Reply To: Let's talk about picture quality: An in depth discussion.

[patrickm]

The standards I’m referring to are simple and universal: avoid flaws in the picture. Just like stretching a 4:3 movie image to fill the screen is not how the artist originally intended for the image to be displayed, the artists did not intend for the pixels to be stretched by varying amounts, and yes, this will have an impact on pixel art, particularly as objects scroll across the screen.

The 6×5 scale thing I’ve explained numerous times and even included a side by side comparison with a real crt as evidence. In fact, my Sanyo CRT cropped slightly more than the emulated image at 6×5 scale, and yet still you claim that I’m cropping too much off the image!

I will explain it again. An NTSC CRT cropped off up to 10% of the picture from the top and bottom of the picture. This area was called overscan and was not meant to be displayed. If your TV displayed this, it was calibrated outside of what the developers intended. The 90% of the picture that remains is what is referred to as the “safe area” and all television programs and movies were designed so that important graphics were not displayed outside of this area. And in fact, the overscan area would often have things you weren’t supposed to see; such as boom mics in television programs or junk pixels on NES games. So, the amount that is cropped at 5x scale is actually closer to how the game was displayed on a CRT TV than displaying the entire uncropped 4:3 image in a letterboxed window.

In case you missed the calculations I provided earlier, here they are again: the safe area of an NTSC TV is 90% of the area, top to bottom. On the NES, 5x scale is 1200 pixels. So on a 1080p display, you drop off 120 pixels. But each NES pixel is 5 1080p pixels at 5x scale. 120 / 5 = 24 pixels, or exactly 10% of 240.

With Snes or Genesis, what gets cropped off is so minimal its not even worth discussing (like 4 pixels)

The pixel dimensions as well are well within the parameters set by CRTs- you aren’t really appreciating the degree to which this varied by individual CRT. CRTs cropped varying amounts off of the top, bottom, and sides and stretched the image by varying amounts to achieve this. There is no single standard here when it comes to pixel dimensions, only a correct range. Basically, any pixel height/width ratio that is above 1:1 (the pixels were never square on a CRT) but below 1:1.43 (the dimensions when nothing is cropped) is technically fine and is within the parameters set by CRTs.

The aspect ratio is also arbitrary and a consequence of the display being used. The only impact this would have on the game graphics is that the artists would have expected a roughly 4:3 output that would have stretched the output frame by a certain amount. But again, because each TV stretched and cropped everything by varying amounts, the graphic artists could only expect a certain range, here.

My personal preference is 6×5 scale but my suggesting settings will work at any scale, provided that the right overlay is used- 5x scale needs a 5x overlay while all scales below this can use the 4x scale overlay. The 6×5 scale image is more accurate IMO because it doesn’t show the overscan.

“So I understand Your statement that a picture in which some stroke are very clear to see, but spoil the image in any case, is better for all people, as the same picture, in which these lines but can not be seen ..?”

No, I’m afraid you didn’t understand the analogy; allow me to explain. I’m using a hypothetical example here to illustrate a point.

The image is clearly flawed if a use a black pen to draw some random lines across the television. Or, better yet, suppose that there are several dead pixels on the lcd screen, so that they no longer produce any light or color. But suppose my grandmother is almost blind and can’t see the lines that I’ve drawn or the dead pixels. She thinks it looks okay.

The point is that just because someone doesn’t notice flaws, doesn’t mean that they aren’t there or that they aren’t flaws. A dead pixel is a dead pixel and it’s a flaw. By analogy, the same is true of warped pixels.