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= Introduction =
= Introduction =
In Kandid a population consist of images looking like abstract
Kandid is a tool for breeding graphics. In Kandid a population consist of images looking like abstract
art or patterns. These graphical forms are not drawn by hand.
art or patterns. These graphical forms are not drawn by hand.
Instead new forms can be found using an interactive genetic
Instead new forms can be found using an interactive genetic
== Pedagogical purpose ==
== What you can learn ==
You can consider Kandid as a simulation of evolution. But compared with the evolution of live there are some differences. The first is how fitness is handled. It needs a human to select the proposed images. Next is the limited range of output. The program can produce lots of color combinations and geometrical shapes. But after using Kandid for a while the style of the images is predictable.
You can consider Kandid as a simulation of evolution. But compared with the evolution of live there are some differences. The first is how fitness is handled. In Kandid it needs a human to select the proposed images. Next is the limited range of output. The program can produce lots of color combinations and geometrical shapes. But after using Kandid for a while the style of the images is predictable.
You can use Kandid to improve you aesthetic feeling. Most of the random images are too indifferent. But sometimes you find a surprisingly interesting composition of shapes or color combinations. Maybe you see things you never noticed before.
You can use Kandid to improve you aesthetic feeling. Most of the random images are too indifferent. But sometimes you find a surprisingly interesting composition of shapes or a god looking color combination. Maybe you see things you never noticed before.
You can use Kandid to get in touch with art made by machines. Ore more precisely: Art made by humans trying to control an generative random process.
You can use Kandid to get in touch with art made by machines. Ore more precisely: Art made by humans trying to control a generative random process. You can see the success and the limits of this algorithmic approach for making art.
Kandid is also about complexity. Ever single image produced by Kandid is made of simple shapes and color schemata. But combining these parts will result in a complex looking image. The result is more than simply summing up the details.
= Usage =
= Usage =
=== Where to get Kandid ===
=== Where to get Kandid ===
[[Image:kandid-evolved-population.png|400px]]
[[Image:kandid-evolved-population.png|400px]]
=== Tweak the control ===
=== Tweak the control ===
== Exporting images to an image manipulation program ==
== Exporting images to an image manipulation program ==
You can send an image to the journal and later open it with an image manipulation program. The images are exported in Portable Network Graphics (PNG) format. The RGB colors and the alpha channel is included. In the population view all images are painted on a black background. If the image is partial transparent you see this black background shining through. After loading an exported image to an image manipulation program it my look different. Depending on your image manipulation program a white background or a checkerboard is looking through.
= Looking inside the image generating process =
= Looking inside the image generating process =
=== What you see is a combination of simple signs ===
=== What you see is made of several layers each containing only simple signs ===
The image rendering is made from simple geometrical shapes. For example select a letter from the alphabet or a mathematical sign an draw it repeatedly on an drawing canvas. Or subdivide the drawing area in four smaller squares, pick some of these little squares by random and repeat this process for several times.
Or select a bulk of points by random and paint a smooth curve using these points.
Each of this rendering algorithm draws its output to an separate layer. The final image is a combination of less than dozens of these layers. The layers are organized as a tree. The finally visible layer is composed from two secondary layers. The secondary layers are combined from layers below. Until you reach one of the leaf of this image rendering tree. There are different strategies for combining two layers. A simple example is adding the color values of two layers to build the resulting layer. A more complex composing strategy is using one of the layer as an mask channel to clip the other layer.
Kandid can display all the details an image is made from. Select "Explain details" and wait a view seconds. Then the program shows a scrollable view with all images layers and how they are combined. The final image is made of nothing more the the displayed details but the effects during composing are often hard to understand.
=== Offspring images differ from there parents ===
Select "Show ancestor" to display a family tree of an newly breeded image. On the top of the page you see the youngest image and below its ancestors. Sometimes the offspring looks different form its parents. This has two reasons. One is mutation. In this case the impact of the mutated parameters takes precedence over the inherit genome. The other reason are genome information that have no visual effect in the parent, but now in the offspring it is visible. Don't confuse the details view and the ancestor view. In the details view you see all the elements an image is made off. In the ancestor view you see the final images from earlier generations.
= Kandid and genetic programming =
=== Phenotype ===
The biological term phenotype means all the visible aspect of an individual creature. Think of the physical appearance of beech trees. The visible representation in Kandid are digital images displayed on your computer screen. In terms of evolution biology this images can be called the phenotype.
=== Genotype ===
The internally coded genetic information carried by all living organisms are called genotype. This information is stored in the deoxyribonucleic acid (DNA). During reproduction, it is replicated and transmitted to the offspring. The genotype in Kandid is the essential information needed for the image renderer. For simple image types this information can be described in a small set of independent parameters.
=== Genotype to Phenotype Transformation ===
The physical representation of an individual creature is determined by two factors its genetic information and the environment. In biology the simple equation <tt>Phenotype = Genotype + Environment</tt> will describe this. In Kandid the genotype will be rendered to visualize the image. The equation can be simplified to <tt>Image = Genotype + Renderer</tt>. The rendering is done with algorithms developed for fractal and Euclidean geometry.
=== Fitness Function ===
In traditional genetic programming a function is needed to calculate an indication how optimal a genome is. This is called fitness function or fitness landscape. The parents with the best results are preferred producing offspring. Unfortunately some problems, like producing interesting digital images, don't have mathematically defined fitness functions. Therefore Kandid has no build in fitness function. No assumption is made how meaningfully an image is for the user. Kasimir Malewitsch 'black square on a white field' can be reinvented with Kandid. But must user wold prefer more colorful images.
=== What you see is made of several layers ===
=== Interactive Genetic Algorithm ===
Instead of a mathematical fitness function the user must weight the relevance of the results. The user has to mark his favorite image in every generation. This is called an interactive genetic algorithm based on human aesthetic selection. Because of the users decreasing concentration the result, an interesting image, must be found in only a few generations.
=== Different evolution Strategies ===
There are different paradigms for implementing a genetic algorithm. ''Evolution Strategies'', invited by Ingo Rechenberg, are suitable for evolving real valued parameters to optimizing the result of a fixed formula. ''Genetic Algorithms'', introduced by John Holland are also for optimizing parameters in hard coded functions. Where the parameters are binary coded instead of floating point numbers. Genetic operations in Kandid can be better understand as 'Evolution Strategy''. But this abstract dispute.
=== Mutation ===
The mostly used mutation operator for elementary values is multiplying the original value by an Gaussian random number. A mutation will lead to an new value that is only slightly different from its original. Random Gaussian numbers varies around 0.0 and small values are much more likely than large numbers. This is the basic mutation schema in an Evolution Strategy. Boolean values in Kandid are toggled. Integer values are incremented or decremented. Points are moved in 2D space by a random angle and a random distance. Color values are perturbed in hue, saturation, brightness space. The operations are implemented in a way that the mutated value is never outside the defined boundaries.
Mutation of a list of predefined elements is implemented by exchanging elements in the list. Two elements are picked randomly and then exchanged. A second list mutation operator is able to expand or reduce a list by one element. In case of expanding the list the newly added element has a random content.
=== Crossing over ===
Merging two genes is called crossing over. It is only used in sexual reproduction. Genetic algorithm can be implemented only with mutation operations. The advantage of crossing over is that the successor gene can take profit from both parent genes. Crossing over is a list operation. The new merged gene list is created by copying elements from both list step by step. At every step a random generator decides between continuing with the current list or changing to the other list as a source for the copying. This leads to multiple crossing over points per gene sequence.
= Releases, translation and known bugs =
= Releases, translation and known bugs =
Developers can clone the source code repository from http://git.sugarlabs.org/projects/kandid/repos/mainline
Developers can clone the source code repository from http://git.sugarlabs.org/projects/kandid/repos/mainline
== Translations ==
== Translations ==
Kandid is partial translated to 'de', 'el', 'en', 'es', 'fr', 'it', 'pt_BR' and 'vi'. The program is translatable using Pootle. See [http://translate.sugarlabs.org/ our Pootle server] for details about how to translate Kandid into your language.
Kandid is partial translated to 'de', 'el', 'en', 'es', 'fr', 'it', 'pt_BR' and 'vi'. The program is translatable using Pootle. See [http://translate.sugarlabs.org/ our Pootle server] for details about how to translate Kandid into your language.
== Bug tracking ==
== Bug tracking ==
Users can report bugs and suggest an enhancement to [http://bugs.sugarlabs.org/ http://bugs.sugarlabs.org/]. Use Trac component name 'Kandid'.
Users can report bugs and suggest an enhancement to [http://bugs.sugarlabs.org/ http://bugs.sugarlabs.org/]. Use Trac component name 'Kandid'.
== Version history ==
== Version history ==
=== v5: Aplril 2010 ===
=== v5: April 2010 ===
* Added a simple ancestors view. The ancestors of newly generated will be displayed as a tree. This is only a temporary solution and should be replaced later.
* Added a simple ancestors view. The ancestors of newly generated will be displayed as a tree. This is only a temporary solution and should be replaced later.
* Added a layer for rendering quadtrees.
* Added a layer for rendering quadtrees.
* Bug fixing samplers / rendering engine. The changes in the rendering engine are not backwards compatible.
* Bug fixing samplers / rendering engine. The changes in the rendering engine are not backwards compatible.
* Saving and restoring the graphics context in modifier nodes. Maybe this bug fix is not backward compatible.
* Saving and restoring the graphics context in modifier nodes. Maybe this bug fix is not backward compatible.
=== v4: February 2010 ===
=== v4: February 2010 ===
* Images generated by Kandid can be exported as PNG images to the journal. You can open an exported image with an image manipulation program.
* Images generated by Kandid can be exported as PNG images to the journal. You can open an exported image with an image manipulation program.
* Improving the color scheme.
* Improving the color scheme.
* Cancel obsolete rendering task during start up. This may reduce time when starting from journal.
* Cancel obsolete rendering task during start up. This may reduce time when starting from journal.
=== v3: January 2010 ===
=== v3: January 2010 ===
* Some new views added to Kandid:
* Some new views added to Kandid:
** The status view is for monitoring the programs internal state.
** The status view is for monitoring the programs internal state.
* Scalable vector graphics (SVG) and Unicode characters will be used as stamps.
* Scalable vector graphics (SVG) and Unicode characters will be used as stamps.
=== v2: December 2009 ===
=== v2: December 2009 ===
* first public release
* first public release