Prepare your images
It’s important to choose an appropriate size or resolution for your images before publishing them online. Learn some tips about preparing images.
Introduction
There are many phrases used to describe the quality of images which can be confusing. The two which are most important for online images are pixel size and compression.
Pixel size
You can view the pixel size of an image by viewing the properties of the file.
Usually you can do this by right-clicking on the image file and selecting Details. The exact method for doing this will vary by device.
You would typically see the pixel size shown as something like Dimensions: 3000 x 2000. Sometimes digital cameras, phones or tablets create images which are 'bigger' than this, which is when those numbers are higher.
We recommend that images are no smaller than 1000 pixels on the longest side. You will often see 'ppi' or 'pixels per inch' in relation to these measurements. For online images, this figure doesn't really matter, but it’s best to go no lower than 72ppi.
Compression
You will normally see the option to choose the compression of an image after you've edited it and are saving it.
Compression options are often shown as:
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A percentage.
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A number between 0 and 10.
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A number between 0 and 12.
We recommend no lower than 70% or 7 on the 0-10 scale. Or if your application uses the 0-12 scale, we'd recommend no lower than 8.
You can tell if an image has been compressed too much if you see bands of colour instead of smooth colour changes, such as in the sky of a landscape photo.
Saving images
After you resize an image, you'll need to save it.
You can save it as a copy to keep your nice high-quality photo safe on your computer for later use. Or you save it and overwrite the original image.
Most applications will show you the options for compression at this stage.
Image quality and eHive data allowance
You can upload images of a huge pixel size to eHive. Large images are great for zooming in to see small details. An example of where this is useful is on maps with small text.
However, uploading high-quality images will use your data allowance on your eHive plan more quickly. So it may be worth you making your photos a more modest size to strike a balance between image quality and your data allowance.
Software for editing images
Software that allows you to edit and manipulate your photos varies a lot. Free applications often disappear over time or become something you need to pay for.
The image editing programs that come with Windows or Mac computers usually allow simple functions such as cropping. However, they rarely offer the ability to control the pixel size or compression, and it’s easy to permanently alter an image into a state where the quality becomes too low.
If you have a digital camera, it's possible that it came with some free software.
Alternatively, the following applications are currently free.
This application functions very much like Adobe Photoshop. GIMP will allow you to do almost anything with your images.
This is a very powerful tool for working on images.
Tips
Resizing images can take a little practice. When you start learning your software it may be worth practising on some sample images first.
It can also be worth keeping the original high resolution images from a digital camera safe. This is especially important if they're produced by digitising old photos or objects which may deteriorate, making your digital photos the only remaining reference to the object.
Changing the pixel dimensions of your image and choosing the compression you wish to use alters the overall file size independently, meaning the amount of data your photo consumes. You can experiment with how to combine pixel size and compression together to manage the overall amount of data your images use.
