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What's New in ENVI 5.2

Mark Alonzo

What's New in This Release

ENVI 5.2 includes the new and enhanced features listed below. See the following sections:

Sensors and Data Formats

ENVI reads and displays imagery from the following sensors and data formats:

  • AlSat-2A
  • Deimos-1
  • Gaofen-1
  • GRIB-1 and GRIB-2
  • Multi-page TIFF
  • NetCDF-4
  • Proba-V S10 TOC products, including NDVI
  • Proba-V S1 TOA and TOC products
  • SkySat-1 Image Frames
  • WorldView-3
  • Ziyuan-1-02C and -3A

ENVI plays videos files, including those from Skybox Imaging. The Full Motion Video player displays MISB metadata if the video file contains it. Export individual frames to the ENVI display for further analysis, or convert a video file to a time-enabled raster series. ENVI reads the following video formats in the Full Motion Video player:

  • Adobe Flash Video (.flv, .f4v)
  • Adobe Shockwave Flash (.swf)
  • Animated Graphics Interchange Format (.gif)
  • Apple Quicktime (.mov)
  • Audio Video Interleaved (.avi)
  • Google WebM Matroska (.webm)
  • Matroska Video (.mkv)
  • Motion JPEG (.mjpeg, .mjpg)
  • Motion JPEG2000 (.mj2)
  • MPEG-1 Part 2 (.mpeg, .mpg, .mp1, .m2v)
  • MPEG-2 Transport Stream (.ts)
  • MPEG-2 Part 2 (.mpeg, .mpg, .mp2, .mpg2, .mpeg2, .mpv, .m2v)
  • MPEG-4 Part 12 / 3GPP / 3GPP2 (.3gp, .3g2)
  • MPEG-4 Part 14 (.mp4, .mpg4, .mpeg4, .m4v, .h264)
  • Skybox (SkySat) video files

Image Processing

Spatiotemporal Analysis

You can build a series of images (also called a raster series) for spatiotemporal analysis, which provides the ability to understand and predict Earth surface processes or human activities over space and time. ENVI automatically reads raster "acquisition time" metadata from a wide variety of sensor data sources. Use the following tools:

  • Build Raster Series: Create a series file that references the file locations of images in your collection. Order the raster series sequentially according to acquisition time metadata.
  • Reproject Raster Series: Normalize a stack of rasters to a common spatial grid with automatic resampling and reprojection.
  • Series/Animation Manager: View and animate a spatiotemporal series with time slider and wheel controls. Also export a raster series to common video formats.
  • Write IDL scripts to perform all of these tasks; see the Programming section below.
  • Learn how to build and animate a series of Landsat images in the Time Series tutorial.

Spectral Indices

Use the Spectral Indices tool to compute various indices (one at a time), including vegetation, geology, man-made features, burned areas, and water:

  • It includes all of the existing vegetation indices from the Vegetation Index Calculator.
  • The following are new vegetation indices:
    • Difference Vegetation Index
    • Global Environmental Monitoring Index
    • Green Atmospherically Resistant Index
    • Green Difference Vegetation Index
    • Green Normalized Difference Vegetation Index
    • Green Ratio Vegetation Index
    • Green Vegetation Index
    • Infrared Percentage Vegetation Index
    • Leaf Area Index
    • Modified Chlorophyll Absorption Ratio Index
    • Modified Chlorophyll Absorption Ratio Index - Improved
    • Modified Non-Linear Index
    • Modified Simple Ratio
    • Modified Triangular Vegetation Index
    • Modified Triangular Vegetation Index - Improved
    • Non-Linear Index
    • Normalized Difference Water Index
    • Normalized Multi-band Drought Index
    • Optimized Soil Adjusted Vegetation Index
    • Red Green Ratio Index
    • Renormalized Difference Vegetation Index
    • Soil Adjusted Vegetation Index
    • Simple Ratio
    • Transformed Chlorophyll Absorption Reflectance Index
    • Transformed Difference Vegetation Index
    • Triangular Vegetation Index
    • Visible Atmospherically Resistant Index
    • WorldView Improved Vegetative Index (WV-VI)
  • The following are new indices for other features:
    • Burn Area Index
    • Clay Minerals Ratio
    • Ferrous Minerals Ratio
    • Iron Oxide Ratio
    • Normalized Burn Ratio
    • Normalized Burn Ratio Thermal 1
    • Normalized Difference Built-Up Index
    • Normalized Difference Snow Index
    • WorldView Built-Up Index
    • WorldView New Iron Index
    • WorldView Non-Homogenous Feature Difference
    • WorldView Soil Index
  • Use the ENVIQuerySpectralIndices API routine to determine which indices can be computed for a given image.
  • Write IDL scripts to compute spectral indices; see the Programming section below.
  • An EO-1 Hyperion Vegetation Indices tutorial shows how to pre-process Hyperion data and use vegetation indices to examine areas of unhealthy vegetation in a forest.
  • A Burn Indices tutorial shows how to create and compare spectral indices of burned areas from Landsat-8 imagery.

The NNDiffuse Pan Sharpening tool uses the nearest neighbor diffusion (NNDiffuse) pan sharpening algorithm to create a pan-sharpened raster from a low-resolution multispectral raster and a high-resolution panchromatic raster.

A hyperspectral analysis tutorial explains how to use Spectral Angle Mapper (SAM) classification and Spectral Feature Fitting (SFF) to compare image spectra to reference spectra.

The Scatter Plot tool has been updated for the new ENVI interface. Select bands from different rasters, create density slices, import/export ROIs, create a spectral profile, calculate mean spectra and class statistics, export plots to common formats, etc. The "dancing layers" functionality highlights pixels that correspond to the cursor location in the Image window.

The Raster Color Slice tool performance has improved; the histogram plots have tick marks and labels, the ability to zoom in/out, and a cursor crosshair that reports pixel values.

The Feature Counting tool has been completely redesigned:

  • Features are listed in a table view that provides colored text and the ability to sort features.
  • Symbols, labels, and counts can be turned on and off in the display.
  • New symbols have been added.
  • Geolocation parameters are automatically determined for features derived from a georeferenced image.
  • Features contain an optional Description field for capturing additional details.
  • A Grid option allows you to overlay grids on the top-most layer listed in the Layer Manager.
  • Save features to an ENVI Feature Counting file (.efc) and restore this type of file in a future ENVI session. You can also save features to shapefiles and geodatabase files.

Restoring ENVI Classic ROI files (.roi) maintains their original geometry without converting polygons to pixels.

The n-D Visualizer Export All function exports ROIs back to the ROI Tool.

Esri® Integration

The Layer Manager and Data Manager have right-click Refresh options to reload saved modifications to an Esri Layer file in a concurrent session of ArcMap™ software.

Create a new File Geodatabase in ENVI and write directly to it.

ENVI reads and writes to ArcGIS® 10.2 Enterprise SDE Geodatabases via .sde connection files.

ENVI's 32-bit application shortcuts for use with ArcGIS for Desktop software are located under the ENVI 5.2 > ENVI for ArcGIS® folder in the Windows Start menu.

The Remote Connection Manager has been enhanced as follows:

  • ENVI lists the same Enterprise SDE Geodatabase connections as ArcCatalog™ software's "Database Connections."
  • ENVI displays the same user interface dialogs as ArcGIS for Desktop software, for establishing Enterprise SDE Geodatabase connections.
  • For ArcGIS for Server connections, ENVI only lists the supported Image Services data assets on the server.

A Mouse Wheel Zoom Direction preference controls the direction of the mouse wheel, so you can match the direction that ArcMap software uses.

Send datasets to ArcMap software using the Data Manager, Layer Manager, and the File > Chip View to ArcMap menu option.

Save data to a new geodatabase that is compatible with the currently installed version of ArcGIS® software.

User Interface

Export the contents of a display view to a Geospatial PDF file. Chip the view at display resolution.

Export the contents of a display view to Google Earth.

Animate through bands of an image by selecting Display > Band Animation. Or, right-click on an image layer in the Layer Manager and select Band Animation.

A Preview option is available for NNDiffuse Pan Sharpening, Classification Aggregation, and Spectral Indices that allows you to dynamically preview processing results for the area displayed in the Image window before processing the full image.

The Layer Manager and the Toolbox panels can be widened by clicking and dragging on the side of the panel.

The snail trail in the Overview window can be saved to a file.

Create placemarks of geographic locations to quickly find different places in the Image window.

The vector and annotation buttons have been merged into two drop-down lists on the toolbar.

The Preferences dialog has a new search field. Both 64-bit and 32-bit application modes share the same preferences.

The Undo and Redo buttons have been removed from the toolbar; these functions are still available under the Edit menu and by using Ctrl-Z and Ctrl-Y keyboard shortcuts.

The Select HDF5 Datasets dialog was renamed to the Dataset Browser; use this dialog to build raster files from NetCDF-4 and HDF5 datasets.

The Favorites section of the Toolbox has more options for managing favorite tools.

You can select a quick stretch type while defining a spatial subset.

You can right-click on an image in the Layer Manager and select Quick Stats to view image statistics.

Highlight a vector record in the Attribute Viewer table, then click Go To in the menu bar to center the image window over its location and to highlight the selected vector.

Use the File > Save As menu option to save images to ASCII, ArcView Raster, CADRG, CIB, ER Mapper, ERDAS IMAGINE, JPEG2000, and PCI formats. These save options were previously available through the Toolbox.


A new ENVI API Programming Guide in the ENVI Help explains how to write IDL scripts to extend ENVI functionality.

Use these new routines to write scripts that perform image-processing tasks. You can also publish these tasks to client applications using ENVI Services Engine.



ENVIAutoChangeThresholdClassificationTask Perform image change detection using automatic thresholding.
ENVIBuildBandStackTask Combine bands from different images into a single image. Use a combination of this routine and ENVIRegridRasterTask to create a layer stack.
ENVIBuildRasterSeriesTask Build a raster series file for spatiotemporal analysis.
ENVIBuildTimeSeriesTask Build a raster series file, ordered by acquisition time, for spatiotemporal analysis.
ENVIChangeThresholdClassificationTask Perform image change detection using manual thresholding.
ENVIClassificationAggregationTask Clean up classification results using an aggregation operation.
ENVIClassificationSmoothingTask Clean up classification results using a smoothing operation.
ENVIClassificationToShapefileTask Export one or more classes to a single shapefile.
ENVIColorSliceClassificationTask Create a classification raster by thresholding select data ranges and colors.
ENVIDarkSubtractionCorrectionTask Perform dark subtraction atmospheric correction.
NVIDimensionsResampleRasterTask Resample an image to different spatial dimensions.
ENVIEqualizationStretchRasterTask Apply a histogram equalization stretch to an image.
ENVIForwardICATransformTask Perform a forward independent component analysis (ICA) transform.
ENVIForwardMNFTransformTask Perform a forward minimum noise fraction (MNF) transform.
ENVIForwardPCATransformTask Perform a forward principal components analysis (PCA) transform.
ENVIFXSegmentationTask Perform a Feature Extraction segment-only workflow.
ENVIGaussianStretchRasterTask Apply a Gaussian stretch to an image.
ENVIGramSchmidtPanSharpeningTask Perform Gram-Schmidt pan sharpening.
ENVIImageBandDifferenceTask Perform a difference analysis on a specific band in two images.
ENVIImageIntersectionTask Compute the overlapping area of two images.
ENVIImageThresholdToROITask Define one or more ROIs using at least one threshold.
ENVIISODATAClassificationTask Perform unsupervised classification using the ISODATA method.
ENVILinearPercentStretchRasterTask Apply a linear stretch to an image, using a specified percentage value.
  • Apply a linear range stretch to an image.
  • ENVILogStretchRasterTask Apply a logarithmic stretch to an image.
    ENVIMahalanobisDistanceClassificationTask Perform Mahalanobis Distance supervised classification.
    ENVIMappingResampleRasterTask Resample an image to different dimensions using column and row mapping.
    ENVIMaximumLikelihoodClassificationTask Perform Maximum Likelihood supervised classification.
    ENVIMinimumDistanceClassificationTask Perform Minimum Distance supervised classification.
    ENVINNDiffusePanSharpeningTask Perform NNDiffuse pan sharpening.
    ENVIOptimizedLinearStretchRasterTask Apply an optimized linear stretch to an image.
    ENVIPCPanSharpeningTask Perform PC pan sharpening.
    ENVIPercentThresholdClassificationTask Segment an image into anomalous and non-anomalous regions.
    ENVIPixelScaleResampleRasterTask Resample an image to different dimensions by multiplying the pixel size by a scale factor.
    ENVIQuerySpectralIndicesTask Determine which spectral indices are available for a given image.
    ENVIRadiometricNormalizationTask Create an image from two rasters that minimizes their differences caused by inconsistent image acquisition conditions.
    ENVIRasterStatisticsTask Calculate basic image statistics.
    ENVIRasterViewshedTask Calculate a viewshed from a DEM.
    ENVIRegridRasterSeriesByIndexTask Reproject a raster series to a spatial grid, using the grid parameters of a selected raster index.
    ENVIRegridRasterSeriesByIntersectionTask Reproject a raster series to a spatial grid, using the geometric intersection of all of the rasters.
  • Reproject a raster series to a spatial grid, using the geometric union of all of the rasters.
  • ENVIRegridRasterTask
  • Reproject an image to a spatial grid.
  • ENVIROIToClassificationTask Create a classification image from ROIs.

    Apply a root stretch to an image.

    ENVIRXAnomalyDetectionTask Perform Reed-Xiaoli (RX) anomaly detection.
    ENVISpectralAngleMapperClassificationTask Perform Spectral Angle Mapper (SAM) supervised classification.
    ENVISpectralIndexTask Create a spectral index image from one pre-defined index.
    ENVISpectralIndicesTask Create a multi-band image, where each band is a different spectral index.
    ENVIThematicChangeTask Input two classification images of the same scene taken at different times and identify differences between them.
    ENVITrainingClassificationStatisticsTask Compute statistics from classification training regions.
    ENVIVectorAttributeToROIsTask Create ROIs from geometry records in a vector.
    ENVIVectorRecordsToROITask Create one ROI from all geometry records in a vector.
    ENVIVegetationSuppressionTask Remove the vegetation spectral signature from multispectral and hyperspectral imagery.

    Export frames from a video file to a raster series.

    Use the ENVIGridDefinition routine to create a spatial grid definition, which is used to georeference rasters and vectors to a common coordinate system. ENVIGridDefinition is only a definition, not a spatial reference or raster. It can be used as an input to ENVISpatialGridRaster or to define the grid parameters for an empty raster.

    Use the following routines to create images with different stretches applied:

    • ENVIEqualizationStretchRaster
    • ENVIGaussianStretchRaster
    • ENVILinearPercentStretchRaster
    • ENVILinearRangeStretchRaster
    • ENVILogStretchRaster
    • ENVIOptimizedLinearStretchRaster
    • ENVIRootStretchRaster

    Use the ENVIMetaspectralRaster routine to create an image that consists of bands from different images. Or, use this routine in combination with ENVISpatialGridRaster to create a georeferenced layer stack.

    Use the ENVINNDiffusePanSharpeningRaster routine to create nearest neighbor diffusion (NNDiffuse) pan sharpened rasters from a low-resolution raster and a high-resolution panchromatic raster.

    Use the ENVIPreferences and ENVIPreferenceItem routines to manage preference settings.

    Use the ENVIRasterSeries routine to build a series of images for spatiotemporal analysis. Then use the ENVIRasterSeriesLayer routine to display the raster series.

    Use the ENVIRasterStatistics routine to get statistics for all bands of an image.

    Use the ENVIResampleRaster routine to resample images.

    Use the ENVISpatialGridRaster routine to project an image to a standard spatial reference.

    Use theENVISpectralIndexRaster routine to create new rasters based on common spectral indices.

    The ENVIView routine has a new ChipToVideo method that saves an animation from spatiotemporal analysis to a variety of video file formats.

    The ENVIRaster::Subset method has been deprecated. Use ENVISubsetRaster for spatial and spectral subsetting.

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