VOB to PPM Converter

How to Convert VOB to PPM Online

1. Upload Your VOB File: Drag and drop or click "Add Files" to select VOB files — typically from a DVD's VIDEO_TS folder. Batch is supported, so you can drop in multiple VTS_01_1.VOB, VTS_01_2.VOB segments and capture frames from each.
2. Pick the Frame Selection Mode: Default is Specific Frame — enter a Time in Seconds (e.g., 12.5 or 2.100 for 2 seconds + 100 ms). Switch to Multiple Screenshots to grab frames on a schedule (every 1/10 second up to every 10 seconds). Each output frame becomes one PPM file.
3. Set Resolution and Bit Depth (Optional): Under Image resolution, keep original, choose a Preset Resolution (4320p / 2160p / 1440p / 1080p / 768p / 720p / 480p / 360p / 240p / 144p), enter a Resolution Percentage, or set custom Width × Height. Under Bit Depth pick 8-bit (Recommended), 16-bit (High Precision), or 1-bit (Black & White).
4. Convert and Download: Click Convert. Frames extract on our servers — no sign-up, no watermark, no email required. Download individual PPM files or grab a ZIP for batch jobs.

Why Convert VOB to PPM?

VOB (Video Object) is the container DVDs use inside VIDEO_TS — a strict subset of the MPEG program stream carrying MPEG-2 video, AC-3/PCM/MP2/DTS audio, and subtitles, with each file capped at 1 GiB so older filesystems can read it. PPM (Portable Pixmap, magic number P6) is a Netpbm format whose entire spec fits on a single page: ASCII header, width, height, maxval, then raw RGB triplets. There's no compression, no color profile, no metadata — exactly what scientific imaging, computer-vision pipelines, and homework graders want from a video frame. Common reasons to convert:

• Computer-vision and ML pipelines — OpenCV, scikit-image, ImageMagick, GIMP, and almost every academic image-processing library read PPM natively because the format has no decoder ambiguity. Extracting frames as PPM gives you bit-exact pixels for OpenCV's cv2.imread, NumPy's imageio.imread, or MATLAB's imread.
• Image-processing coursework — Many university graphics courses (CS 4731, COS 350, similar) require students to write loaders for the raw P6 format. Converting a DVD frame to PPM gives you a real-world test image you can hand-parse byte-by-byte.
• Lossless intermediate for further conversion — Netpbm tools (pnmtojpeg, pnmtopng, pamtotiff) use PPM as a hub format. Extract once from VOB and pipe through any Netpbm utility without re-decoding the MPEG-2 stream each time.
• Archival reference frames — A PPM is byte-stable forever. Codec libraries change, MPEG-2 decoders drift slightly between versions, but a P6 raster decoded today equals one decoded in 2040. Useful for legal evidence, archive masters, or before/after comparison.
• DVD-to-print stills — Pull a high-DPI key frame from a home-movie DVD, save as PPM, then open in Photoshop or GIMP and re-export to TIFF for print without quality loss across the chain.
• Avoiding MPEG-2 patent issues in downstream code — Decoding MPEG-2 in your own application still requires licensing in some jurisdictions; reading PPM frames does not. Doing the decode once via XConvert lets the rest of your toolchain stay patent-clean.

VOB vs PPM — Format Comparison

Bit Depth & Resolution Quick Guide

For other extraction targets, see VOB to JPG (smallest files), VOB to PNG (lossless with transparency), or VOB to BMP (uncompressed, Windows-native). To work with the video itself instead of frames, VOB to MP4 is the usual pick.

Frequently Asked Questions

Why is my PPM file so much larger than the source VOB?

PPM stores every pixel verbatim — no compression. A single 720×480 NTSC frame at 8-bit RGB is 720 × 480 × 3 ≈ 1.04 MB. A 1080p frame is roughly 6.2 MB. By contrast, MPEG-2 in a VOB averages ~5 Mbps for that same 1080p picture, which works out to a few hundred KB per second of video across many frames. PPM trades size for byte-stable simplicity; if you need smaller files for the same exact pixels, convert the PPM to PNG for lossless compression at typically 30-60% of the PPM size.

Which PPM variant does XConvert produce — P3 (ASCII) or P6 (binary)?

XConvert writes binary P6 PPM by default, which is what every modern library expects. P6 stores the header in ASCII (magic number, width, height, maxval) followed by raw binary RGB triplets. P3 (the ASCII-text variant) is roughly 3-4x larger and is mostly used in teaching examples. Almost all readers — OpenCV, ImageMagick, GIMP, Netpbm utilities, scikit-image — handle both, but P6 is the practical default.

What time format does Specific Frame accept?

Plain seconds with optional milliseconds: 0, 12, 12.5, 2.100 (= 2 seconds and 100 ms), 90.250. Set the dropdown to Seconds. The timestamp is measured from the start of the VOB segment you uploaded, not from the beginning of the whole DVD title. If your DVD splits a movie across VTS_01_1.VOB, VTS_01_2.VOB,..., upload the segment containing the moment you want, then compute the offset within that segment.

Will I get a frame per second of video, or just one frame?

It depends on the mode. Specific Frame yields exactly one PPM at the timestamp you give. Multiple Screenshots extracts frames on a fixed schedule — the dropdown ranges from every 1/10 second (10 fps capture) down to every 10 seconds. NTSC DVDs run at 29.97 fps and PAL at 25 fps, so picking "every 1/10 second" still skips most frames; choose the rate that matches your downstream analysis.

Are NTSC DVD frames really 720×480, or is that anamorphic?

The raw raster is 720×480 for NTSC and 720×576 for PAL, but DVDs use non-square pixels: 4:3 content displays as 640×480, 16:9 widescreen as 854×480. XConvert outputs the raw raster by default (720×480) — if you need square-pixel display geometry, set Width × Height to 640×480 or 854×480 manually, or pick a Preset Resolution that matches your target.

Can I extract frames from a copy-protected DVD?

XConvert processes the VOB file you upload, but it does not decrypt CSS-protected DVDs. If your DVD is CSS-encrypted (most commercial Hollywood discs are), you'll need to rip with a tool like MakeMKV or HandBrake — which decode CSS where legally permitted — to get a usable VOB or MKV first, then upload that to XConvert for PPM extraction. Home-movie DVDs and authored DVDs without CSS work directly.

Why does my extracted frame look interlaced or combed?

DVD video is often interlaced (480i, 576i), meaning each "frame" is actually two fields captured at different moments. Extracting a single raster from interlaced source produces the comb-tooth artifact when the picture moves. Pick a higher Preset Resolution so XConvert applies deinterlacing on the upscale, or extract a frame from a less-motion segment of the video. For source video that you know is progressive (480p / 576p / authored from a digital master), this is not an issue.

Can I batch-convert every VOB segment in a VIDEO_TS folder at once?

Yes. Drop all of VTS_01_1.VOB, VTS_01_2.VOB, VTS_01_3.VOB,... onto the uploader together. Each one is processed independently with the same Frame Selection and Bit Depth settings. If you want one frame from each segment, use Specific Frame; if you want a full timeline of stills across the whole title, use Multiple Screenshots and let the rate set how many PPMs you end up with per segment.

How big can the input VOB be?

VOB files on a DVD are capped at 1 GiB per segment by the DVD-Video spec, and XConvert handles the full GiB without issue. There's no fixed per-file cap on the upload side either — the practical limit is upload size and connection speed and upload bandwidth. If your source is already an MP4 instead of a VOB, MP4 to PPM takes the same frame-extraction path.