Image Pyramid is a collection of images with a series of resolutions from fine to coarse generated according to certain rules. Image Pyramid technology establishes a series of Image Layers with different resolutions through the Image Resampling Method. Each layer is divided and stored, and the corresponding Spatial Index mechanism is established, so as to improve the Display Speed when zooming and browsing images. For the Image Pyramid shown in the figure below, the bottom is the representation of the original highest resolution of the image, which is 512 × 512 image resolution. The higher the image is, the smaller the resolution is, which is 256 × 256 and 128 × 128 respectively. The top is the image with the lowest resolution of Image Pyramid, which is 64 × 64. So this Image Pyramid has four layers, or four levels of resolution. Obviously, the higher the image resolution of the image, the more levels the Image Pyramid has. For an image with an image resolution of 2a × 2b (a > B), a pyramid of (b-6) + 1 layers will be established in SuperMap.

Figure: Image Pyramid

After you create an Image Pyramid for an image, each time you view the image, the system fetches its Image Pyramid to display the data. When you zoom in or out of an image, the system automatically selects the most appropriate pyramid level to display the image based on the user's Display Scale.

Pyramids can only be created for raw data. Only one DatasetCreate Pyramid can be given at a time. If you want to create it again, you need to delete the created pyramid. When you browse the Raster Dataset after the Create Image Pyramid, you are actually accessing the pyramid you have created. As shown in the figure below, the pyramid is built at different scales.

Create Image Pyramid can significantly improve the speed and performance of image zooming display rendering, but at the same time, the establishment of Image Pyramid will increase the storage space of the Dataset, that is, the size of the Datasource file where the Image Dataset is located. This is because the created Image Pyramid is actually a collection of images at different resolutions, and these images at different resolutions are stored in the Datasource file together with the data, thus increasing the size of the Datasource file. Moreover, the larger the amount of Raster Dataset data, the longer it takes to build the pyramid, and the larger the storage space of Image Pyramid, but it will save more time for future image browsing. Therefore, for massive Image Data, Create Pyramid is a choice to optimize efficiency.

SuperMap SIT image fileS torage Format is a data format that integrates image compression and efficient Image Pyramid technology, so it can display Image Data very quickly, regardless of the size of Image Data. Massive Image Data can be displayed very smoothly even on a machine with very low configuration.