What is the MPO file format?
.mpo files were created by the Camera & Imaging Products Association (CIPA) for storing pictures taken with cameras equipped with a multiple stereoscopic lens system, such as the Fujifilm FinePix Real 3D series. An .mpo file contains two or more JPEG images concatenated into a single 3D-capable container, and each embedded image can also carry its own Exif metadata.
Internally, .mpo begins with a standard JPEG SOI marker (FF D8 FF), so it is a valid JPEG at byte offset 0. What distinguishes it is an APP2 segment containing the MPF tag - the Multi-Picture Format index defined in CIPA standard DC-007 - which records the byte offset and size of every additional JPEG frame appended after the first.
.mpo files are used for viewing images on devices that support 3D technology, usually on 3D TVs. Images stored as .mpo can be converted to an anaglyph image (a stereoscopic 3D composite viewed with colour-filter glasses) using stereoscopic image processing software such as StereoPhoto Maker.
.mpowas initially designed to store only two images, but the DC-007 specification now allows a single file to hold an unlimited number of.jpgframes. Still, most.mpofiles hold just two images: a left-eye and right-eye stereo pair..mpoimages are also produced and used by the Nintendo 3DS game console for its autostereoscopic display.- An
.mpofile opened in any standard image viewer will show only a single image, usually the one on the left side. - Because
.mpois a valid JPEG at offset 0, renaming the file to.jpglets most software open at least the first embedded image. A related stereo JPEG alternative is the .JPS format.
Security & safety
RISK: LOWAn MPO is passive image data (just JPEGs in a container) and contains no executable code, so opening one is safe. The only practical issues are non-malware: many apps only read the first image (you may not realize a second frame exists), and EXIF metadata (camera, date, sometimes GPS) travels with the file - strip it before sharing if privacy matters. As always, distrust anything calling itself an MPO that is actually an .exe.
Format details
in a nutshellFULL NAMEMulti-Picture Object (CIPA Multi-Picture Format)
DEVELOPERCIPA (Camera & Imaging Products Association)since 2009 (CIPA DC-007 Multi-Picture Format)
CATEGORYRaster Image Files
MIME TYPEimage/mpo
TYPEContainer of multiple JPEG images in one file (binary)
STANDARDOpen · royalty-free
MAGIC BYTES · FILE SIGNATURE
OFFSET
00010203
HEX
FFD8FFE1
ASCII
····
An MPO begins with a normal JPEG SOI marker (FF D8 FF ...) - it IS a JPEG file at offset 0. What makes it MPO is an APP2 segment containing the "MPF\0" ("Multi-Picture Format") tag, whose index points to a second (and further) JPEG image concatenated after the first. So an MPO is two-or-more JPEGs in one file plus an MP index; many tools see only the first JPEG.
Programs that open MPO files
Windows3 apps
StereoPhoto Maker
Free Open the MPO to view in 3D (anaglyph/side-by-side), split into L/R JPEGs, or batch-convert MPO to JPG. Actively updated (v6.33, Sep 2025). 
Adobe Photoshop
Paid Opens MPO (shows the first/left image); use to edit and Save As JPG. Subscription. 
IrfanView
Free Opens MPO and shows the first image; can extract frames and batch-convert to JPG/PNG. 
macOS2 apps
Apple Preview / Photos
Built-in Double-click to open the MPO; Preview displays the contained image(s). Export to JPEG via File > Export. 
Linux1 app
GIMP
Open-source Opens MPO as a JPEG (first image); File > Export As to JPG/PNG. For the 3D pair, use a dedicated tool.
Web1 app
Rename to .jpg (no tool)
Free Copy the file and rename .mpo to .jpg - any browser/viewer then shows the first image. Quickest way to just see the photo. Technical details
deep spec| Format type | Container of two or more concatenated JPEG images in one binary file |
| Magic bytes (hex) | FF D8 FF E1 - standard JPEG SOI + APP2 length bytes; MPO identity is confirmed by an APP2 payload beginning with the four-byte MPF signature |
| MIME type | image/mpo |
| Governing standard | CIPA DC-007 (Multi-Picture Format) |
| Key internal marker | APP2 segment carrying an MP index table that records each frame's image type, byte offset from JPEG SOI, and byte size |
| Typical image count | 2 (left-eye and right-eye stereo pair) |
| Maximum image count | Unlimited per CIPA DC-007 specification |
| Per-image format | Each frame is a self-contained, DCT-compressed JPEG image |
| Per-image metadata | Each embedded JPEG frame carries its own independent Exif segment |
| MP Entry attributes | Classify each frame as Baseline MP Primary or Dependent child image, with stored offset and size |
| Backward compatibility | File is a valid JPEG at byte offset 0; tools without MPO support silently display only the first (primary) image |
| Primary capture hardware | Dual-lens stereo cameras (Fujifilm FinePix Real 3D W1, W3) and Nintendo 3DS camera system |
| 3D rendering methods | Anaglyph (colour-filter glasses), side-by-side, top-and-bottom, and autostereoscopic display |
| Color encoding | sRGB, identical to standard JPEG; each embedded frame is an independent full-color image |
| Released | 2009 (CIPA DC-007 Multi-Picture Format) |
| Open standard | Yes · royalty-free |
| Specification | www.cipa.jp |
MPO conversions
Possible
.MPO .GIFGUIDE
Yes, MPO can be converted to an animated GIF - split the stereo frames in StereoPhoto Maker (free), then use…
How to convert
.MPO .JPEGGUIDE
Yes - the fastest way is to rename a copy of the file from .mpo to .jpg, which gives you the first (left-eye)…
How to convert
.MPO .JPGGUIDE
Yes - the quickest way is to rename a copy of the file from .mpo to .jpg, which gives you the first image…
How to convert
.MPO .PNGGUIDE
Yes, MPO can be converted to PNG -- IrfanView on Windows is the fastest way.
How to convert
.MPO .JPSGUIDE
Yes - StereoPhoto Maker (free, Windows) converts MPO to JPS in a few clicks.
How to convert
.MPO .PSDGUIDE
Yes -- open the MPO in Adobe Photoshop and use File > Save As to save it as a PSD.
How to convert
Community Q&A
asked by usersNo questions yet - be the first to ask about MPO files.
Frequently asked questions
How do I open an MPO file?
It's a JPEG-based 3D image. On Mac, Preview/Photos open it directly. On Windows, use free StereoPhoto Maker (for 3D) or IrfanView. Quickest of all: copy the file and rename .mpo to .jpg - any viewer then shows the first image.
How do I convert MPO to JPG?
Use StereoPhoto Maker or IrfanView to export the contained image(s) to JPG (both support batch). Or simply rename a copy of the .mpo to .jpg to extract the first frame, since an MPO already starts as a JPEG.
Why does my MPO file only show one image?
Most viewers read only the first JPEG in the MPO and ignore the second (right-eye) frame. Open it in StereoPhoto Maker to access and split out both images.
What creates MPO files?
3D cameras and devices: the Nintendo 3DS camera, Fujifilm FinePix Real 3D, some Panasonic/Sony 3D cameras, and early 3D phones (LG Optimus 3D, HTC EVO 3D). They store a left/right stereo pair as one MPO.
How do I see the 3D effect from an MPO?
Open it in StereoPhoto Maker and choose an output mode - red/cyan anaglyph (for cheap 3D glasses), side-by-side, or interlaced for a 3D display. It aligns the pair automatically.
Is MPO still used today?
Rarely for new photos - the 3D-camera/3D-TV wave faded after ~2013. You mostly meet MPO as legacy files from old 3D devices, which people now convert to plain JPG.
References
1CIPA DC-007 - Multi-Picture Format (MPO) specificationwww.cipa.jp
2StereoPhoto Maker - free MPO viewer/converter (official)stereo.jpn.org
