OpenEXR Bitmap

Use

You can view OpenEXR Bitmap (.exr) files. You can also save files to this format.

The .exr format was developed by Industrial Light & Magic (ILM) for OpenEXR. OpenEXR is used by ILM on all motion pictures currently in production.

Supported

16-bit floating-point, 32-bit floating-point, and 32-bit integer pixels
Extensibility to include new compression codec and image types
High dynamic range image (HDRI) and color precision. Note that when you open a high dynamic range image (HDRI), resolution controls are displayed in the Information bar. These allow you to modify the image.
Multiple lossless image compression algorithms

Features

This format contains export options. You can use them to customize the way in which your file is saved.

Export Interface

Field	Functional Description
Compression Type	Selects the type of compression to apply when saving the file None: Saves the file using no compression Run-Length Encoding: Saves the file using a run length encoding compression. Run-length encoding (RLE) is a very simple form of data compression in which repeated data (that is, sequences in which the same data value occurs many consecutive times, or in a run) are stored as a single data value and how many times it occurs. zlib Single Scan Lines: Saves the file using a zlib compression performed one scan line at a time zlib 16 Block Scan Lines: Saves the file using a zlib compression performed in blocks of 16 scan lines. This option is most effective with images that do not have film grain applied. Piz-based Wavelet: Saves the file using a combined wavelet / Huffman compression. This form of compression is quite effective when dealing with grainy images, and will often surpass any of the other options under grainy conditions. Lossy 24-bit Float Compression: Saves the file using lossy compression. Lossy compression treats two vertices that are sufficiently close to each other as one, resulting in a change of image size and quality.
Line Order	Selects the order in which to perform the compression based on the first scan line Use Lowest Y Coordinate Scan Line: Begins the compression using the scan line with the lowest Y coordinate Use Highest Y Coordinate Scan Line: Begins the compression using the scan line with the highest Y coordinate

Field

Functional Description

Compression Type

Selects the type of compression to apply when saving the file

None: Saves the file using no compression
Run-Length Encoding: Saves the file using a run length encoding compression. Run-length encoding (RLE) is a very simple form of data compression in which repeated data (that is, sequences in which the same data value occurs many consecutive times, or in a run) are stored as a single data value and how many times it occurs.
zlib Single Scan Lines: Saves the file using a zlib compression performed one scan line at a time
zlib 16 Block Scan Lines: Saves the file using a zlib compression performed in blocks of 16 scan lines. This option is most effective with images that do not have film grain applied.
Piz-based Wavelet: Saves the file using a combined wavelet / Huffman compression. This form of compression is quite effective when dealing with grainy images, and will often surpass any of the other options under grainy conditions.
Lossy 24-bit Float Compression: Saves the file using lossy compression. Lossy compression treats two vertices that are sufficiently close to each other as one, resulting in a change of image size and quality.

Line Order

Selects the order in which to perform the compression based on the first scan line

Use Lowest Y Coordinate Scan Line: Begins the compression using the scan line with the lowest Y coordinate
Use Highest Y Coordinate Scan Line: Begins the compression using the scan line with the highest Y coordinate