Hi John,
Considering you are using Report API, you can specify the TitlePage object's Image property as a DOM Image object instead of the image path. The DOM Image class has properties to specify custom height and width. With DOM Image, you can also use ScaleToFit format to automatically scale a large image to fit the page boundaries.
Below is an example that adds a custom size image to the title page:
% Create a report
rpt = mlreportgen.report.Report('output','pdf');
% Create title page
tp = mlreportgen.report.TitlePage();
tp.Title = 'Title Page Example';
tp.Subtitle = 'Report API';
tp.Publisher = 'MathWorks';
tp.PubDate = date();
% Add a custom size image to the title page
domImage = mlreportgen.dom.Image(which('b747.jpg'));
domImage.Height = '3in';
domImage.Width = '3in';
tp.Image = domImage;
% Add the title page reporter to the report
add(rpt,tp);
% Close and view the output document
rptview(rpt);
Thanks,
Rahul
