14 votes

Subpixel Rendering for a Ray Tracer

This is perfectly possible Although the difference may not especially noticeable, I would expect sampling taking into account the exact pixel geometry to give a slightly more accurate image. You just ...
  • 5,902
14 votes

How is Anti Aliasing Implemented in Ray Tracing?

Raxvan is completely right that "traditional" anti aliasing techniques will work in raytracing, including those that use information such as depth to do antialiasing. You could even do temporal anti ...
  • 7,381
13 votes
Accepted

How is Anti Aliasing Implemented in Ray Tracing?

I think it's safe to say that there are two different ways of doing AA in raytracing: 1: if you have the final image and the depth image it is possible to apply almost all existing techniques that ...
  • 253
12 votes
Accepted

Anti-aliasing / Filtering in Ray Tracing

There is a great paper from 2006 on this topic, Filter Importance Sampling. They propose your method 2, study the properties, and come out generally in favor of it. They claim that this method gives ...
  • 23.9k
12 votes
Accepted

why does black text have orange and blue pixels

This is called subpixel rendering. The different primary colors in your monitor are not stacked on top of each other. Instead they are arranged near each other. Different monitors have different ...
  • 8,189
12 votes
Accepted

What is Illustrator's vector rasterization process?

As as far as I can tell Illustrator has 2 or 3 different rasterizer. The onscreen preview is also prone to the same gap artifacting as your show though its tuned to minimize the effect. Your post ...
  • 8,189
10 votes
Accepted

How do I accurately compute coverage of overlapping analytical curves?

There is really no good way of doing this efficiently analytically for all corner cases. Most or all commercial 2D renderers that attempt to do analytic coverage calculation make predictable errors ...
10 votes
Accepted

Fast antialiased line drawing

Is there a similarly fast way to draw antialiased lines? No, because by definition an anti-aliased line touches more pixels. Such algorithms will be slower. In a software rasterizer, the ubiquitous ...
  • 1,800
9 votes

Subpixel Rendering for a Ray Tracer

Sure, you can use subpixel rendering for arbitrary images. However, subpixel rendering is really a generic 2D image processing technique — it has nothing to do with ray tracing specifically. ...
9 votes
Accepted

What is the fundamental reasoning for anti aliasing using multiple random samples within a pixel?

From a signal processing point of view, you're sampling a continuous-domain signal, and you need to filter it to get rid of frequencies beyond the Nyquist limit. It's that filtering that leads to ...
  • 23.9k
8 votes
Accepted

What kind of anti-aliasing is used in font rasterization?

Sean Barrett, the author of the stb libraries, wrote an article on how stb_truetype's rasterization works. It's quite readable. The article describes two methods of antialiasing, both based on ...
  • 23.9k
8 votes
Accepted

What is the relation between Aliasing and Flickering?

Flickering can be a form of temporal aliasing. It's a similar phenomenon to spatial aliasing such as jaggies, but it occurs in time instead of space. For instance, a common cause of image flickering ...
  • 23.9k
7 votes

How is Anti Aliasing Implemented in Ray Tracing?

Let's suppose a fairly typical raytracing main loop: ...
7 votes

Relationship between spatial frequency of an image and Aliasing

Like in any other kind of signal processing, the relationship is Nyquist's theorem. An image is a discrete sequence of samples of a continuous signal. If the original signal has frequency components ...
  • 6,510
5 votes
Accepted

How to solve Z buffer artifacts

Short answer: Move your near clip plane further away. Depth buffer precision is very sensitive to the near clip plane distance. Complicated answer: Use different math in your view projection. There ...
5 votes
Accepted

Algorithms to "anti-alias" (or somehow improve) binary 1-bit drawings and fonts

PIL's Image.convert function performs dithering by default when you convert the image to 1-bit—not simply thresholding. That's what creates the noise along the ...
  • 23.9k
5 votes

What is Illustrator's vector rasterization process?

And just to add: it is called "conflation" artifact and this is what AntiGrain Geometry used the compound shapes rasterizer for, see: flash_rasterizer.png http://agg.sourceforge.net/antigrain.com/...
  • 1,369
4 votes

What is the fundamental reasoning for anti aliasing using multiple random samples within a pixel?

You are in fact doing both things. You are integrating the area and because your result is still discrete samples you are reconstructing the signal to make it continious function. Therefore the higher ...
  • 8,189
4 votes
Accepted

How to never draw "Jaggies" in the first place considering resolution and scale

Well you can render at higher resolution and sample down thhis is called FSAA and should just work without much change to render code. FSAA has the benefit of not having a conflation problem whereas ...
  • 8,189
4 votes
Accepted

Sub-pixel antialiasing rules

I'm not sure what happens there. Looking at the rendering of "considerations" in your example, the "cons" looks like what you get when you do crude sub pixel anti-aliasing, without applying the ...
  • 56
4 votes
Accepted

Main techniques to draw a point at non integer coordinates?

Instead of having a binary on/off per pixel you can instead make a heat map. The more points fall within the pixel the brighter the pixel is. Essentially create a 2D histogram which you then ...
4 votes

FXAA vs MSAA on modern hardware

Most mobile GPUs use tiled rendering, which can make MSAA surprisingly cheap relative to desktop GPUs. If the app is doing simple forward rendering without filtering/blurring passes, the GPU may be ...
  • 23.9k
4 votes
Accepted

glBlitFramebuffer does not copy all textures

I think you misunderstood the use of glBlitFrameBuffer. When using this to blit Color Buffers, according to the docs, One thing to keep in mind is this: when using ...
3 votes
Accepted

Unexpected results from Mitchell-Netravali

Mitchell–Netravali has negative lobes, which are generally not recommended for small sample counts from what I understand; you tend to end up with both the positive and negative areas undersampled. ...
  • 23.9k
3 votes

Algorithms to "anti-alias" (or somehow improve) binary 1-bit drawings and fonts

This is just a supplementary answer based on the accepted answer, using the original 64x128 pixel images instead of the zoomed-in interpolated screen shot. ...
  • 330
3 votes

Algorithms to "anti-alias" (or somehow improve) binary 1-bit drawings and fonts

Have a look at Improved Alpha-Tested Magnification for Vector Textures and Special Effects [Gre07] (pdf). The gist of their method is to store distance field information in the font texture instead of ...
  • 800
3 votes
Accepted

Origin of blurring and colour distortion in monochrome diagrams

This looks like JPEG artefacts so I guess the image went through a JPEG compression step at one stage and that permanently introduced noise into the image. The red channel is blurred stronger because ...
  • 2,244
2 votes

Sub-pixel antialiasing rules

What methods are used for sub-pixel anti-aliasing that give such good results? You simply rasterize the letters as if they were 3x as wide. The results differ in the way you rasterize the curves, ...
  • 1,369
2 votes

Points of a line given in global coordinates to calculate the pixels that are set using the midpoint algorithm without anti-aliasing

When drawing objects that exist in 3D space to a 2D plane (like your monitor or an image), there are a number of spaces that are useful to work in: Global Coordinates - Somewhere in your 3D world ...
  • 3,331
2 votes

Algorithms to "anti-alias" (or somehow improve) binary 1-bit drawings and fonts

In the olden days, for things like fonts, they didn't do antialiasing. They generally hand made bitmap fonts because it generated the clearest, easiest-to-read results. That said, you could look into ...
  • 3,331

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