Abstract
This article goes into depth around four different types of noise generation algorithms. We cover the implementation as well as performance information for Perlin, Simplex, Wavelet, and Worley noise. This is an analysis of the implementation and the pro’s and cons for each.
Keywords: Noise, Simplex, Wavelet, Value, Worley, Perlin, texturing
Introduction
Noise is a random disturbance in a sample which is not part of an expected result. Think of audio signals on images that you take with your Digital SLR. The noise is the pieces of information that are not desirable such as hiss or speckled spots on low light photos. In these instances this extra information is usually undesirable but in some application this noise makes things more natural and realistic when using random information.
There are many different applications of noise in game development from terrain generation, procedural textures, to artificial intelligence and many more. Noise is surprisingly interesting and is not necessarily just random numbers. Its about how are those numbers distributed how to they relate to previous information. This can be quite a complex topic and in this blog post I will be going through the following types of noise and providing source code and libraries you can leverage to create applications. The types I am going to cover are:
 Value
 Perlin
 Simplex
 Worley
Research Method
The process I am going to take here is focused around implementing and comparing results of each of the noise generation functions. We will compare the following qualitative values:
 Implementation Difficulty
 Resulting graphical noise
The quantitative values we will leverage are:
 Processing time for various image sizes
 Aggregate variance from white
Results
Noise can be a fairly complex topic with a large amount of information on the topic that varies from article to article. We aim to resolve a number of the difficulties with this article as well as provide a complete set of code and framework that can be reused or inspected. Noise functions do not necessarily generate those beautiful pictures you are used to seeing, it’s the layering and adding those layers together which has those various effects.
In order for us to understand these various noise functions we need to compare it to a purely random function. For this we will be leveraging each of the languages random function to generate a number between 0.0f and 1.0f. We will attempt to stick to floating points as much as the language will allows us to. This is in an effort to ensure consistency between the results. Simply put:
1: function RandomNoise(){
2: return random(0.0f,1.0f);3: }
1. Random Noise
We take the result of the RandomNoise Function and convert it to an RGB value between 0 and 255. For this article we will stick to shades of grey so the RGB values will all be the same.
1: int r = g = b = randomvalue * 255
The results of the RandomNoise function look as follows:
Figure 1.0 Noise Pattern
For an image 300px x 200px the average generation time sits in the 1600ms time range in JavaScript. As you can see there is no uniformity to the noise generated. The performance per language is broken down as follows:
Language  300x200  1024x768  1600x900  1280x1080 
Javascript  7.6  44.8  70.6  65.6 
C#  3.12358  9.37525  20.30747  20.31865 
C++ 
Table 1.0 Random Noise Average Time per resolution
As you can see the performance is purely based on the number of pixels you are trying to generate as well as the language you are using.
Before we go into Perlin Noise there is a bit of understanding of the different types of interpolation that we need to have. Interpolation calculates a projected value between a set of points based on various functions or techniques.
Linear interpolation performs curve fitting using linear polynomials. It takes in 3 inputs Point1, Point2 and t which is a range between 0.0 and 1.0. The function for linear interpolation we will leverage is:
1: function lerp(v0, v1, t)
2: {
3: return v0+(v1v0)*t;4: }
Cosine interpolation is a form of trigonometric interpolation which will provide us with smoother interpolations than linear. The function we will leverage is:
1: function cosinerp(v0, v1, t)
2: {
3: ft = t * 3.1415927
4: f = (1  cos(ft)) * .5
5: return v0*(1f) + v1*f6: }
Cubic interpolation is a more complex form of interpolation but results in much higher amounts of smoothing between points. Its also one of the simpler options to implement although it does require 4 points and t a range which works similar to the other two versions of interpolation. CatmullRom is a variation of this with weighted multiples applied to the calculation (See source code). The implementation is as follows:
1: function cuberp(y0, y1, y2, y3, mu)
2: {
3: a0,a1,a2,a3,mu2;
4: mu2 = mu*mu;
5: a0 = y3  y2  y0 + y1;
6: a1 = y0  y1  a0;
7: a2 = y2  y0;
8: a3 = y1;
9: return(a0*mu*mu2+a1*mu2+a2*mu+a3);10: }
Hermite interpolation is similar to Cubic except with the addition of two parameters Tension and Bias. Tension tightens up the curvature of the points and bias twists the curve around specific points. The formula for Hermite interpolation is:
1: function hermiterp(v0, v1, v2, v3, t, tension, bias){
2: var m0,m1,t2,t3;
3: var a0, a1, a2, a3;
4: t2 = t * t;
5: t3 = t2 * t;
6: m0 = (v1v0)*(1+bias)*(1tension)/2;
7: m0 += (v2v1)*(1bias)*(1tension)/2;
8: m1 = (v2v1)*(1+bias)*(1tension)/2;
9: m1 += (v3v2)*(1bias)*(1tension)/2;
10:
11: a0 = 2*t3  3*t2 + 1;
12: a1 = t3  2*t2 + t;
13: a2 = t3  t2;
14: a3 = 2*t3 + 3*t2;
15:
16: return(a0*y1+a1*m0+a2*m1+a3*y2);17: }
We also need to understand some terminology before proceeding as I found that without a decent understanding of these terms the following explanations become somewhat difficult to understand first time round. These concepts are focused on how layers are added together and the various properties of the layers.
Octaves: this first term is how many layers of noise are we going to blend together. The more octaves or layers the more detail the noise has
Frequency: this is the number of segments that we are going to put into the space we are using. This is the same as frequency when it comes to sound waves or signal process. The lower the frequency the bigger the features and the higher the frequency the smaller the features.
Amplitude: this is the height of the details. The bigger the amplitude the bigger the height of the features. Generally one will decrease the amplitude for each octave to have a more general smoothing effect.
Persistence: This is the rate at which the amplitude will decrease with each octave that is added. The smaller the persistence the lower the amount of change
With these concepts we can multiply and add various layers of noise together to generate wood like textures, clouds and many other types of procedural textures.
2. Value Noise
The next one we will look at is Value noise which is one of the simplest. Value noise is a simple algorithm that leverages a grid of random values between 0 and 1 to work out what a pixel should be. Below is a picture of what Value Noise Looks like:
Figure 2.0 Value Noise
The way value noise works is by using a set of points which are randomized and then for each sample between points are interpolated between that set of randomized values. The general flow of this is as follows:
 Generate a set of random values for points
 For the given point calculate the points surrounding
 Get the random value using the surrounding points
 Calculate the difference between the points and use that for your interpolation value
 Interpolate the values
 Return the result
Lets have a look at each of the steps and understand them further. The first stage we generate an array of the appropriate dimension and we assign random values to this. The size of the array can vary quite widely and its worth having a look how the array size affects the out come. For a 2D noise function it will simply be:
1: for(int x = 0; x < size; x++){2: for(int y = 0; y < size; y++){3: RandomArray[x][y] = Random();
4: }
5: }
Now we have an array populated with random values this is our noise information that we are going to use to interpolate to have smooth transitions. Lets have a look at how this works. Given a point we map that point to the RandomArray and interpolate the value from the surrounding values points. We also need to know the position of the point given relative to the surrounding points we use this relative information to determine the interpolation value between two points. Now we interpolate and return the value for the noise. Once we populate our grid it should be something similar to this:
Figure 2.1 Populated Random Grid
Say we have a point 2,3 that we want noise for on an image that is 300x200 pixels wide we will pass in the x and y values multiplied by the inverse of the width and height of the area you wish to fill with noise. eg.
tx = 0,0033333 = 1/300
ty = 0,005 = 1/200
So we pass into the noise function 2.003333 and 3.005 (the red dot on the diagram). We now break down the point passed in into two components, its whole number and the remainder (tx and ty). With the remainder we use a smoothing function to get a new value that is used during interpolation. We then figure out which are the neighbouring points in the generated grid (the green dots on the diagram). We then interpolate the values with each other.
Figure 2.2 The Points used for interpolation to ensure smooth noise.
To view the source code for this please see the source code links in the references section. Below are the performance metrics for the different languages and resolutions.
Language  300x200  1024x768  1600x900  1280x1080 
Javascript  8.2  94  174  173 
C#  2.10057  58.16069  96.27747  94.56971 
C++  1.6  4.7  3.1  0 
Table 2.0 Value Noise Average Time per resolution
3. Perlin Noise
Perlin Noise is the award winning technique developed by Ken Perlin in 1982 and was leveraged in the motion Picture Tron. It is a gradient noise which is a pseudo random technique. Instead of storing random numbers in the grid as in Value noise and interpolating, Perlin noise stores a gradient vector. To get the values we calculate the dot products of each gradient vector. The dot product is then interpolated to get our result which looks like:
Figure 3.0 Perlin Noise
From the above image you can see Perlin noise is less uniform than Value. There are a number of great articles covering the theory behind Perlin noise which are found in the references section but I will do my best to sum up the jist of what is going on at each step. Looking at Ken Perlin’s improved Perlin noise first step is initializing the array p[]. What is array p? The P array allows us to have a predefined pseudo random allocation of number we can use to generate gradients. We could generate this array using the original method defined by Ken Perlins C code but for performance sake we use a predefined list. This p array is populated to fill 512 items.
Figure 3.1 Populating the P array
Now we have an array that can be used for random numbers we will take our input values and begin processing. It is important to note that the input expected is a floating point (eg 0.0333 or 1.0333). This is why we divide the x and y values by the width and height. This gives us a percentage which is the distance across the width or height. Using this adjusted x and y value as input we then find the cube that surrounds the inputs.
Figure 3.2 Components used for the Perlin Noise calculation
Once we have the required components we now calculate the value that we will be using for the interpolation between the various gradients. This is done using a smoothing function which given a value will return the corresponding value that is on a smoothed curve.
Figure 3.3 Smooth curve values for the Lerp
Using this information we use the values in the p[] array to get hash values that we can leverage to generate the gradients for each point. For example given that our x and y values are (0.0333, 0.0333) for x = 0 and y = 0 the hashes would look as follows:
1: A = p[0] + 0 = 151
2: AA = p[A] + 0 = p[151] = 17
3: …
Using those points we now calculate the various gradients for AA,AB,BA,BB and AA+1, AB+1, BA+1, BB +1.
1: x = 0.0333
2: y = 0.0333
3: AA = 17
4: h = 17 & 15 = 1
5: u = 1 < 8 ? 0.0333 : 0.0333 = 0.0333
6: v = 1 < 4 ? 1 == 12  h == 14 ? 0.0333 : 0 = 0
7: a = h & 1 == 0 ? u : u = 0.0333
8: b = h & 2 == 0 ? v : v = 0;
9:
10: return a + b = 0.0333
With each of those gradients we now perform a Linear Interpolation between those using the smoothed values and that’s about it.
Language  300x200  1024x768  1600x900  1280x1080 
Javascript  22.1  259.6  447.7  440.5 
C#  10.91993  178.67824  329.77866  318.2969 
C++  4.6  40.7  70.3  78.2 
Table 3.0 Perlin Noise Average Time per resolution
4. Simplex
Simplex Noise developed by Ken Perlin in 2001 has similar results to Perlin Noise with less computational requirements than Perlin. The idea of Simplex is to divide the N dimensional space into triangles that reduces the number of data points. In Perlin noise we would find the cube that the point we are given in resides and find the points related. Visually the result is not much different from Perlin noise.
Figure 4.0 Simplex Noise
With simplex we are finding the shape that is based on a equilateral triangle and returning fewer points. The major difference Basically it takes the previous grid and skews it and forms triangles for the simplex representation. The gradients for each of the points are then generated and then the rest of the implementation is pretty much the same.
[TODO – Diagram showing the difference between Perlin and Simplex]
The results are good and the performance is much better than Perlin with higher dimensions but it is quite complex to understand
Language  300x200  1024x768  1600x900  1280x1080 
Javascript  36.2  475.7  847.7  820.5 
C#  15.75991  230.19422  418.06524  393.17309 
C++  3  107.6  192.4  182.6 
Table 4.0 Simplex Noise Average Time per resolution
5. Worley
Worley Noise (Aka Cell Noise) was developed by Steven Worley in 1996 which is very useful in generating stone, water or cell noise textures. The way Worley noise works is that is has a random set of feature points. Given a specific point it calculates the distance of that point to the nearest feature point and uses that for the information. The result is seen below:
Figure 5.0 Worley Noise
What is needed is a set of random points which we compare against. Then we calculate the distance from to the nearest point from the point supplied. Worley’s algorithm has a more efficient implementation of this concept which performs the following steps:

Calculates which cube a point is in

Create a random number generator for the cube

Calculate how many points are inside the cube

Randomly assign points in the cube

Find the point closest to the point given

Check neighboring cubes

Calculate the distance
Figure 5.1 How the noise value is determined
We can change our results by changing the number of feature points, the way distance is computed and the size of the grid used. If you invert the image you can see the points and the distance information clearly.
Language  300x200  1024x768  1600x900  1280x1080 
Javascript  764.8  10003.2  18879  17875.9 
C#  906.9245  11532.654  21078.3585  20539.72 
C++  290.1  3866.4  7078.4  6615 
Table 5.0 Worley Noise Average Time per resolution
Conclusion
The various types of noises all have different visual and performance benefits. Below is a visual comparison of each of the different types of noise covered in this article.
Chart 1.0 Comparison of each of the performance factors across the various languages.By far C++ has the best performance compared to the other languages and C# was typically slower than JavaScript but this can be explained by the direct porting of code instead of using appropriate data structures. The last table summarizes the findings.
Table 6.0 Summarized findings
Source Code:
Sharp Noise : https://sharpnoise.codeplex.com/
References:
Bourke, P (1999) Interpolation Methods, [Online]
Available: http://paulbourke.net/miscellaneous/interpolation/ [7 Feb 2014]
(2012) Noise Part 1, [Online],
Available: http://scratchapixel.com/lessons/3dadvancedlessons/noisepart1/ [12 Feb 2014]
(2010) Value_Noise – Explanation of Value Noise, [Online],
Available: http://code.google.com/p/fractalterraingeneration/wiki/Value_Noise [12 Feb 2014]
(2013) Perlin Noise, Wikipedia, [Online],
Available: http://en.wikipedia.org/wiki/Perlin_noise [5 Feb 2014]
Zucker, M (2001) The Perlin noise math FAQ, [Online],
Available: http://webstaff.itn.liu.se/~stegu/TNM0222005/perlinnoiselinks/perlinnoisemathfaq.html [5 Feb 2014]
Hugo, E (2003) Perlin noise,[Online]
Available: http://freespace.virgin.net/hugo.elias/models/m_perlin.htm [5 Feb 2014]
Perlin, K () Noise and Turbulance, [Online]
Available: http://www.mrl.nyu.edu/~perlin/doc/oscar.html#noise [24 Feb 2014]
Perlin, K () Noise Hardware, [Online]
Available: http://www.csee.umbc.edu/~olano/s2002c36/ch02.pdf [26 Mar 2014]
Perlin, K (2002) Improved Noise Reference Implementation,[Online],
Available: http://mrl.nyu.edu/~perlin/noise/ [7 Feb 2014]
Tulleken, H (2009) How to use Perlin Noise in your games, [Online],
Available: http://devmag.org.za/2009/04/25/perlinnoise/ [7 Feb 2014]
Thomas, K (2011) Perlin Noise in JavaScript, [Online]
Available: http://asserttrue.blogspot.co.uk/2011/12/perlinnoiseinjavascript_31.html [26 Mar 2014]
Explanation of Perlin Noise, [Online]
Available: http://code.google.com/p/fractalterraingeneration/wiki/Perlin_Noise [26 Mar 2014]
Simplex Noise, [Online]
Available: http://en.wikipedia.org/wiki/Simplex_noise [26 Mar 2014]
Gustavson, S (2005) Simplex noise demystified, [Online]
Available: http://webstaff.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf [26 Mar 2014]
Explanation of Simplex Noise, [Online]
Available: http://code.google.com/p/fractalterraingeneration/wiki/Simplex_Noise [26 Mar 2014]
Worley Noise, [Online]
Available: http://en.wikipedia.org/wiki/Worley_noise [26 Mar 2014]
FreeTheNation (alias) (2013) Cell Noise, [Online]
Available: http://aftbit.com/cellnoise2/ [26 Mar 2014]
Worley, S, A Cellular Texture Basis Function, [Online]
Available: http://www.rhythmiccanvas.com/research/papers/worley.pdf [26 Mar 2014]
Endre, S (2012) Worley Noise Cellular Texturing, [Online]
Available: http://esimov.com/2012/05/worleynoisecellulartexturing#.Ux790v_MOM8 [26 Mar 2014]
Nouanesengsy, B CSE 782 Lab 4, [Online]
Available: http://www.cse.ohiostate.edu/~nouanese/782/lab4/ [26 Mar 2014]
Rosen, C (2006) Cell Noise and Processing, [Online]
Available: http://www.carljohanrosen.com/share/CellNoiseAndProcessing.pdf [26 Mar 2014]
Appendix A – Data Results
300x200  1024x768  1600x900  1280x1080  
Sample 1  51  136  141  73 
Sample 2  3  38  65  70 
Sample 3  2  34  62  61 
Sample 4  2  33  61  59 
Sample 5  3  33  62  61 
Sample 6  2  37  62  59 
Sample 7  4  34  64  69 
Sample 8  3  36  63  85 
Sample 9  3  35  63  61 
Sample 10  3  32  63  58 
Average  7.6  44.8  70.6  65.6 
Table A.0.1 Javascript Random Noise in milliseconds
300x200  1024x768  1600x900  1280x1080  
Sample 1  13  105  157  142 
Sample 2  6  87  156  140 
Sample 3  7  81  214  237 
Sample 4  14  112  236  229 
Sample 5  10  115  209  215 
Sample 6  6  104  152  150 
Sample 7  6  84  147  148 
Sample 8  7  88  159  148 
Sample 9  7  83  153  168 
Sample 10  6  81  157  153 
Average  8.2  94  174  173 
Table A.0.2 Javascript Value Noise in milliseconds
300x200  1024x768  1600x900  1280x1080  
Sample 1  26  266  414  403 
Sample 2  28  364  449  423 
Sample 3  23  227  432  405 
Sample 4  17  246  430  452 
Sample 5  16  232  436  468 
Sample 6  23  243  442  469 
Sample 7  30  258  448  435 
Sample 8  17  280  468  448 
Sample 9  15  234  482  462 
Sample 10  26  246  476  440 
Average  22.1  259.6  447.7  440.5 
Table A.0.3 Javascript Perlin Noise in milliseconds
300x200  1024x768  1600x900  1280x1080  
Sample 1  41  498  869  827 
Sample 2  35  457  863  874 
Sample 3  36  491  893  815 
Sample 4  35  474  861  837 
Sample 5  36  499  872  849 
Sample 6  35  463  822  788 
Sample 7  33  440  813  771 
Sample 8  33  464  849  862 
Sample 9  45  520  823  797 
Sample 10  33  451  812  785 
Average  36.2  475.7  847.7  820.5 
Table A.0.3 Javascript Simplex Noise in milliseconds
300x200  1024x768  1600x900  1280x1080  
Sample 1  773  9800  17970  17342 
Sample 2  752  10066  18735  18308 
Sample 3  754  10432  18401  18257 
Sample 4  889  11035  20495  17651 
Sample 5  761  9555  18507  18100 
Sample 6  753  9934  18518  18836 
Sample 7  748  10001  20718  17671 
Sample 8  715  9465  17875  17159 
Sample 9  760  10047  19054  17786 
Sample 10  743  9697  18517  17649 
Average  764.8  10003.2  18879  17875.9 
Table A.0.4 Javascript Worley Noise in milliseconds
300x200  1024x768  1600x900  1280x1080  
Sample 1  15,6219  15,6259  15,6243  31,2802 
Sample 2  0  0  31,2503  15,6251 
Sample 3  0  15,6264  15,6251  15,6267 
Sample 4  0  15,6239  15,6247  15,626 
Sample 5  15,6239  0  15,6259  31,2503 
Sample 6  0  0  31,251  15,6264 
Sample 7  0  15,6243  15,5984  15,6518 
Sample 8  0  15,6264  15,6259  15,6243 
Sample 9  0  15,6256  15,598  31,2781 
Sample 10  0  0  31,2511  15,5976 
Average  3,12458  9,37525  20,30747  20,31865 
C# Random Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  0  62,4993  93,7827  93,7233 
Sample 2  0  62,5292  93,7515  93,7524 
Sample 3  0  62,5009  93,754  93,7216 
Sample 4  0  62,5309  93,7228  93,7819 
Sample 5  0  62,5017  93,7516  98,6821 
Sample 6  4,0003  54,0036  99,9782  94,0085 
Sample 7  4,0003  55,0332  99,006  94,0094 
Sample 8  3,9999  53,0043  101,0083  95,0069 
Sample 9  5,0008  53,0039  97,008  95,0032 
Sample 10  4,0044  53,9999  97,0116  94,0078 
Average  2,10057  58,16069  96,27747  94,56971 
C# Value Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  3,0671  187,5339  328,1042  312,5086 
Sample 2  0  187,5314  312,4794  328,1621 
Sample 3  0  187,4756  328,1596  296,8797 
Sample 4  15,6276  187,5044  328,1329  296,8814 
Sample 5  15,6259  171,8792  328,105  312,5053 
Sample 6  15,6256  171,9055  328,1324  323,6092 
Sample 7  14,001  179,0144  329,0262  328,0242 
Sample 8  14,0022  164,5815  328,1325  312,5077 
Sample 9  15,6252  187,4768  312,5345  312,5077 
Sample 10  15,6247  171,8797  374,9799  359,3831 
Average  10,91993  179,67824  329,77866  318,2969 
C# Perlin Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  15,6272  265,6312  468,759  390,6362 
Sample 2  15,6235  218,785  399,3286  390,6338 
Sample 3  15,6255  218,755  421,8578  400,3869 
Sample 4  16,9734  223,7623  406,2314  453,1643 
Sample 5  15,6255  281,228  437,5071  390,6379 
Sample 6  15,6226  218,7575  406,2581  375,0374 
Sample 7  15,6255  218,7275  421,9124  374,9803 
Sample 8  15,6252  218,7841  406,2589  375,0087 
Sample 9  15,6251  218,7562  406,2528  390,6395 
Sample 10  15,6256  218,7554  406,2593  390,6059 
Average  15,75991  230,19422  418,06254  393,17309 
C# Simplex Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  875,0507  11721,8289  21159,6973  20796,8689< 
Sample 2  881,7512  11395,9728  21601,9663  21163,0641< 
Sample 3  937,5188  11781,6182  21021,7052  20026,9773< 
Sample 4  875,0204  11425,826  20934,028  20934,7304 
Sample 5  968,7906  11538,2469  20978,2407  20503,3906< 
Sample 6  875,015  11437,8304  21050,5453  20282,7218 
Sample 7  859,3624  11500,553  21201,9371  20710,8594 
Sample 8  1046,8467  11692,1106  21034,7107  20608,7085 
Sample 9  874,9585  11458,6809  20889,1269  19987,1211< 
Sample 10  874,931  11373,8703  20911,6274  20382,7533< 
Average  906,92453  11532,6538  21078,35849  20539,7195 
C# Worley Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  0  0  0  0 
Sample 2  0  0  0  0 
Sample 3  0  0  0  0 
Sample 4  0  0  0  0 
Sample 5  16  0  0  0 
Sample 6  0  15  0  0 
Sample 7  0  16  0  0 
Sample 8  0  16  0  0 
Sample 9  0  0  15  0 
Sample 10  0  0  16  0 
Average  1.6  4.7  3.1  0 
C++ Random Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  0  47  78  79 
Sample 2  15  31  79  78 
Sample 3  15  32  78  78 
Sample 4  0  32  78  78 
Sample 5  0  46  63  78 
Sample 6  0  47  62  78 
Sample 7  0  47  62  78 
Sample 8  0  47  62  78 
Sample 9  16  47  62  79 
Sample 10  0  31  79  78 
Average  4.6  40.7  70.3  78.2 
C++ Value Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  16  109  187  188 
Sample 2  16  109  187  188 
Sample 3  16  109  187  172 
Sample 4  16  93  203  170 
Sample 5  16  109  188  187 
Sample 6  0  109  188  187 
Sample 7  0  109  188  187 
Sample 8  0  109  188  187 
Sample 9  16  93  194  188 
Sample 10  16  94  203  187 
Average  11.2  104.3  191.3  184.1 
C++ Perlin Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  15  110  187  172 
Sample 2  15  94  203  172 
Sample 3  0  109  188  187 
Sample 4  0  109  188  187 
Sample 5  0  109  188  187 
Sample 6  0  109  188  187 
Sample 7  0  109  188  187 
Sample 8  0  109  203  172 
Sample 9  0  109  188  187 
Sample 10  0  109  203  188 
Average  3  107.6  192.4  182.6 
C++ Simplex Noise
300x200  1024x768  1600x900  1280x1080  
Sample 1  281  3776  6672  6992 
Sample 2  312  3719  7014  6674 
Sample 3  281  4266  7453  6719 
Sample 4  281  4156  7954  6922 
Sample 5  281  3859  7385  6484 
Sample 6  297  4063  6797  6487 
Sample 7  313  3894  6992  6435 
Sample 8  281  3619  6915  6365 
Sample 9  277  3705  6728  6634 
Sample 10  297  3607  6874  6438 
Average  290.1  3866.4  7078.4  6615 
C++ Worley Noise
Originally posted at http://blogs.msdn.com/hemipteran