If you request a pixel size of 1 m, then they will be read as having the same pixel size. For example, let’s say you have three images with pixels that are 0.95 m, 1 m, and 1.05 m and your tolerance factor is 0.1. Note that pixel size in a mosaic dataset is based on a tolerance factor. If two images have the same ZOrder value, the tie breaker is based on pixel size. Once seamlines are created, the ranking order is populated in the SOrder field, with smaller values taking precedence. This is a good practice if you want to mitigate artifacts that are created from the boundaries of neighboring or overlapping rasters. The third option, Closest to Seamlines, works only if you have generated seamlines and only as a tie breaker for ZOrder. Option 3: “I want my imagery to look as smooth as possible.” The only difference between SOrder and ZOrder in that 0, or, will be at the bottom of your image stack.
SOrder is populated after you generate seamlines, and ranks items based on the distance to those seamlines. To reiterate: it’s here if you want total control over the display order. All items are listed as by default in ZOrder, so if you want to don’t want to wade into this, you don’t have to. If you want to change the ordering, we suggest using negative values to push a specific image to the top of the list. In ZOrder, 0 functions as a and will display before any items with positive values. With any of the following options, ZOrder is the principal deciding factor, and the other methods only come into play if the ZOrder is equal. Items with the lowest value in the ZOrder column will be at the top of your image stack (displaying first) and the highest values will be at the bottom of your stack (displaying last). You can edit this field in the table to change the ordering of items in your image stack. ZOrder gives you total control over the ordering of items in your image stack. The image on top of the stack is what is visible, those at the bottom would be the last to display. Talking about ordering can get confusing, so it’s easiest if you imagine all of your overlapping images as part of an image stack.
Both of these are columns in the table that rank the order in which the items will display. Right? Well now there’s a couple of concepts that you need to wrap your head around. Intermission: “ZOrder? SOrder? Are these action heroes from a planet not in this solar system?” Populate the list, and only those rasters will display. Choose this option when you know the specific raster IDs that you want to show. Option 2: “I know which images I want to look at, forget the rest.” None is suitable when you’re cataloging your imagery collection, and it’s not important which layers are displayed on top. Option 1: “Quick and easy, no thinking required.” And for those of you who like to learn verbally, enjoy the rest of this blog.
For you visual learners out there, enjoy the following flow chart. I’m hoping we can clarify some questions that have come up with regards to how display ordering occurs with mosaic datasets. If you’re working with huge mosaic datasets, with hundreds or even thousands of rasters, then this blog is for you.
0 kommentar(er)
