Visuals are used to attract attention but also to provide information. Data visualization is a basic skill of data scientists, helping them tell the story behind the data.
The popularity of infographics and data visualizations on the Internet has grown exponentially in the last years. According to a report from Infographic World, visuals improve information retention by 400%. However, attractive images and graphics can be large in size and slow down your website. Therefore, it is crucial to optimize the images for web usage. Read on to learn more about image optimization for data visualization.
What Is Data Visualization?
The term data visualization refers to the techniques and processes used to communicate information via visual content. Data scientists use graphs, charts, and infographics to convey information in a clear way.
Presenting analytics visually often helps users understand complex concepts. Professionals often use data visualization to detect patterns in the data.
Data visualization goes beyond the realm of data science. Often, companies use data visualization to identify trends in the market. Other uses include tracking performance or calling attention to an issue. Data visualization is also part of a new branch of journalism called data journalism.
Why Visualizations are Viral
Displaying data visually is often the most efficient way to convey complex information. The preference of Internet users for visual content proves it. A study by the Universities of Oxford and Harvard has proven that the use of smartphones shortens the attention span of users. This impacts the time users wait for a website to load, as well as the time a website has to catch the user’s attention. In addition, people retain visual content longer than they retain written content.
What Is Image Optimization?
Image optimization is the process of providing high-quality images through the Internet while keeping the images’ size small. This is important because larger images tend to slow the page load time.
According to research by Google, visitors stay 70% longer in sites that load in less than five seconds. The bounce rate jumps to 32% for pages that take more than five seconds to load. This means that if your visualization takes too long to load, chances are that users will leave the page.
When preparing charts and images for data visualization, you should understand how images are stored. There are many image file formats, each with its advantages and setbacks. Using the right file format can reduce the image size and avoid quality issues.
Images can consist of bitmaps or vectors. Bitmap images are comprised of pixels ”a single point in an image, that carry a given color. Vector graphics consist of lines that create the image. The main advantage of vector graphics is that they can be enlarged without losing sharpness.
The most popular of vector graphics are Scalable Vector Graphics, which are used mostly for online content. However, vector graphics tend to grow to large file sizes for large datasets.
Among the bitmap images, JPG is the most popular. This format supports a wide color palette and is optimized for photos. PNG format is suitable for line drawings and simple lines as it tends to be larger in size.
3 Image Optimization Methods
1. Resizing
This method consists of reducing the size of the image in pixels. This often includes tweaking the length and height. However, resizing usually degrades the image because reducing pixels affects the resolution. You can also resize by reducing the pixels in the image.
2. Compression
Images consist of pixels. You can reduce the file size by compressing the pixels in it. Image compression removes extra data, by homogenizing the color differences in the image. However, compressing an image usually affects image resolution.
There are two main types of compression, lossy or lossless. Lossy compression removes the extra data permanently. On the other hand, lossless compression reduces the size without affecting the image quality.
3. Caching
Unlike the previous two, this method does not affect the image size. Caching is the process of storing the image files on a browser’s cache. This reduces application requests. Less application requests means faster access to the images and reduced loading times.
6 Tips to Optimize Your Images
1. Choose the right format
Changing the file format can help you reduce the size of an image.
2. Caption the images
Captions are texts that appear below the images, functioning as labels.
3. Provide accessibility through alt text
Alternative text is a short description of an image. It is mostly used by accessibility readers that read the image to visually impaired users.
4. Use progressive loading
Progressive loading consists of rendering an image in layers. The website first loads a pixelated version, which is later replaced with successive better quality layers.
5. Enhance the images
You can use an image editor or an image optimization tool to modify the background or sharpen the contrasts.
6. Use a Content Delivery Network (CDN)
The term CDN refers to a network of servers that deliver web content according to the geographic location of the end-user. Typically the closest server delivers the content.
The Bottom Line
An effective data visualization requires more than engaging images. Providing a good user experience for the visitor is crucial to convey the message behind the data. Therefore, applying image optimization can help you overcome the challenge of combining attractive images with a fast-loading page.
