So i'm trying to get pixel-perfect output from my PC (dell xps15 with intel HD4600) to LG 1080p TV (55EA9800).
I drew a PNG file with single pixel wide vertical lines of pure green, red, blue and when i look at that file using a browser built into TV it displays pixel-perfectly.
However when i connect my PC over HDMI the single-pixel green line is perfect but the blue and red single-pixel vertical lines both have a 1-pixel wide low-intensity halo around them. I'd say the halo is about 5-10% of brightness. If i zoom the lines to 200, 400 or 800% the halo is still 1 pixel wide.
I also verified that there's no actual halo with color picker measuring tool in Photoshop. PNG transparency color is set to pure black.
TV is set to Just Scan mode and I tried every possible setting for Sharpness, Gamma, brightness, contrast etc etc The halo is clearly there.
Any suggestions? My laptop also has mini-DP output and TV has component and composite inputs (but no DVI, only 4 hdmi). I also tried plugging into each of 4 HDMIs. I also tried every possible setting in Intel HD Display Control Panel. Scaling is set to match display and resolution is set to 1080p (which is the native resolution for the TV panel)
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Don't use 1080i. It will transmit the picture in YCbCr which has half the chroma resolution. Set the computer to output RGB. See the 4:4:4 (RGB) and 4:2:2 (YCbCr) images in this post:
Make sure your TV isn't set to overscan. And make sure overscan compensation isn't enabled on the graphics card.
Use the 1920x1080 belle-nuit test pattern for testing. Compare the color and luma lines around the "1" area. You should get the same resolution with each. And you should be able to see every individual line.
Last edited by jagabo; 7th Jun 2014 at 06:34.
Newer TVs often have a labeling system for their connections, make sure that you designate the HDMI connection you are using as "PC" because doing that sometimes also configures that port for a PC. Also check to see if there is "PC Mode" setting that has to be applied to an HDMI port used for connecting a PC.
Also be sure all the "automatic" processing features are disabled -- contrast, saturation, sharpness, noise filters, etc. On both the TV and the computer.