![]() ![]() At this test, not scaled videos (Full or Partial range) wrongly displayed as two large squares of black and white with a numbers or shaded a lot. Scaling required because Partial (TV) color range videos at 8-bit has 16-235 of luma versus 0-255 in Full (PC). For well scaled videos (Full or Partial range), almost all gradations of bright are visible. The detection sign contain "black" rectangles (large size) 16 14 12 10 8 4 0 of bright, and "white" rectangles (large size) 234 236 238 240 244 248 252 255 of bright. There is fast detection test for video Color Range in the next test sign. Sure, the test picture was shifted horizontally, check the test image alignment. If you see two stripes co-siting under the both JPEG and MPEG2 pointers - you got a baby. Note: this test is useful for re-encoding (if you scale or crop - this test fails). Chroma sample aligned to odd columns (left picture, MPEG2 sampling) or centered in 2x2 box (right picture, JPEG sampling): Chroma sample aligned to odd columns (left picture, MPEG2 sampling) or centered in 2x2 box (right picture, JPEG sampling):īT.709 coefficients on encode, 4:2:0 subsampling. when these filters applies to the color planes.īT.601 coefficients on encode, 4:2:0 subsampling. The test based only on horizontal position of the sampling point, it may not work for complex filtering like bilinear, bicubic etc. The match ensures that the named sampling technique is in use. The stripes matches to the corresponding triangle pointers only one at the time. These 2 stripes points to used chroma sampling technique. The greenish for centered sampling (JPEG) and reddish for co-sited to odd columns sampling (MPEG2). Two colored vertical stripes about 2 pixels wide. In case of two thick color stripes, probably you are working with other subsampling or at different scale. The upper part of the test square can has vertical gray stripes or solid gray plate. ![]() This test only applies to the videos with 4:2:0, 4:2:2, 4:1:1 subsampling. Results and test chart readings Color chartsĪt the bottom of the test chart you can see encoding matrix and sampling origin detection test. Do not scale it up or down! For your monitor you may watch video full screen. Watch recorded or streaming video 100% scale.Make sure that image positioned at the top left corner of the OBS Studio Preview window.Select downloaded test chart as input image. Set OBS Studio Settings>Video>Output (Scaled) Resolution to the test chart resolution.Set OBS Studio Settings>Video>Base (Canvas) Resolution to the test chart resolution.Download the test chart (.png image) with resolution equal or less than monitor resolution.That's why I made this new test charts for OBS Studio.Ī) Color space, chroma subsampling, color range test chartsĪll color test charts designed to be viewed in native resolution (scale 1:1 or 100%). Unfortunately, color bars are hard to understand by casual users. Professional studios places color bars at the beginning of the video for this purposes. To view created footage in the right way (true color) you must ensure that all stages of the post production (including web hosts) doesn't introduce color error in your videos. YUV Color Range - this is video range of the resulting footage.Īll this settings applies on encoding.YUV Color Space * - this is standard ** of the color video you are working with.Color Format - this is equal to the chroma subsampling. ![]() without proper matrix) then you'll get color error ("darker" green than it actually should, and "over-bright" green vise versa). If video encoded by BT.601 and viewed as BT.709 (i.e. This is noticable on transformations: original_RGB -> compressed_YUV -> restored_RGB, when color sub-sampling take place in the middle of the process.Īdditional error introduced by gamma and different standards (BT.601, BT.709 etc.) applied to the encoding and decoding. Chroma depend on luma in math calculations, so if you loss some color info - you slightly alternate luminance in some part of the result image.
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