Working with Imagery in ArcGIS 10 Jennifer Kuntz
Overview of Presentation Imagery Overview Display Looks Great, Draws Quickly - Image Analysis Window - Acceleration Process - Image Analysis Window (part 2) - Data Extraction Manage Serve
What is imagery in ArcGIS? Imagery is raster data - Aerial photography - Satellite imagery - Thermal imagery - Digital elevation models - Scanned maps - Land classification - Surfaces created from analysis
Adding Imagery and Raster Data File on disk Geodatabase Mosaic dataset Stored like a raster catalog With more capabilities Metadata is stored in attributes User experience like a raster dataset
Adding Imagery and Raster Data ArcGIS Online Map Service Image Service WCS / WMS Service
Raster Properties Data source - Type of file and location Raster information - Information about the pixels Extent - Top, bottom, left and right extents Spatial reference - Coordinate system information Statistics - Min, max, mean, and standard deviation (per band)
Raster Datasets - Properties Pyramids - Reduced resolution copies of the source Factor of 2 - Improve display performance - Support three resample methods - Can be compressed (new) set in GeoProcessing environment Nearest neighbor Bilinear interpolation Cubic convolution Statistics - Enhance visual display Unstretched: Min: 24 Max: 241 Stretched: Min: 0 Max: 255 Build Pyramids and Statistics tool (new)
Display
Displaying Raster Data Renderers - Display your data with a renderer that makes your data look good Image Analysis window - Common capabilities in one easy to access location
Stretched renderer Often used for elevation, satellite and aerial imagery Default: when raster has more than 25 unique values - Stretches values along a color ramp
Stretched renderer NEW at ArcGIS 10 Percent clip stretch Advanced labeling
RGB renderer Often used for satellite imagery and aerial photos Default: Raster has 3 or more bands - Displays each band through a different color (Red, Green, and Blue)
Unique Values renderer Often used for land use and scanned maps Default: Raster has fewer than 25 unique values - Uses random colors for individual values
Unique Values renderer NEW at ArcGIS 10 Create a custom CLR file
Colormap renderer Often used for land use and soil maps for consistency Default: Colormap is present - Uses pre-chosen colors for individual values 1 = = 255, 255, 50 2 = = 0, 0, 175 3 = = 255, 175, 20 4 = = 135, 90, 0 5 = = 120, 215, 0 6 = = 0, 100, 15 7 = = 100, 220, 255
Classified renderer Often used for grouping data values Not a default renderer; can be used for single band data Places ranges of pixels into separate categories
Image Analysis window Many rendering and processing tools to make your imagery work easier and faster You are able to change the following display parameters: - effects tools - symbology tools (gamma level, DRA, stretch, etc) - choose the resampling method - accelerate raster
Raster Display
Processing and Analyzing
Processing raster data in ArcGIS Combining bands Clipping Mosaicking Pansharpening Orthorectifying
Combining Bands Combine many images into a multi-band raster Input bands can be from a single or multiple band raster dataset Composite with geoprocessing tool or Image Analysis window Composite Bands
Clipping Clip a portion of raster to fit your study area Clip with geoprocessing tools or with Export Data dialog window Clip on-the-fly with Image Analysis window - Also able to mask (instead of clip) Clip
Mosaicking Combine two more adjacent and overlapping rasters together Many mosaic geoprocessing tools: - Workspace to raster dataset - Raster catalog to raster dataset Mosaicking on-the-fly - Mosaic button on the Image Analysis window - Mosaic dataset (virtual mosaic)
Pansharpening Fuse a low resolution RGB image with a high resolution panchromatic image - Output is a high resolution color image Geoprocessing tool, raster symbology tab, or Image Analysis window
Orthorectify Display an image with more accuracy - Requires an image with sensor model and an elevation source Geoprocessing tool, raster display tab, or Image Analysis window
Image Analysis window Colormap to RGB Pan-sharpening NDVI Difference Orthorectify Clip Mask Composite bands Export data Shaded relief Mosaic Filter
Image Classification Spatial Analyst Extension Extract classes from multiband raster imagery Supervised or unsupervised Image Classification toolbar
Raster Analysis
Manage
Imagery Management Challenges Many sources High resolution and large volume Requirements: - Store efficiently - Easy to search - Fast to process - Accessible
ArcGIS 10 Image Management Recommendations Manage individual images using raster datasets Manage image collections using new mosaic datasets
Licensing Mosaic Dataset - View: ArcView license - Create / edit: ArcInfo/ArcEditor license - Serve: ArcGIS server + Image extension license Raster Dataset - View: ArcView license - Create / edit: ArcInfo/ArcEditor license - Serve: ArcGIS server
Raster Datasets Recommendations Use it as is - Especially for compressed formats Better performance - Convert to tiled TIFF using the CopyRaster tool - JPEG compressed TIFF if lossy compression is allowed - File Geodatabase raster dataset is also a comparable format
Managing Imagery Collections Solution in 9.3 is raster catalog - image service definition Solution in 10 is mosaic dataset
Raster Catalogs A data model for managing a collection of images in 9.3 - Stores footprints and rasters in a table - Managed/unmanaged Uses - Catalog images and maintain overlaps - Search based on attributes and location - Access selected members - Display footprint/pixel view Limitations - Do not support sensor data and metadata - No overview - Can t be served by ArcGIS server
Mosaic Datasets - New Geodatabase Data Model Manage and serve collection of images - Supported in SDE/FGDB/PGDB - Does not load source pixels into geodatabase, instead references imagery Manage data with an internal raster catalog Mosaic Dataset Displays like a raster dataset On-the-fly image processing
Mosaic Dataset rendering Footprint view - View the minimum bounding rectangle for each raster
Mosaic Dataset rendering Rendering pixels similar to a raster dataset - Level of detail like scale dependency - Overviews like pyramids 1 : 25 000 1 : 100 000
Mosaic Dataset Storage Catalog Table OID Shape Raster Name LowPS HighPS MinPS MaxPS Category 1 Polygon <Raster> P01.met 10 30 0 90 Primary 2 Polygon <Raster> P02.met 10 30 0 90 Primary 5 Polygon <Raster> filename1.tif 90 90 90 270 Overviews A special raster catalog - Shape field stores the footprints - Raster field stores raster dataset information Function raster datasets - Contains functions and input of the functions - Defined by raster type and populated when rasters are added MinPS and MaxPS define the visible ranges of the rasters
Mosaic Dataset Mosaic Rules Closest to the center Control which raster/pixels to display Mosaic method to sort the rasters - Closest to center (default) - By attribute - Closest to nadir - North west - Seamline Mosaic operator to resolve the overlaps - First/Min/Max/Mean/Blend By attribute: cloud cover
Mosaic dataset: on-the-fly processing Imagery processed as it is accessed Can create multiple products from one source Processing - Image enhancement - Combine bands - Color correction - Orthorectification - Pan-sharpen - Shaded relief, hillshade Define processing functions - On each raster dataset - On a mosaic dataset
Mosaic Datasets - Advantages Processing Time Reduces processing Scalable Catalog large image collections Storage Eliminates redundancy Seamless Display at all scales Sensor support Support multiple sensors Metadata Maintains valuable information Preserves information Overlapping Imagery Disparate Datasets Manages large NoData areas Maintenance Streamlines image updates Image Quality Reduces resampling
Data Management Recommendations Use your existing data model if they continue to meet your existing application requirements Use the mosaic dataset for new applications Migrate to the mosaic dataset to take advantages of its new features
Mosaic Dataset Usage A composite layer of - Boundary/Footprint/Image Use as a catalog - Search images - View metadata - Add selected images to Map - Time aware Use as a raster dataset - Display like a raster layer - Export a raster dataset - Use as an input to geoprocessing tool Serve as an image service
Using Mosaic Datasets
Build a Mosaic Dataset In ArcCatalog Mosaic dataset toolset Automate with model and python Typical workflow - Create a mosaic dataset - Add rasters - Calculate cell size range - Build boundary - Build overviews (optional) - Edit properties (optional)
Build a Mosaic Dataset - Create Create table schema and define pixel properties Spatial reference (required) - Used in footprints and overviews - Define a proper one - Datum consideration Number of bands - Taken from the first added raster Pixel type - Taken from the first added raster
Build a Mosaic Dataset Add Rasters Use Add Rasters to Mosaic Dataset tool Choose a raster type - Define the format to crawl - Metadata to read and fields to create - Processes to apply Support many raster types - Raster Dataset/NITF/CADRG/etc. - QB/IKONOS/GeoEYE/WorldView/etc - Web Services - Table/Image Service Definition
Build a Mosaic Dataset Overviews Resampled rasters - Multiple levels - Multiple tiles for each level Seamless image display Overview: 180m (range: 180-1800) Overviews: 60m (range:60-180) PS=100 Sources: 20m (range: 0-20)
Build a Mosaic Dataset Overviews (Cont ) OID Shape Raster Name LowPS HighPS MinPS MaxPS Category 1 Polygon <Raster> P01.met 10 30 0 90 Primary 2 Polygon <Raster> P02.met 10 30 0 90 Primary 3 Polygon <Raster> filename1.tif 90 90 90 900 Overviews 4 Polygon <Raster> filename2.tif 90 90 90 900 Overviews Build Overviews tool - Generate overview images Define Overviews tool - Redefine the default parameters Optionally add an external raster as overview Default overview parameters: TIFF format with JPEG Size is 5120x5120 Factor of 3 Overview location
Building a Mosaic Dataset Managing Background Footprint - Build Footprint tool - Edit using Editor - Import using Import Mosaic Dataset Geometry tool Use footprint Define NoData - Set NoData based on a value - Set NoData based on a range Use NoData
Building a Mosaic Dataset Update Add new rasters - Use Add Raster tool - Use Synchronize Mosaic Dataset tool Remove Rasters - Use Remove Rasters from Mosaic Dataset tool Sources rasters are changed - Changes in geometric/metadata/etc. - Update with Synchronize Mosaic Dataset tool
Mosaic Dataset Advanced Mosaicking Color correction - Balance to a color surface - Balance to an existing target - Support excluded area - Color Correction window Before Seamline - Build Seamline tool - Modify seamline using Editor - Import seamline feature class After
Mosaic Dataset Editing Raster Functions Process image on-the-fly - Image enhancement - Orthorectification, Pansharpen - Shaded relief, hillshade, etc Add at mosaic dataset level Add at raster level - Apply to the raster
Referenced Mosaic Dataset References an external mosaic dataset or raster catalog - Supported in GDB and file (.amd) - Catalog table is not editable Boundary = My County Created by specifying - Definition query - Area of interest Where Sensor = Landsat and Cloud <10% Add NDVI processing Provides multiple views of the source mosaic dataset Prevents editing of the source mosaic dataset
Image Management Patterns Create mosaic datasets with data of similar type Elevation Ortho images of same date Imagery with similar sensor, number of bands, and bit depth QuickBird/IKONOS Landsat 5 or 7 Create referenced mosaic datasets to publish Mosaic Dataset to manage data Reference Mosaic Dataset to publish
Build Mosaic Datasets
Serve
Main ways to serve imagery Image service - Image or raster data made available by a server to a client application Map service - Published map document containing an image layer Other - Globe service, mobile service, geodata service
Image Service versus Map Service Image service Serves raster data directly Image service layer properties can be altered by client Compression Rendering Band combinations Can be saved as a layer and used as a data source Map service Serves a map document containing raster or vector data Client views map service as it was designed Client cannot change layer properties Can build cache
What can you do with an image service? Use it as an image (visual analysis) Use it as raster data (pixel analysis) Access it as a catalog (mosaic dataset)
Image service source data Data sources - Raster datasets - Mosaic datasets new - Requires ArcGIS Server Image Extension - Raster or mosaic layers - To control rendering - Preset some layer properties - Predefined query
Publishing an image service Same process as publishing any service with ArcGIS Server - via ArcCatalog - via Server Manager Properties unique to image services - Capabilities - Parameters Some capabilities are specific to the data
Image Service Capabilities Limits what operations users can do with your Web service Image Metadata Catalog Download Pixels Allows the image to be displayed (Absorbed the Mosaic operation in 9.3x) Allows the client to see metadata for the image service and for each raster in a mosaic dataset Allows the client to open the table of a mosaic dataset when it is served Allows rasters to be downloaded when serving a mosaic dataset Allows the API developer to access the pixel blocks of the individual rasters in a mosaic dataset
Image Service Parameters Control the image data Image new, Catalog new, Download new, and Output Parameters depend on the input for the image service Some can be altered by the server administrator Server administrator cannot exceed limitations for some of the parameters - Such as: allowed mosaic methods, the maximum number of rasters per mosaic
Image Service Parameters: Image Affect the image that users connected to the image service will see RD MD Layers Max image size per request Default resampling method Compression methods and quality Max # of rasters per mosaic Allowed mosaic methods
How can you access an image service? ArcGIS Desktop ArcGIS Explorer Web APIs (Silverlight, Flex, JavaScript) ArcGIS.com REST, SOAP WMS, WCS, KML 3rd Party Applications
Serving and Accessing Image Services
Resources
Want to Learn More? Video.esri.com - Using Imagery and Raster Data in ArcGIS - What's New in Imagery and Raster at ArcGIS 10 Training.esri.com - Recorded Training Seminars - Visualizing and Analyzing Imagery with ArcGIS 10 - Managing Imagery with ArcGIS 10 - Instructor-Led Training - Managing Imagery Using ArcGIS
Resources Resources.esri.com - Blog (RSS feed) - Samples - Videos - Forums - More