![]() ![]() ![]() This could already be a reason to use PDFs instead of SVG if your app is supporting targets lower than iOS 13, iPadOS 13, or macOS 10.15. ![]() Single scale PDFs are introduced in Xcode 6 and are supported since iOS 8 and OS X 10.9. You simply drag the file into your Assets Catalog after which you have to change the Scales option to “Single Scale”:Īfter that, you can use your SVG Image Asset just like any other asset. You can learn more about SFSymbols in my blog post SF Symbols: The benefits and how to use them guide. This takes away some extra space in your app bundle. SFSymbols have the same platform version availability and are available as system images. If your app supports any older version you should not use single scale SVGs.īefore you start replacing all your assets with SVGs you might want to consider using SFSymbols instead. It’s important to point out that SVGs are only supported on macOS 10.15 or later, iOS 13 or later, and iPadOS or later. If you have a logo, icons, or symbols, you can most likely look into replacing them with an SVG asset. Rich assets like images with lots of details should still be defined as individual scales. SVG assets can not be seen as a replacement for all your assets. It’s mostly used for icons and symbols and allows platforms to scale up the asset for the current active resolution. Scalable Vector Graphics, also known as SVG, defines two-dimensional graphics defined in Extensible Markup Language (XML). Stay ahead of the curve and build with unwavering confidence. Scale: CGFloat = CI solution with Xcode Updates delivered within 24 hours of release You're equipped with the latest technology for your builds. The following code snippet demonstrate how to perform downsampling on an image: func downsample(imageAt imageURL: URL, What is so great about the ImageIO approach is that we can now resize an image by only paying the cost of the resized image. We can use the ImageIO framework to resize an image before showing it on screen. Luckily for us, the WWDC video does provide a great solution to the problem that we are facing. During the resizing process, iOS will still decode and decompress the original image, thus causing an unwanted memory spike. This is because UIImage is expensive for sizing and resizing. Which does add up to what we saw in the memory report.Ĭool! We have figured out where the memory usage comes from, but how can we reduce the memory footprint to an acceptable level?Īs I mentioned earlier, we try to scale down and redraw the image, but that doesn’t seem to help. Takes our sample image with dimension 3648px × 5472px as an example: (3648 * 5472) * 4 bytes ≈ 80MB Typically, 1 pixel of a decoded image will take up 4 bytes of memory - 1 byte for red, 1 byte for green, 1 byte for blue, and 1 byte for the alpha component. Yes I know, the video is from 2018, but it’s never too late to learn, right? □Īccording to the video, in order to show an image on screen, iOS will first need to decode and decompress the image. Memory use is related to the dimensions of the image, not the file size. After a few Google searches, I ended up with an amazing WWDC video that introduced a very important concept that we all didn’t know about: Without having any clues on how to fix the problem, I head over to the web. One approach we take to tackle this problem is to scale down the image and draw it on screen based on the image view’s frame size, unfortunately, that doesn’t seem to fix our problem. This doesn’t make sense at all! We are loading a 2.4MB image file, how does the memory footprint get so high? Where does all this memory usage come from? □ Memory footprint when load HD image on screenĪs you can see, the memory usage spikes up from 8MB to 87MB after the image is loaded. ![]()
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