Using Irfan View to resize your photos
Before you can edit your photos in Irfanview, you need to install the program on your pc. You can download it here from their official website.
After you have installed Irfan View on your computer, do the following:
Click on open and on the Common Graphic Files arrow.
This is the page on which you can see what type of photo or image you would like to load into the program. As you can see the program can work with nearly any type of image.
Load the graphic you wish to work on, click on Image on the menu and click on Resize/Resample on the drop down menu.
In the window that opens up you have a few possible settings you can use. In this window you can resize the image to a normal desktop size such as 1024 x 768 pixels. This is usually the desktop size you use, or sometimes a bit larger. This is however, a good size to email an image or photo for normal printing on items not larger than A4. For large format printing (banners, posters or signage), I suggest you send the image as large as you can.
You can also adjust the size by changing the DPI (dots per inch). Making a small photo 300 dpi, it will print without any pixelation. If you are only using it for viewing on a computer, keep it at 72 dpi.
You can also change the size manually by typing in the size in either pixels or centimeters, or you can make it half the size with one click on the button provided.