Tag: raster function
Use a newly available Aspect-Slope Raster Function that can be downloaded from Esri’s GitHub repository for raster functions to quickly and easily create an aspect-slope map from raster elevation data. Continue reading
The Processing pane on the Image Analysis window contains various tools that can instantaneously process your data on-the-fly. However not all of the button are active all of the time. This is because each tool is dependent on the layers … Continue reading
Here is a link to an Applications Prototype Lab (APL) blog post in case you missed it. This blog shows you chained raster functions doing server-side analysis in a web application.
There are several ways to persist your Image Analysis results.
The Apparent Reflectance raster function calibrates image brightness values (DN) for some satellite sensors. The main advantage of apparent reflectance function is to adjust the images to a theoretically common illumination condition, so there should be less variation between scenes from different dates and from different sensors. This can be useful for image classification, color balancing, and mosaicking.
Last week’s Imagery Blog discussed what a raster product was and why they are useful.
If you would like to see a video about raster products, there is one available on the ArcGIS Resource Center.
At ArcGIS 10.1, we introduce a new concept called a raster product. A raster product is a new and easier way to handle specific vendor data. Most vendor products are distributed with each band as its own file. This meant that you had to process the data before you could use it as one raster dataset.
Calculating statistics are not always required after you apply a function. However, there are times when it may be helpful or even required.
When are statistics required?
Color correction requires up-to-date statistics. Therefore if any functions have been applied to your mosaic dataset, since statistics were last calculated, you will need to calculate them again.
When are statistics a good idea?
Often times when you apply a function, it can change the (virtual) pixel values. If you want to keep your mosaic dataset using the most accurate statistics and rendering, then you will need to calculate statistics again.
For instance, when you use the Stretch function to map your 8-bit data to a 16-bit pixel depth, your images will probably show up black, unless you calculate statistics.
Written by: Simon Woo and Jie Zhang
Is your mosaic being mosaicked in the proper order when you are using the Image Analysis window?
The Image Analysis mosaicking order is determined by the mosaic operator that you choose, and the order of the rasters in your Table of Contents. The order that you selecthighlight the rasters in the Layer List is not taken into consideration.
If you have made any changes to the default raster type, you will probably want to save your changes. This way you can re-use your custom raster type if you want to load additional raster data with the same properties and functions.
To save your custom raster type, click on the General tab. At the bottom of this tab, you will see a Save As button. Click the Save As button, and save it in the location where you keep all your custom raster types.