Reducing file size by optimising images

One of the many problems with images and their storage in Microsoft Office documents (Word, Excel and PowerPoint), is the lack of understanding of how this data is stored and the impact that this can have on the disk space used to store the document.

For instance imagine we import a picture into word which is approximately 1 Megabyte in size on disk and 2514 x 1686 pixels in size on screen.

Right clicking on the image and selecting format picture, then selecting the size tab will reveal that this has already be reduced in size on screen to 22% of its original size.

However when this word document is saved, you will see that the files is still over 1 Megabyte in size.

Microsoft Office 2013 has a system to compress images built into it. You should notice that when you select the image on screen a new Ribbon option appears labelled Picture Tools – Format

With the image selected click the Compress picture button shown below:

Clicking this button should bring up the following screen:

Using our example if we compress the map for print reduces the save document to 20% of its original size, in this case a saving of 800 Kilobytes, and selecting the compress for Web/Screen reduces the file to 67 Kilobytes (nearly one twentieth of the original size) without reducing the quality noticeably.

 The same process works in PowerPoint and Excel.