Let's take a look at what the USA user said:
No sweat, no pixellation or graininess, everything smooth, looking as good as the smaller original. Four times bigger, no problem. This app does it with no fuss, simply follow the directions: "drop an image here" --Simonett
HQ Photo Enlarger is a program that produces enlargements dramatically sharper than other software.
The program offers an innovative image enlargement algorithm which results in perfectly smooth and crisp edges. And it can simulate the texture and film grain which keep photos looking natural even in extreme enlargements.HQ Photo Enlarger beats any of the alternative solutions, such as Photoshop's Bicubic technique, Bilinear methods, and so-called 'industry standards'.
• Get smooth and crisp edges in the enlarged images.
• Deal with five different algorithms at the same time, and it is easy to compare five types of enlarged images on the interface.
• Batch process multi-images with one click.
• 20 pre-defined algorithms, and you can also customize the new algorithm with different parameters.
• Support input and output image formats: jpg, png, bmp, tif, ppm.
The final size of the saved image is based on how far you're zoomed in on the image in the preview window- so watch that you zoom to your desired size before saving. It will be a great tool for people who are looking to print in a larger size but unsure if their photo will hold up.