You will need
- program Adobe Photoshop.
Determine approximately the percentage necessary to increase the photos. If it is the color – it is not recommended to increase the size more than 10-15%. It is impossible to say because each image is an individual case. Here we must consider not only the initial size, but the format and quality of file. For example, clear black and white jpeg is quite possible to increase even 50 %, but a color image, which contains few pixels per inch, is unlikely to increase at all. Also important factor is the content of your images. If it is characterized by the presence of small parts, a manifold increase is not recommended.
Edit the image before you resize it. Remove all existing defects with the help of special tools in the left pane, because after enlarging the picture the impact of the image will be very noticeable. For the convenience of the zoom the image using the Navigator in the menu "Window". Achieving the desired result, make a copy of this file by saving it.
Resize the image by selecting the appropriate item in the edit menu and select the desired magnification. It is best in this case to use bicubic smooth proportion. Set the image quality from 150 and above, if it is intended for photo printing.
Review the result, if necessary, paint on lines in places where they are not enough. Point sharpness so that the image quality is not conspicuous. Experiment with the brightness-contrast for each image, you can find a way if you wish. If you have to edit the image, increase it initially by 2% more than required, edit, and then reduce.
Before using special software to enlarge photos try to do this operation manually.