In the user flow above, the end user is requesting for a cropped and optimised image. Using Akamai Image Manager Request Flow as an example Sitecore Image Compression and Next-Gen Conversion.Dianoga - massive shout out to current maintainer Mark Gibbons.Other notable tools that are in the Sitecore Community: Sitecore also provides Responsive Image field and variant field in Sitecore Experience Accelerator as of v1.7. The only issue I am seeing is that if the hash that is supplied is not correctly validated, it returns the full image, which can slow down Sitecore / IIS as it is busy slowly serving out all the bytes down the tube. For older versions of Sitecore, you can check out If this querystring parameter is available, the CDN cache should be set to a very long time. Media.AlwaysAppendRevision (available as of 8.2.5) - this should always be true to form part of CDN cache key.Use HighQualityBicubic for best quality, especially when using CDN to optimise images Media.InterpolationMode - The interpolation mode to use when resizing images.Use HighQuality if using CDN to optimise images - Specifies how pixels are offset when resizing images as the offset affects resizing speed.- Specifies how the source colours are combined with the background colours when resizing images.- Specifies the level of compression to use when resizing images.If the requested width exceeds this value, Sitecore resizes the image to this width. / - Maximum width for dynamically resized images. There are some interesting Out-of-the-Box settings available and definitely worth taking a look: Image Resizing query string parameters are used to resized / transform images. Sitecore has image resizing capabilities and optimisations since v6.x. However, the perceived experience for a user to see a full image earlier is a good trade off, and is also considered as a higher score when it comes to site speed audits. Progressive JPEGs are usually slightly larger in file size compare to Baseline JPEGs. Progressive JPEG loads from low quality to high This will give user a perceived experience to see the image with a full context whilst loading. One interesting technique is to use Progressive JPEGs instead of Baseline JPEGs. This often introduces additional load to hardware resources when optimisation is automated. Automated tools are often run on pre-processing, meaning optimisation is done before images are stored, or on the fly, meaning the optimisation is only run and then stored in cache when requested. Usually, they include removal of Meta / EXIF data, transferring Progressive JPEGs, and apply a predefined level of image quality using either lossless / lossy tools. More automated tools can combine a few number of techniques all in one command. This creates another 2 to 3 variations required for each image crop. Image file sizes generally are reduced by 15–25% when using NextGen format. Modern browsers support NextGen image formats (eg. Images with very heavy Red / Orange / Pink colours are very difficult to optimise without losing quality. Appropriate Disk storage is also required to store all variations with the appropriate file names. However this is a tedious task to provide different sizes of images. There are many image optimisation techniques available to produce lower image file sizes.Ī designer can go through all the images, resize / crop them accordingly, using the naked eye to judge the lowest image quality to use without sacrificing quality. Site speed affecting conversion hypothesis has been tested to death already. Slower web sites also affects user conversion. Non optimised images will slow down the site, which has an effect on general site speed, and affects SEO site ranking. Increasingly, users are browsing using their mobile phones over a cellular network. Online consumers and users often rely on images to help them make purchase, or user journey onward decisions. Responsive web site designs catering for different types of devices.Approximately 63% page weight are images.A web site often has images to help convey the message. A picture can convey an emotional context, with background settings. Barnard, 1920Īs we all know, a photo / picture can communicate to the audience in so many ways. A Picture Speaks a Thousand Words - Fred R.
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