this.cwb_chart1.SaveImage(stream1, ImageFormat.Png);sheet.Pictures.AddPicture(4, 2, stream1);
We are able to reproduce the issue. So we have logged defect on this “Chart export image size not proper resolution in Excel” with new incident 143155. A support incident to track the status of this issue has been created under your account. Please log on to our support website to check for further updates
Please let us know if you have any concern.