Front end developers may want to combine multiple images into a single image. For example, when creating and adding watermarks to stock photos, adding shapes or badges, preparing content for print (e.g. placing a logo on a t-shirt or a mug), adding a caption, and so on.
Many websites and mobile applications support user uploaded images and other files. This requires a service to receive and process the uploads, store them safely, transform them to match the website or app’s design, and deliver them to your users. This also requires a user interface within your site or app that allows users to easily upload images.
Many websites and mobile applications with user generated content allow you to upload all kinds of files. Images, PDFs, and Microsoft Office files, such as Word, Excel, and PowerPoint are all common types of uploads.
Web development was much simpler only a few years ago, when we were building HTML pages that included images and photos, and all elements shared the same resolution units. If for example, you aimed at a standard 1024x768 screen, you knew these were exactly the number of pixels available for displaying HTML elements and images.
If your web or mobile application involves user-generated content, you may encounter users who upload inappropriate photos or images to your application. These could be images which offend other users - adult content, violent photos, etc. - or images which cause your site to violate laws or regulations.
How do you crop an image to a custom shape? How do you add a shadow effect to an image with transparency? How do you add text overlay to an image without using HTML?
If you build or maintain a website with a lot of images, you've probably had many questions like these. Most developers who work with images have scripts or tools that can achieve dozens if not hundreds of image transformations - from basics like crop and resize, to advanced stuff like shadow and transparency, watermarks, face detection, etc. But how do you mix and match these transformations correctly to solve a problem or achieve a certain effect?
Fashion isn't something you'd expect to repeat itself in the technology world - technology advances quickly and hardly ever circles back. But where animated GIFs are involved, it seems like the 90s are here again. Animated GIFs are everywhere, and not only on strange, cheesy web sites - they've become mainstream. You now see short videos shared and played as animated GIFs in reputed sites such as Gawker and TechCrunch.
Image optimization is an important step to reducing page load times, improving user experience and reducing bandwidth costs. When using the JPEG image format, which is best used for photos, the most common optimization is controlling the JPEG quality level.
It’s a common challenge in many mobile and web applications: how do you allow users to upload their own images, while automatically adapting these images to a fixed graphic design?
A classic example is a user uploading a profile picture, but instead of providing a headshot (which is what we really need from them), they upload a picture of their entire body with additional objects in the background. Obviously this image will need to be cropped to the size of the profile picture, while focusing on the user’s face.
There are many ways to optimize PNG files, but one optimization which is commonly overlooked involves the PNG's transparent background. If you’ve chosen to use PNGs instead of a more compact format like JPG, mainly for the PNG's support of a transparent background (alpha channel), read on and see how dynamic underlays can reduce your file size by as much as 1:5.