Image sizes

It often happens that a scanned image or a photograph taken with a digital camera is too large as to its pixel count. When the amount of pixels is too large, publishing it on e.g. a web page may cause problems for anyone viewing the web page. In addition, very large images spend a considerable amount of storage space and loading them over slow web connections takes a very long time. This is why it is a basic image-processing skill to know how to decrease the file size of an image.

Selecting a suitable image size

You can use most image-processing programs to change the size of an image, i.e. decreasing or increasing the number of horizontal and vertical pixels in an image file. Before resizing an image you need to check how many pixels there are in the original; with Paint Shop Pro, you can see the size of an image in the lower right-hand side of the image. In the example below, the values 3510 and 1040 show that the image consists of 3510 horizontal and 1040 vertical pixels. This image is very large for publishing on the web.

When you open an image with an image-processing program, the program will usually fit the image to your screen. This does not mean that the size of the image itself changes.

So how much should you decrease the size of the image in the example above? You can follow the rule of thumb that the horizontal and vertical resolution of the image should be chosen according to what it is to be used for. In web publishing, for example, you should fit the horizontal resolution to the browser window. This means that it should be around 1000 pixels; an image that is much more than 1000 pixels wide will often be too large while one that is much less than 1000 pixels wide will be unclear and the details hard to make out. In the case of the example, minimizing it to about half the horizontal and vertical pixels will likely be a good choice.

Changing image sizes

To change the size of an image with Paint Shop Pro, open the image and then give it the Resize command in the Image menu. This will open up a menu window (see image below) where you can specify the size of the image. To decrease it by half, set the value 50 % under Pixel Dimensions. To finish, click on OK.

The feature now decreases the size of the image. When you have changed the size, check how the change has affected the image quality and size: check the size again in the lower right-hand corner.

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Please note that the storage capacity the image needs depends on the file format you have used (e.g. JPEG and TIFF are very different when it comes to storage space) and that you will not find out the required storage space until you save the image. Always check the size of an image before publishing it on the web or sending it by e-mail.