Color bars are an important reference, both for system line-up and for diagnostics. There are plenty of inaccurate bars floating around on the 'net, and the fact that not all codecs encode RGB images the same way only complicates the matter. I've gone the extra step and encoded mathematically-correct bars using a DV codec of known quality and RGB/YUV mapping

I've taken Bob Currier's excellent free utility Test Pattern Maker and generated his "SMPTE-style color bars" pattern, coding "RGB (0-255) no setup", which yields the most accurate output when encoded into DV video*. I then read the TGA files into Premiere using the top-notch Matrox software codecs, and generated single-frame AVIs of the bars in DV/DVCAM, DVCPRO, and DV50 formats. All bars are "NTSC", 480 lines tall.

The AVI files contain "pure" YCrCb bars, which should play back properly calibrated in any NLE and any hardware codec, regardless of RGB mapping, as long as you have a codec that supports DV, DVCPRO, or DV50 compression respectively. (Note that the DVCPRO50 bars are 720x480, not 486 as they should be. This is an artifact of the Matrox codec, designed to be compatible with the 480-line C-Cube hardware codec used in DigiSuite DTV.)

As these are Microsoft VfW AVI images, they are loadable by Video for Windows, OpenDML, and QuickTime-based editors alike.

I have tested all three sets of bars in a DigiSuite DTV, which supports all three formats. I have also examined the DV bars in DPS Spark and in Final Cut Pro to ensure that they are correct.

Right-click (PC) or Control-click (Mac) these links and select "Save to file" to get these bars for your own use. If you simply click on them, you may see the DV/DVCAM bars, but unless you have a D-7 or DV50-compatible codec on your system, you will likely get an error message of some sort, or a white screen if QuickTime tries to load 'em!

* That is, all the vectors hit their targets exactly, blacks are encoded at Y=16 in the digital domain, and the output looks correct when "add setup" is selected in a DVCAM/DVCPRO deck's menu, or when the WFM is tweaked to "add setup" when using a setup-challenged DV VTR. All of the other options for color bar coding result in undersaturated color either all around or along the R-Y axis, at least using any of the software DV codecs I have at my beck and call.

Be aware that the -I and Q patches are approximations and will not line up on a vectorscope. Also, since this image originates in 0-255 RGB space, the "5 IRE" PLUGE bar is missing as a blacker-than-black image can't be rendered in 0-255 RGB color space.

The "add setup" versions of the test pattern codings, while yielding an appropriate-looking setup on the analog outputs of a DV deck, result in a nonstandard black coding in the digital domain as well as color saturation errors.

 

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