Supported Graphics Formats¶
This is the list of image file formats supported internally by Blender:
|JPEG 2000||8, 12, 16bit||✓||✗||✗||
|Cineon & DPX||8, 10, 12, 16bit||✓||✗||✗||
|OpenEXR||float 16, 32bit||✓||✓||✓||
If you are not interested in technical details, a good rule of thumb for selecting output formats for your project is:
- Use OpenEXR
- if you intend to do compositing or color grading on these images.
- Use PNG
- if you intend on-screen output or encoding into multiple video formats.
- Use JPEG
- for on-screen output where file size is a concern and quality loss is acceptable.
All these formats support compression which can be important when rendering out animations.
Bit depths for image formats represent the following numbers of tonal levels per channel:
- Relative Path
- Sets the file path to be relative to the currently open blend-file.
- Detect Sequences
- Automatically detects image sequences in the selected images (based on the file name). Disable this when you do want to get single images that are part of a sequence.
Opening an Image Sequence¶
The filename of the images must contain a digit, indicating the frame. The sequence could be opened by the selection of the images and by the confirmation with the Open Image button or Return.
- File Format
- Choose what format to save the image as.
- Color Mode
Choose the color format to save the image (or video) to. Note that RGBA is not available for all image formats, check the list above for details.
BW, RGB, RGBA
- Color Depth
Image file formats support a varying number of bits per pixel. This affects the color quality and file size. Commonly used depths:
- 8 bit (256 levels)
- Most common for on-screen graphics and video.
- 10, 12, 16 bit
- Used for some formats focusing on photography and digital films (such as DPX and JPEG 2000).
- 16 bit half float
- Since full 32bit float is often more than enough precision, half float can save drive space while still providing a high dynamic range.
- 32 bit float
- Highest quality color depth.
Internally Blender’s image system supports either:
- 8 bit per channel (4 x 8 bits).
- 32 bit float per channel (4 x 32 bits) – using 4x as much memory.
Images higher than 8 bits per channel will be converted into a float on loading into Blender.
- Used to reduce the size of the image file. How this is done may vary depending on the file format and settings used.
- Similar to Compression but is used for JPEG based file formats. The quality is a percentage, 0% being the maximum amount of compression and 100% is no compression.
- Save As Render
- Applies color transform to the saved image.
- The Copy checkbox will define if the data-block will reference the newly created file or the reference will be unchanged, maintaining it with the original one.
Cineon & DPX¶
Cineon is Kodak’s standard for film scanning, 10 bits/channel and logarithmic. DPX has been derived from Cineon as the ANSI/SMPTE industry standard. DPX supports 16 bits color/channel, linear as well as logarithmic. DPX is currently a widely adopted standard used in the film hardware/software industry.
DPX as well as Cineon only stores and converts the «visible» color range of values between 0.0 and 1.0 (as a result of rendering or composite).
ILM’s OpenEXR has become a software industry standard for HDR image files, especially because of its flexible and expandable structure.
An OpenEXR file can store multiple layers and passes. This means OpenEXR images can be loaded into a compositor keeping render layers, passes intact.
Available options for OpenEXR render output are:
- Color Depth
Saves images in a custom 16 bits per channel floating point format. This reduces the actual «bit depth» to 10 bits, with a 5 bits power value and 1 bit sign.
Float (Half), Float (Full)
- Lossless wavelet compression. Compresses images with grain well.
- Standard lossless compression using Zlib.
- Run-length encoded, lossless, works well when scanlines have same values.
- Lossy algorithm from Pixar, converting 32 bits floats to 24 bits floats.
- Z Buffer
- Save the depth information. In Blender, this now is written in floats too, denoting the exact distance from the camera in «Blender unit» values.
- On rendering animations (or single frames via command line), Blender saves the same image also as a JPEG, for quick preview or download.
Radiance is a suite of tools for lighting simulation. Since Radiance had the first (and for a long time the only) HDR image format, this format is supported by many other software packages.
.hdr files store colors still in 8 bits per component, but with an additional
(shared) 8 bits exponent value, making it 32 bits per pixel.