EVOGENIO® - Evolutionäre Kunst

BasicLevel - EvoArt - EvoArt1 -  EvoArt2

Dr. Günter Bachelier -

The second Evolutionary Art processes (2004-2007)

img12The second evolutionary art process was developed in 2004 using some additional concepts, such as a global image pool, image templates (as an analogy to the genome), multi-sexual recombination and specific types of meme reproduction, as a translation of the ontogenetic concept of spores or fruits.


The process begins with the definition of a template image that consists of several masks, each on one layer (see point 2 in fig. 1). A multi-sexual reproduction process (see point 3 in fig. 1) exchanges those masks randomly by images from a global image pool  (see point 1 in fig. 1) that consists of several classes of images. Recombination strategies define which mask is exchanged by an image from  which class. This reproduction is multi-sexual because more than two layers and image parents are always selected.

Fig. 1: Overview of the second Evolutionary Art Process

After generating a population of about 100 individuals, the evaluation is done by the artist putting each image in one of three classes:
After the time-consuming manual optimization, (see point 4 in fig. 1) the images from the second and third classes are directly copied into the global image pool in their own class (see point 5 in fig. 1).

Additionally, they undergo a second reproduction phase where mathematical symmetry operators with random but constrained parameters are applied to them (see point 7 in fig. 1). Forty to eighty meme images  were generated for each symmetry operator. These images were directly inserted into the global image pool, where every symmetry operator used has its own image class. Images from the first and second reproduction processes are then available for selection in the next iteration or generation, where the same or a different image template is used.

Global image pool

A huge global image pool consisting of pixel images is provided. The images come from non-evolutionary art processes such as self-organizing painting  and from previous evolutionary runs. The image pool is structured into different classes, (see imagetyp-T10, T14, T17, M, and S in fig. 1) depending on the origin and method of generation. Many of the image individuals from the first evolutionary art processes are included in a specific image type S, called "Spaces". These individuals are often used as background (first layer).

The idea of a predominant image or meme pool is derived from the idea of genetic load {Born1978}: Preserved genes from the evolutionary history of a population or a species to be used now or later. These genes were originally included in the gene structure of the individuals, but in my evolutionary art process all memes were externalized in the image pool where they are used for recombination purposes. Such a predominant image pool has no close biological analogy because it represents not only all the genes of a present ecosystem, but also the whole history of such an ecosystem.

Initialization by determination of an image template

An important building block is the use of an image template in analogy to a genome. A genome is defined by a certain number and position of genes. A certain number of masks and their position to each other exemplify the analogy in this evolutionary art process. Each mask is located on a specific layer of the image template. The masks and their composition in the template are generated by the artist and they reflect my interest in the dependencies between symmetry and symmetry breaking. In most cases, bilateral symmetry is used for the masks.

Recombination of image individuals

A population is defined by a number of image individuals. Those image individuals are generated by using a multi-sexual recombination process that randomly takes images of the image pool and exchanges the content of masks  by the corresponding content of the selected images (see fig. 2). This recombination process has a similarity to the multi-sexual recombination of viruses where more than two individuals recombine to build offspring. The gene pool is the set of all individuals that ever existed which corresponds to the image pool.

Fig. 2: Recombination with a template and masks

There are lots of possible recombination strategies which determine what type of image should be used for one of the masks. It is part of the artist's task to specify such strategies. An actually used recombination strategy specifies that for the background layer (layer 1) a random image is chosen from the class "Spaces from the year 2004", for layer 2 a random image is chosen from imagetyp-T14 (plane group p3m1), for layer 3 a random image of imagetyp-T14 or imagetyp-T10 (plane group p4m) is chosen, for layer 4 a random image is chosen from imagetyp-T17 (plane group p6m), and for layer 5 a random image is chosen from imagetyp-M (image individuals that were directly transferred to the image pool, see point 5 in fig. 1):
A huge flexibility can be generated if the masks are previously transformed into paths. In this case, the images from the image pool are inserted and  then they undergo a RST-transformation before they are transformed together with  the path into a new mask or stencil.


After having generated a population of roughly 100 image individuals, the images are evaluated by the artist by putting them into one of the following classes "non-reproduction", "optimization" or "direct reproduction".

Manual optimizing

The option of manually optimizing image individuals is specially important when paths are used, given that the probability of images with local faults can be high in this instance depending of the RST-parameters. A fault mask or stencil is built when the RST-transformed image does not fully overlap its corresponding path. Image individuals with one or more of such faults are called "non valid". If the overall impression of such an image is good, then it is selected for the "optimization" class and the fault is reversed by hand by moving the RST-transformed image on the layer in such a way, that it fully overlaps the path, followed by the merging of the image and path.

The detection of non valid image individuals is done manually by the artist during the evaluation, however a script was developed which can automatically detect such individuals if a specific background color is used that is not intentionally used in any of the images. One of the drawbacks of this procedure is the production of "false  positive" detections, i.e. images are marked as non valid because there are pixels of the specific color, though they all have valid masks. A threshold of pixels was introduced in order to minimize the false positive detections: the image classified as non valid only when the number of pixels with such color is above the threshold

Selection for Meme Reproduction

After the optimization of image individuals, the classes "direct  reproduction" and "optimization" are merged and then directly copied into the image pool in the imagetyp-M class. One of the unique features of my new evolutionary art process is that these images or a selected subset of them undergo a second stage of reproduction,  the meme reproduction. In the present implementation, all images from the merged classes are selected for  this second reproduction.

Image meme reproduction

This second stage of reproduction shares similarities with species that  produce fruits or spores. Those fruits or spores have none or few morphological similarities with the parents but they are able to yield offspring by  themselves.

Usually, parts of image individuals are selected and a whole new image can be generated from this part using a system of simple image operations. Given that symmetry is one of my main interests, special mathematical operations (two dimensional symmetry groups or plane groups {GrünbaumShephard1986}) are used to perform this task. There are 17 plane groups and four of them generate seamless images (pmm, p4m, p3m1, p6m). After experimenting in 2004 with all plane groups, three (p4m, p3m1, p6m) of the four seamless plane groups are now used in my evolutionary art process. Every symmetry group defines its own class in the global image pool. The plane group p3m1 fits my  aesthetic preferences very well and it is used the most in the meme reproduction process. From every selected image individual from the first reproduction process, 80 different meme images were generated with p3m1, where p4m and p6m generate 40 each.

The generation of a meme image with p3m1 will be described next in some detail. The process begins with the selection of an image part from the source image,  e. g. M04-05-08b-1-026 (rotated 90° counter clockwise) in fig. 3).

Fig. 3: Building blocks of a seamless plane covering with p3m1

The selection with a polygon selection operation is an equilateral triangle. Its side length is a predefined constant or a function of the side lengths of the source image (e.g. 0.8 of the infimum of the two side lengths). The position of the triangle in the image M04-05-08b-1-026 is random and different in every of the meme reproduction processes. The selected image part, serves as a basic building block, G1, that can be copied and altered with some simple geometric procedures to generate five other building blocks, G2-G6, in the
following way (see fig. 3):
A seamless covering of the plane is possible with those six building blocks. A meme image can be interpreted as a region of such a patterned plane and, as default, the side lengths of the meme image are the same as the side  lengths of the source image (see fig. 4). The resulting meme image is named according to the symmetry used to generate it (here T14 for p3m1) and it is numbered, so the image in fig. 4 could be copied as T14M04-05-08b-1-026-001 in the T14-class of the global image pool.
Fig. 4: Selection of a meme image from the seamless plane covering

Optional selection for insertion in the image pool

The images generated by the meme reproduction process can be copied directly in the global image pool or they can be evaluated. The direct copy option was implemented since evaluation by a human is not reasonable, due to the large amount of meme images and because of the unavailability of an aesthetic preference model that could evaluate these images with machine learning  methods. This approach is also reasonable because experience has shown that meme images generated by the selected plane groups fit, in most cases, the aesthetic preferences, provided the source image was selected according to the same preferences.

Selection for physical transformation

The selection for physical transformation is not part of the evolutionary process in a strict sense, but it is part of my art process in general. It is not only selected here which image should be physically obtained but also all other aspects related to this decision: Size, materials, kind of printing, number of copies printed, etc.


The social sculpture Health Art

Since 2003/04 my evolutionary art process is embedded in my social sculpture "Health Art", therefore the selection for physical transformation is constrained by specific techniques and materials which are compatible with this ecological and health-conscious concept. First, the selected image individuals were printed with acrylic on canvas and then sealed with shellack to avoid toxic emissions from the paint. Then the canvas is integrated in the picture frame with the absorber material that neutralizes and/or binds a large number of gaseous air pollutants.

Change of generations

In evolutionary art processes which are more closely related to the biological processes, there is a change of generation after the reproduction and selection of individuals. The selected offspring or a mixture of parents and offspring build the next generation, followed on by further reproduction and selection processes. In my evolutionary art process there is no change of generation in the this sense, because none of the individuals are  transferred directly to the next generation. Selected individuals and the meme images are transferred instead into the global image pool. This has a biological correlate to species that produce fruits or spores, e.g., plants that live only one year.

Resulting Images

Fig. 5 shows two prototypical image individuals that were generated with this  evolutionary art process. They include most of the factors of my current contrast aesthetics: Concrete art shapes and Informel content, biomorphic {Gielis2003} and hard-edge shapes, shapes with global bilateral symmetry, local and global symmetries and symmetry breaking in the content.

Fig. 5: Two examples of prototypical new image individuals:  M04-05-08b-1-026 and M05-06-11-2-020


BasicLevel - EvoArt - EvoArt1 -  EvoArt2