How to Add 'Comments' to a JPEG File Using C#

Question

Within the property window of a JPEG image, there is a tab called \'Summary\'. Within this tab, there is a field called \'Comments\' I would like to write some c# code which

Answer 1

Thanks to the previous tips I was able to put the following together. I've tested it and it seems to work. One of the biggest stumbling blocks was determining the Id needed for the field you want to assign.

string fileName = "c:/SomeImage.jpg";
// Retrieve the Image
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(fileName);

// Get the list of existing PropertyItems. i.e. the metadata
PropertyItem[] properties = originalImage.PropertyItems;

// Create a bitmap image to assign attributes and do whatever else..
Bitmap bmpImage = new Bitmap((Bitmap)originalImage);

// Don't need this anymore
originalImage.Dispose();

// Get / setup a PropertyItem
PropertyItem item = properties[0]; // We have to copy an existing one since no constructor exists

// This will assign "Joe Doe" to the "Authors" metadata field
string sTmp = "Joe DoeX"; // The X will be replaced with a null.  String must be null terminated.
var itemData = System.Text.Encoding.UTF8.GetBytes(sTmp);
itemData[itemData.Length - 1] = 0;// Strings must be null terminated or they will run together
item.Type = 2; //String (ASCII)
item.Id = 315; // Author(s), 315 is mapped to the "Authors" field
item.Len = itemData.Length; // Number of items in the byte array
item.Value = itemData; // The byte array
bmpImage.SetPropertyItem(item); // Assign / add to the bitmap

// This will assign "MyApplication" to the "Program Name" field
sTmp = "MyApplicationX";
itemData = System.Text.Encoding.UTF8.GetBytes(sTmp);
itemData[itemData.Length - 1] = 0; // Strings must be null terminated or they will run together
item.Type = 2; //String (ASCII)
item.Id = 305; // Program Name, 305 is mapped to the "Program Name" field
item.Len = itemData.Length;
item.Value = itemData;
bmpImage.SetPropertyItem(item);

// Save the image
bmpImage.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg);

//Clean up
bmpImage.Dispose();