UIImageRenderingMode

UIImageRenderingMode is a property of the UIImage class in iOS, which determines how the image is rendered on the screen. It was introduced in iOS 7 as part of Apple's efforts to reduce the impact of older images on the overall performance of the app.

The UIImageRenderingMode property allows developers to specify how the image should be drawn, especially when the image is a template image, which has a transparent background. When UIImageRenderingMode is set to UIImageRenderingModeAlwaysOriginal, the image is drawn at its original resolution, without any loss of quality. This mode is suitable for images that require high levels of detail and texture.

On the other hand, when UIImageRenderingMode is set to UIImageRenderingModeAlwaysTemplate, the image is drawn with a solid color background. This mode is suitable for images that have a transparent background and require a simple background color.

UIImageRenderingMode also provides control over how images are rendered when they are scaled up or down. When an image is scaled up, interpolation can create aliasing artifacts, which can be undesirable. By setting UIImageRenderingMode to UIImageRenderingModeAlwaysOriginal, these artifacts can be minimized, resulting in a higher-quality image.

It's worth noting that UIImageRenderingMode only affects images that are loaded from assets and does not affect images that are stored in memory. Developers can use UIImageRenderingMode to take control over how their images are rendered and improve the overall performance and quality of their app.