Convert JPG to DAT

A legacy application, game, device, or Video CD authoring tool may require a file with a .dat extension instead of a JPG. Because DAT is not one standardized image format, the required conversion depends on the software or hardware that will read the result.

What the JPG format is

JPG, also called JPEG, is a compressed raster-image format used for photographs, scans, web images, and camera files. It stores pixels with lossy compression and commonly uses the .jpg or .jpeg extension.

Digital cameras, smartphones, scanners, Adobe Photoshop, GIMP, Windows Photos, macOS Preview, and web browsers commonly create or export JPG files. JPG is widely supported and relatively small, but repeated resaving can reduce detail and the format does not preserve transparency.

What the DAT format is

.dat means data, not a specific technical format. A DAT file can contain raw pixels, application records, game assets, database data, MPEG-1 video, or a program-specific binary structure. Its layout is defined by the application or device that created it.

DAT is useful only in the context of that specification: raw DAT can provide a predictable, uncompressed pixel layout; a Video CD uses MPEG-1 video stored in files such as AVSEQ01.DAT; and proprietary software may use DAT for indexed resources or metadata. Renaming photo.jpg to photo.dat changes the filename only and does not convert the contents. Files such as thumbnail.dat generated by photo managers are usually internal caches, not image files that can be created by a general converter.

How to convert a JPG to raw DAT

Use this method only when the receiving program documents a raw-pixel DAT format. Before exporting, obtain its required width, height, channel order, bit depth, byte order, row alignment, and header structure.

1. Install ImageMagick from its official distribution and keep the original JPG unchanged.
2. For 8-bit grayscale pixels, run magick input.jpg -colorspace Gray -depth 8 gray:output.dat.
3. For 8-bit RGB pixels, run magick input.jpg -alpha off -depth 8 rgb:output.dat.
4. For 8-bit RGBA pixels, run magick input.jpg -depth 8 rgba:output.dat.

These raw outputs contain no dimensions, color profile, channel description, or format header. The receiving software must already know those values. If it requires BGR order, a header, padding, a different bit depth, or a proprietary record structure, follow that specification instead of using a generic raw export.

How to create a Video CD-style DAT

A JPG cannot become a Video CD DAT while remaining a still image. It must first be encoded as MPEG-1 video, then processed by Video CD authoring software. A command such as the following creates a 10-second, video-only MPEG-1 stream at a common PAL frame size:

ffmpeg -loop 1 -i input.jpg -t 10 -vf scale=352:288,format=yuv420p -r 25 -c:v mpeg1video -b:v 1150k -f mpeg output.dat

For an NTSC workflow, use the target authoring tool's required settings, commonly 352×240 at approximately 29.97 frames per second. The command's output is an MPEG stream with a .dat extension; it is not necessarily a complete, compliant Video CD. Video CD authoring software must create the disc structure and may require compliant audio, GOP, sector, and multiplexing settings. For several JPGs, import them into a slideshow or authoring project, set each display duration, and let the authoring software encode the sequence.

How to handle application-specific DAT files

Use the target program's documented File → Import or File → Export function whenever available. Some DAT formats require metadata blocks, checksums, encryption, proprietary compression, or a companion index; ImageMagick and FFmpeg cannot generate those structures without the application's specification.

Online services such as CloudConvert and Zamzar are reasonable for nonconfidential images only when their conversion lists explicitly identify the required DAT subtype. A generic online “JPG to DAT” page may merely rename the file or produce data for an unrelated application. Do not upload private images without checking the service's retention and privacy terms.

Quality and compatibility limits

Converting a JPG cannot restore detail lost during JPEG compression. Decode the original JPG once and generate the required DAT from it instead of repeatedly exporting intermediate JPG files.

Raw DAT is usually much larger than JPG because it stores uncompressed pixels. An 8-bit grayscale image requires about width × height bytes, RGB requires about three times that amount, and RGBA requires about four times that amount, excluding headers or alignment bytes.

The extension alone cannot identify a DAT encoding. Confirm the target application's exact specification and test the result with that application or device; a DAT made for one system may be unreadable by every other system.