Change the background of the image in the reports

I have a report using Crystal Report, I select a specific position of an image within the report and add a default image to the Picture tool.
What I want is to change the image inside the image box with the code. Use the following method to change the text inside the text box on the report.
What is the way to change the image??

crystalreport.CrystalReport1 crv = new crystalreport.CrystalReport1();  
TextObject TextEedit;  
                    TextEedit = (TextObject)crv.ReportDefinition.ReportObjects["Text1"];  
                    TextEedit.Text = "good";