![]() Smaller tiles are usually problematic as the TIFF directory size might explode, larger tile size can be useful together with JPEG compression and very large files since we might loose some CPU cycle but reduce the impact of slow storage/large files.ĭeciding when to go beyond and use mosaicking plugins ¶Īs long as the size of the dataset (again, beware that proper compression can help greatly to reduce the size of the disk) is reasonable (by experience below 20 to 30 GB) with respect to the disks speed we can use individual geotiff for our datasets without problems. The default for GDAL is 256x256 but it is not unusual for us to set this to 512x512 on large bigtiff files. If the tiles are too small, for large tiles the page directory might explode and become slow to scan for the Tiff reader, on the other side a tile that is too big will make the directory small and fast but might end up in too much data to read for most operations. seeks and load) and the amount of storage we might waste when the file size is not a valid multiple of the tile size on both side. Splitting the file in proper tiles is important to minimize the amount of data we read/write on each requests, the number of read operations (i.e. Let us dig a little deeper on this subject.Ī GeoTiff can contain multiple pages/images, each page/image starts with what is called the image directory which contains various info about the current page in such directory we have 2 arrays of integers (for bigtiff are long) which contains the location on the disk of the tile and its size in bytes. There is no mathematical rule to decide the tile size for inner tiling. ![]()
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