (result) {
     var newImg = document.getElementById("updatedImage");
     newImg.src = result;
}

This has been working fine but lately I've noted that image/png and image/x-png MIME types have not been rendering successfully using this method. I've compared the attributes of these images with attributes of those which have no problem and I can't find any significant differences that would explain the problem.

I have also noted that the problem isn't prevalent with JPG files and if I simply assign a direct path to the png file as the source, the file renders appropriately in the image tag.

I seem to have a knack for running into oddities like this but was hoping someone may be able to give some input as to why this may be occurring.

I would think that the image tag should be able to handle any string provided by the Convert.ToBase64String() method as long as the size of the byte array was within a reasonable limit. And these PNG files are relatively small anyway. About 49KB in size with dimensions of 232 x 232.

Answer 1

How are you getting the image string?

This sounds like a GET size limit issue where the server silently truncates the response.

To troubleshoot this further... I would look at the base64 string you are getting via ajax and compare that to the actual image toBase64 inside your method.