in php how to download Image and at the same time display that image in browser using header?

I am applying watermark to the image using php where after uploading the image the fixed watermark gets glued to the image and in the last I can able to display the image or I can able to download the image but I want to do both the things at the same time

this code shows me the image at the last

header('Content-Type: image/jpeg');
imagejpeg($new_canvas, NULL , 90);

this code download the image at the last

header('Content-Disposition: Attachment;filename=image.jpeg');
            imagejpeg($new_canvas, NULL , 90);

but I am not able to do both the things together?

I tried this but no result

header('Content-Type: image/jpeg');
 header('Content-Disposition: Attachment;filename=image.jpeg');
                imagejpeg($new_canvas, NULL , 90);