Image to Tiled Multiresolution OpenEXR Converter Overview

This is tool that can be used to convert a variety of image files to tiled multiresolution .exr files in OpenEXR format. The resulting tiled OpenEXR textures can be used in V-Ray for 3ds Max through the VRayHDRI texture, or directly in V-Ray for Maya and V-Ray Standalone.

Supported input image formats are:

  • V-Ray image file (*.vrimg)
  • Portable Network Graphics (*.png)
  • Windows bitmap (*.bmp)
  • Targa image file (*.tga)
  • Radiance HDR image (*.hdr)
  • Silicon Graphics (*.sgi, *.rgb, *.rgba)
  • JPEG image file (*.jpg, *.jpeg, *.jpe)
  • OpenEXR image file (*.exr)
  • Softimage PICT file (*.pic)
  • Tagged image file format (*.tif, *.tiff)
  • Photoshop (*.psd)


There are several methods for running the img2tiledexr converter:

  • The simplest way is to double-click the img2tiledexr.exe file from the V-Ray Standalone distribution that ships with your copy of V-Ray for Softimage. This will bring up the GUI main window of the program letting you to select all the options, browse the input file/directory and after that press the Convert button. You can optionally specify input directory, where all the converted files will be placed. If not specified all converted files will be written to the directories, they were found.
  • There are three methods for running the img2tiledexr from the command line:
    • If you type just

      > img2tiledexr

      on the command line, this is the same as double-clicking the file.

    • Converting a single image file to a single .exr file:

      > img2tiledexr <image_file><exr_file> [options]

      In this case, the <image_file> cannot contain wildcards. Note that the .exr extension is not added automatically to the output file name.

    • Converting multiple image files to multiple .exr files:

      > img2tiledexr <image_wildcard> [output_dir] [options]

      In this case, <image_wildcard> can contain the wild-card symbols '*' and '?'; the image files will automatically be converted to OpenEXR tiled multiresolution files with the .exr file extension. Optionally you can specify in <output_dir> the directory of the output files. If not specified, the output files will be written to the input directory.

      Caution! Under Linux and OS X parameters with wildcards must be enclosed with apostrophe symbols - 'image_wildcard'. Otherwise the command line shell will expand automatically the wildcard into file list, which will force the program to terminate.

In all cases, the original image files are not deleted.

Postfix "_tiled" will be added to the file name in case you use wildcards.

Note that many applications expect the colors in OpenEXR files to be in linear color space rather than sRGB/gamma 2.2 color space.. For this reason, img2tiledexr automatically converts the colors in the input image from sRGB to linear space for all image file formats except .hdr and .exr images. You can use the -linear option to control this conversion.


One or more of the following options may be specified:

-32bitStores the floating-point data in the .exr file as 32-bit floating point numbers. If this option is not specified, the data is stored as 16-bit floating point numbers.
-compression <method>Sets the compression type for the resulting .exr file. If not specified, ZIP compression is used. Currently supported values for <method> are: nonerlezipszippizpxr24
-tileSize <size>Set in <size> the dimension of a square tile. If not specified, the default tile size is 64x64.
-linear <mode>Specifies if the input image should be converted from sRGB to linear color space when saved into the tiled OpenEXR file. Possible values are: off (no conversion), on (convert colors from sRGB to linear space), auto (convert all images except .hdr and .exr files).
-subdirs When using wildcard, this option makes img2tiledexr to search the subdirectories of the specified one.
-help Print the help massage