This refers to Moodle 3.4 from September 2018 onwards
This is a simple tutorial about how to reduce download speeds in Moodle by making your images' file sizes smaller
Whether you are uploading images, graphics or pictures directly, or including them in documents or presentations, there are a few recommended preparations to make to optimise image upload and download.
The best way to reduce image downloading times is to create smaller files. Older file types, such as BMP files, can be quickly converted to modern files types with substantial file size decreases. Saving images as JPG or PNG files is usually best. JPG is the most common file format used on the internet for reasons of efficiency: although there is a loss of quality involved, it is usually only noticeable where there are large blocks of colour or if the 'compression rate' of the file is set too high. If you do not want to lose any image quality but still want file sizes as small as possible, the PNG format is your best bet. It is hugely more space efficient than BMP files.
How to save files as different formats (PC)
The simplest way to change file format is to open your image in Microsoft Paint. This can be found under All programmes > Accessories > Paint. Once the image is loaded, you can choose Save as and then select the format you need:
Another option to consider is one of the many online services that will reduce file sizes for you. One quick, convenient and free online service is Image Optimiser - http://www.imageoptimizer.net/ You upload the file you wish to reduce in size and choose the level of optimisation required. Usually, the higher the level of optimisation, the smaller the file size, but with lower image quality, so some experimentation may be required. Please note, you may need to change the maximum width and height options (if they are higher than the default) to avoid the image being skewed.
Another way to reduce the file size is to make the dimensions of the image smaller. This is worth considering if you want faster PowerPoint or web page display times too, as the software has to do less work to the display the image.
How to resize an image (PC)
Microsoft Paint is a simple way to reduce an image size. Choose Select then choose the option Select all. This will allow you to ensure all of the image changes size.
Next, you need to choose Resize, and in the box that pops up choose to resize by percentage (if you are unfamiliar with dimensions described with the term pixels). It is important to ensure the box Maintain aspect ratio is ticked to keep the image from skewing.
Now save the image, ready for uploading into Moodle
Open the File menu
Click Save As