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未来壁纸的想象作文英语Title: Envisioning the Future of Wallpaper。
In the realm of interior design, the evolution of wallpaper stands as a testament to the seamless blend of functionality and aesthetic appeal. As we gaze into the future, envisioning the potential of wallpaper unveils a tapestry of innovation, merging technology, sustainability, and artistic expression. Let us embark on a journey through the corridors of imagination, exploring the realms of tomorrow's wallpaper.Technological Integration:In the future, wallpaper will transcend its static nature, morphing into dynamic canvases of digital artistry. Imagine wallpaper embedded with micro-LED technology, capable of transforming walls into immersive displays. These intelligent wallpapers could adapt to ambient lighting, mood, or even display custom artworks, seamlesslyintegrating with smart home ecosystems.Furthermore, advancements in augmented reality (AR) and virtual reality (VR) could revolutionize the way we perceive wallpaper. With AR-enabled wallpapers, users could overlay virtual elements onto their walls, from interactive games to simulated landscapes, blurring the boundaries between the physical and digital realms. VR-integrated wallpapers could transport occupants to distant locales, offering a multisensory escape within the confines of their homes.Sustainability and Eco-conscious Design:The future of wallpaper will prioritize sustainability, embracing eco-friendly materials and production processes. Biodegradable wallpapers made from renewable resources such as bamboo, hemp, or recycled paper will gain prominence, offering an environmentally conscious alternative to traditional vinyl wallpapers.Moreover, advancements in nanotechnology could pave theway for self-cleaning wallpapers, equipped with hydrophobic coatings that repel stains and moisture. These innovative wallpapers not only enhance durability but also reduce the need for harsh chemical cleaners, fostering a greenerliving environment.Artistic Expression and Customization:Tomorrow's wallpaper will be a canvas for boundless creativity, empowering individuals to express their unique identities through design. Customizable wallpaper platforms, accessible through online interfaces or mobile apps, will enable users to personalize their living spaces with ease. From abstract patterns to photorealistic imagery, the possibilities for customization will be limitless.Collaborations with artists, designers, and evenartificial intelligence algorithms will yield a diversearray of wallpaper designs, catering to eclectic tastes and preferences. Augmented reality tools could allow users to preview how different wallpapers would look in their spaces before making a purchase, ensuring a harmonious integrationwith existing décor.Health and Wellness Features:In an era where wellness takes center stage, future wallpapers will incorporate features designed to enhance indoor air quality and promote well-being. Bioactive wallpapers infused with air-purifying agents such as activated charcoal or nanoparticles will help mitigate indoor pollutants, fostering a healthier living environment.Additionally, wallpapers embedded with therapeutic elements, such as aromatherapy microcapsules or soothing color schemes inspired by chromotherapy principles, will contribute to stress reduction and mental relaxation. These wellness-oriented wallpapers will not only adorn walls but also nurture the holistic well-being of occupants.Conclusion:As we peer into the horizon of interior design, the future of wallpaper emerges as a testament to innovation,sustainability, and artistic expression. From dynamic displays to eco-conscious materials, tomorrow's wallpapers will transcend mere adornment, enriching our living spaces with functionality and beauty. Embracing technology, sustainability, and individuality, the evolution of wallpaper heralds a new era of design possibilities, where walls become windows to the imagination.。
电视发展过程的过程英语作文The advent of television marked a significant milestone in the evolution of mass media. In its early days, the black-and-white screens and limited channels were a marvel to audiences.As technology advanced, color televisions emerged, offering a more immersive experience and a broader spectrum of programming. The transition from analog to digital broadcasting further enhanced the quality and accessibility of television content.The internet revolution brought about a paradigm shift in how we consume television. Streaming services have transformed the landscape, allowing viewers to watch their favorite shows and movies on-demand, anytime, anywhere.Social media has also integrated with television, enabling real-time interaction and discussion among viewers. This has created a more interactive and communal viewing experience.The future of television is promising with the advent of virtual reality and augmented reality technologies. These advancements are set to redefine the way we engage with our favorite shows, blurring the lines between reality and fiction.In conclusion, the journey of television from its inception to the present has been one of continuous innovation and adaptation. It has transformed from a simple entertainment medium to a complex, multifaceted platform that shapes and reflects our society.。
科技馆所见所闻所感英语作文The Science Museum: A Captivating Journey through the Wonders of TechnologyAs I stepped through the grand entrance of the Science Museum, I was immediately struck by the palpable sense of excitement and wonder that permeated the air. The towering glass atrium, adorned with intricate architectural features, served as a tantalizing preview of the myriad discoveries that awaited me within.Drawn by the allure of scientific exploration, I began my journey through the vast and meticulously curated exhibits. The first display that caught my eye was a towering replica of the Soyuz spacecraft, a testament to the ingenuity and bravery of the early space pioneers. I marveled at the intricate details of the capsule, imagining the daring astronauts who had entrusted their lives to this remarkable feat of engineering.Nearby, I encountered a mesmerizing holographic display that showcased the inner workings of the human body. As I gazed upon the pulsing organs and intricate networks of veins and arteries, I was struck by the sheer complexity and elegance of our biologicalsystems. The interactive nature of the exhibit allowed me to manipulate the hologram, peeling away layers to reveal the intricate dance of cells and molecules that sustain life.Wandering deeper into the museum, I stumbled upon a captivating exhibit on renewable energy. Rows of sleek solar panels and wind turbine models stood as symbols of our collective efforts to harness the power of nature and transition towards a more sustainable future. The interactive displays allowed me to experiment with different energy sources, adjusting parameters and observing the resulting changes in power generation.One of the most awe-inspiring moments came when I entered the section dedicated to the history of computing and technology. The sight of the massive, room-filling mainframe computers of the past juxtaposed with the compact and powerful devices of the present day was a stark reminder of the exponential progress that has been made in the field of information technology. I found myself mesmerized by the interactive timelines and touchscreen displays that chronicled the evolution of computing from its humble beginnings to the ubiquitous presence it holds in our daily lives.As I continued my exploration, I encountered exhibits that delved into the realms of robotics, artificial intelligence, and virtual reality. The seamless integration of these cutting-edge technologies into themuseum experience was both captivating and thought-provoking. I marveled at the dexterity of the robotic arms, the uncanny intelligence of the AI systems, and the immersive nature of the virtual environments.One particular exhibit that left a lasting impression was the interactive display on the future of transportation. Here, I was able to experiment with prototypes of flying cars, autonomous vehicles, and high-speed rail systems. The sheer imagination and innovation on display ignited a sense of excitement and optimism within me, as I contemplated the transformative potential of these technologies to reshape the way we move and interact with the world around us.As I neared the end of my journey through the Science Museum, I found myself drawn to the section dedicated to the history of scientific discovery. The carefully curated collection of artifacts and interactive displays provided a comprehensive overview of the pivotal moments and groundbreaking breakthroughs that have shaped our understanding of the universe. From the ancient astronomers who charted the stars to the modern-day physicists who unraveled the mysteries of quantum mechanics, the museum's exhibits celebrated the relentless pursuit of knowledge and the power of human curiosity.Throughout my visit, I was consistently impressed by the museum'sability to seamlessly blend education and entertainment. The exhibits were not merely static displays but rather dynamic, immersive experiences that invited me to actively engage with the content. The interactive nature of the displays allowed me to tinker, experiment, and explore, fostering a deeper understanding and appreciation for the scientific principles at work.As I reluctantly prepared to leave the Science Museum, I couldn't help but feel a sense of awe and inspiration. The sheer breadth and depth of the exhibits had left me with a renewed sense of wonder and a deep appreciation for the transformative power of science and technology. The museum had not only enlightened me but had also ignited a burning desire to continue learning, exploring, and pushing the boundaries of human knowledge.In the end, my visit to the Science Museum had been a transformative experience, one that had broadened my horizons and instilled a profound respect for the ingenuity and creativity of the human mind. As I stepped out into the bustling city streets, I carried with me a renewed sense of optimism and a deep conviction that the future holds endless possibilities, all waiting to be discovered and explored.。
杂志类英语作文句子Title: The Evolution of Magazines: A Journey Through Time.Magazines have existed for centuries, evolving from simple newsletters to the diverse and interactive publications we know today. This evolution has been shaped by technological advancements, social trends, and the ever-changing needs of readers.In the early days, magazines were primarily newsletters or gazettes, serving as a medium for sharing news and information. These early publications were often government-sponsored and distributed to a limited audience. As printing technology improved, magazines began to emerge as standalone publications, targeted towards specific interests or demographics.The 19th century saw a significant rise in the popularity of magazines. With the advent of steam-poweredprinting presses, magazines could be produced more quickly and efficiently, allowing for wider distribution and a broader readership. Magazines like Harper's Bazaar and The Saturday Evening Post became household names, offering a mix of news, entertainment, and advertising.The 20th century brought further changes to the magazine industry. The introduction of photography and color printing gave magazines a more visual and engaging format. Magazines like Life and Look captured the public's imagination with their vivid photographs and stories. Additionally, the rise of popular culture and celebrity culture led to the emergence of magazines like Vogue and Vanity Fair, which focused on fashion, beauty, and entertainment.The digital revolution in the 21st century has had a profound impact on magazines. With the advent of the internet, magazines have become more accessible and interactive. Online magazines and digital versions of print magazines offer readers instant access to content, as well as additional features like videos, podcasts, and socialmedia integration.Today, magazines are no longer confined to a single format or medium. We have print magazines, online magazines, digital magazines, and even social media magazines. Magazines have become platforms for ideas, trends, and conversations, reflecting the diverse interests and needsof readers.In conclusion, the evolution of magazines is atestament to the adaptability and resilience of the medium. From simple newsletters to interactive digital platforms, magazines have always been a reflection of their times, reflecting social trends, technological advancements, and the changing needs of readers. As we look towards the future, it is exciting to imagine what new forms andformats magazines will take on, and how they will continueto shape our world.。
英语精读阅读文章精选10万年后的人类长这样Just as the human face has evolved considerably since stone age times soit is expected to keep changing in the future.正如人脸自从石器时代以来已经发生相当大的进化，我们可以预见在未来我们的脸庞也将发生不断的变化。
Today the human brain is three times the size of our primate ancestors. As our brains grew so did our heads get bigger, our skulls expanded and our features became flatter.如今，人类大脑是我们的祖先灵长类动物大小的三倍。
随着我们大脑的进化，我们的头变大了，我们的颅骨扩张了，我们的面部特征变平了。
Now with the advent of wearable technology, such as Google Glass, how will our heads and faces evolve in 20,000 years, 60,000 years and even 100,000years from now?如今随着可穿戴传感技术比如谷歌眼镜的出现，在两万年后、六万年后甚至十万年后，我们的大脑将变成什么样子?This was the question posed by artist and researcher Nickolay Lamm from when he quizzed Dr Alan Kwan, who holds a PhD in computational genomics from Washington Universityin St Louis.这是MyVoucherCodes网的艺术家和研究员尼克欧蕾-拉姆向艾伦-坤博士时提出的问题，艾伦-坤博士在圣路易斯华盛顿大学获得了计算基因组学的博士学位。
关于画像的英语作文Title: The Art of Portraiture。
Portraiture, the art of capturing the essence of an individual through visual representation, has been a cornerstone of artistic expression throughout history. From the grandeur of Renaissance oil paintings to the candidness of contemporary photography, portraits offer a window into the soul of the subject, reflecting their personality, emotions, and innermost thoughts. In this essay, we will delve into the significance of portraiture, its evolution over time, and its enduring appeal in the realm of art.To understand the power of portraiture, one must first acknowledge its roots in human history. Since ancient times, civilizations have sought to immortalize their leaders, heroes, and loved ones through various artistic mediums. Whether carved in stone, painted on canvas, or captured in pixels, portraits serve as tangible connections to the past, preserving the faces and stories of those who came beforeus.Throughout the centuries, portraiture has evolved alongside advancements in technology, culture, and artistic movements. In the Renaissance era, artists like Leonardo da Vinci and Michelangelo elevated portraiture to new heights, infusing their works with intricate detail, lifelike expressions, and symbolic elements. During the Baroque period, painters such as Rembrandt and Velázquez experimented with light, shadow, and psychological depth, imbuing their portraits with a sense of drama and introspection.In the modern era, portraiture has undergone further transformations with the advent of photography and digital imaging. From the daguerreotypes of the 19th century to the Instagram selfies of today, photographs have democratized the portrait-making process, allowing people from all walks of life to document their lives and express themselves visually. Moreover, advancements in digital technology have enabled artists to push the boundaries of portraiture through techniques such as digital painting, photomanipulation, and interactive installations.Yet, despite these advancements, the essence of portraiture remains unchanged: to capture the human experience in all its complexity. Whether rendered in oil, charcoal, or pixels, a compelling portrait transcends mere likeness, revealing the inner workings of the human psyche. It invites viewers to contemplate the intricacies of identity, empathy, and connection in an increasingly fragmented world.Indeed, the appeal of portraiture lies in its ability to bridge the gap between past and present, artist and viewer, subject and observer. In a world inundated with fleeting images and superficial interactions, portraits offer a sense of intimacy and permanence, inviting us to pause, reflect, and engage with the human stories they embody.In conclusion, portraiture stands as a testament to the enduring power of art to capture the essence of the human spirit. From the masterpieces of the Renaissance to theselfies of the digital age, portraits continue to inspire, provoke, and illuminate the richness of the human experience. As we gaze upon these timeless images, we are reminded of our shared humanity and the enduring legacy of those who came before us.。
摄影作品要求英语作文The Artistry and Impact of Photographic Works.Photography, as an art form, has evolved significantly over the centuries, from its humble beginnings as a mere tool for capturing images to its current status as a powerful medium of expression and communication. The evolution of photography has been marked by technological advancements, artistic innovations, and the evolution of human perception.The early years of photography were centered around the desire to accurately replicate real-world scenes. Daguerreotypes and wet plate collodion processes were used to capture fleeting moments in time, often with a focus on portraiture and landscapes. These early photographs, though technically limited, possessed a unique charm and immediacy that has captivated audiences ever since.However, as photography matured as an art form,photographers began to experiment with techniques and subject matter that pushed the boundaries of what was considered possible. The Impressionist movement, for instance, influenced photographers to capture the fleeting effects of light and color, while the rise of street photography emphasized capturing candid moments in public spaces.One of the most significant developments in the history of photography was the invention of the camera obscura, which allowed for the projection of an image onto a screen. This technology eventually led to the creation of the first practical camera, paving the way for the development of photography as a medium of artistic expression.In the 20th century.。
照片与数码时代作文英语Title: The Evolution of Photography: From Analog to Digital。
Photography has undergone a significant transformation over the years, transitioning from the era of film and darkrooms to the age of digital imaging. This evolution has not only changed the way we capture and preserve momentsbut has also revolutionized the entire photographic process.Firstly, let's delve into the era of analog photography. In this period, images were captured using film cameras, which relied on chemical processes to record light ontolight-sensitive film. Each roll of film had a limited number of exposures, typically ranging from 12 to 36 frames. After capturing the images, photographers had to developthe film in a darkroom using a series of chemical baths to reveal the latent image. This process required skill, precision, and time, making photography more of an art form than a casual hobby for many enthusiasts.Analog photography had its charm and challenges. The anticipation of seeing developed images for the first time, the artistry involved in darkroom techniques such as dodging and burning, and the tactile nature of handlingfilm all contributed to its allure. However, analog photography also had its limitations. Film rolls were prone to damage, images degraded over time, and the cost of film and developing materials added up quickly.Then came the digital revolution, ushering in a new era of photography. Digital cameras replaced film cameras, capturing images using electronic sensors that converted light into digital data. This innovation offered numerous advantages over analog photography. Digital cameras allowed for instant image preview, enabling photographers to review and adjust their shots on the spot. The ability to store hundreds, even thousands, of images on a single memory card eliminated the need to carry multiple rolls of film. Furthermore, digital images could be easily edited, manipulated, and shared using computer software, democratizing photography and empowering amateurs andprofessionals alike.The transition from analog to digital photographywasn't without its skeptics. Traditionalists argued that digital technology lacked the warmth and character of film, and some feared that it would make photography too accessible, diluting its artistic value. However, the convenience, versatility, and cost-effectiveness of digital photography ultimately won over the masses.In addition to transforming the way we capture images, digital technology has also revolutionized how we store, share, and consume photographs. With the rise of social media platforms and cloud storage services, photographs are no longer confined to physical albums or dusty shoeboxes. Instead, they exist in a digital realm, easily accessible anytime, anywhere. This accessibility has democratized photography, allowing anyone with a smartphone to become a photographer and share their perspective with the world.Moreover, advancements in digital imaging technology have pushed the boundaries of what is possible inphotography. High-resolution sensors, sophisticated autofocus systems, and powerful image processing algorithms have enabled photographers to capture stunning detail, clarity, and dynamic range in their images. From breathtaking landscapes to intimate portraits, digital cameras have unlocked new creative possibilities and fueled the imagination of photographers worldwide.In conclusion, the transition from analog to digital photography has been a transformative journey, reshapingnot only how we capture and preserve memories but also how we perceive and interact with the visual world. Whileanalog photography will always hold a nostalgic charm,digital technology has democratized photography, making it more accessible, versatile, and innovative than ever before. Whether you're a seasoned professional or an amateur enthusiast, the digital age of photography offers endless opportunities to explore, create, and share your visionwith the world.。
In the digital age, the concept of a photo album has evolved significantly. What was once a tangible collection of printed photos housed within a physical album has transformed into a digital repository of memories, accessible at the touch of a button. The transition from physical to digital has not only changed the way we store and view our memories but has also altered the way we perceive and interact with time.A photo album, in its traditional form, was a curated selection of moments captured in time, carefully chosen and arranged to tell a story. Each page turn was a journey back to a specific moment, a recollection of emotions, and a connection to the past. The tactile experience of flipping through the pages, the smell of the paper, and the feel of the photographs between ones fingers all contributed to a sensory experience that was deeply personal and evocative.In contrast, digital photo albums offer a different kind of engagement with time. They are vast, often containing thousands of images that can be sorted, tagged, and searched with ease. The convenience of digital storage allows for an almost infinite capacity, which can be both a blessing and a curse. On one hand, we no longer have to worry about running out of space or the physical deterioration of our photos. On the other hand, the sheer volume of images can make it difficult to curate and engage with our memories in a meaningful way.One of the most significant impacts of digital photo albums on our perception of time is the immediacy with which we can access our memories. With a few keystrokes or a swipe on a touchscreen, we can betransported back to a specific moment in our lives. This immediacy can be both comforting and disconcerting. It allows us to revisit cherished moments and relive the emotions associated with them, but it can also lead to a sense of time being compressed, as the past seems to be just a click away.Moreover, the digital format has also changed the way we share our memories. Social media platforms have become modernday photo albums, where we can instantly share our experiences with a global audience. This has created a new dynamic in how we construct our narratives and how we present ourselves to the world. The pressure to curate an idealized version of our lives for public consumption can sometimes overshadow the authenticity of our memories.Despite these changes, the essence of what a photo album represents remains the same: a collection of moments that define our lives. Whether in a physical or digital form, photo albums serve as a testament to the passage of time and the evolution of our experiences. They are a bridge between the past and the present, allowing us to reflect on where we have been and anticipate where we are going.In conclusion, the transition from physical to digital photo albums has reshaped our relationship with time and memory. While the format has changed, the underlying purpose of preserving and sharing our experiences remains constant. As we continue to navigate the digital landscape, it is essential to find a balance between the convenience of technology and the depth of our human experiences. By doing so, we canensure that our photo albums, in whatever form they take, continue to serve as a meaningful reflection of our lives and the passage of time.。
医学影像学专业英语Title: Advancements in Medical Imaging TechnologyMedical imaging is a pivotal field within the broader domain of healthcare, providing critical insights into the diagnosis, treatment, and management of diseases. Over the years, this field has witnessed remarkable advancements, transforming the way medical professionals approach patient care. This essay delves into the evolution of medical imaging technology, highlighting its significance in modern medicine and discussing future prospects.The journey of medical imaging began with simple X-rays in the late 19th century, which allowed for the visualization of bones and other dense structures within the body. This groundbreaking discovery laid the foundation for more sophisticated imaging techniques that followed. The development of computed tomography (CT) scans in the 1970s marked a significant milestone, enabling detailed cross-sectional images of the body's internal structures. CT scans revolutionized the diagnosis and monitoring of various conditions, from traumatic injuries to cancerous growths.Magnetic Resonance Imaging (MRI) further advanced the capabilities of medical imaging by utilizing powerful magnetsand radio waves to produce high-resolution images of soft tissues. Unlike X-rays and CT scans, MRI does not involve ionizing radiation, making it a safer option for repeated use and particularly beneficial for imaging the brain, spinal cord, and joints. The introduction of functional MRI (fMRI) expanded the scope of MRI by allowing doctors to observe brain activity and understand how different regions of the brain communicate with each other.Ultrasound imaging, another non-invasive technique, employs high-frequency sound waves to create real-time images of organs and tissues. Its portability, safety, andcost-effectiveness make ultrasound an indispensable tool in prenatal care, cardiovascular assessments, and guiding invasive procedures.Positron Emission Tomography (PET) scans represent yet another leap forward in medical imaging. By measuring metabolic processes, glucose metabolism, and blood flow within the body, PET scans are invaluable for detecting cancerous tissues, assessing treatment efficacy, and studying brain disorders such as Alzheimer's disease.The integration of artificial intelligence (AI) into medical imaging represents the latest frontier in this field. AIalgorithms can analyze vast amounts of imaging data rapidly and with high accuracy, assisting radiologists in identifying abnormalities that might be overlooked by the human eye. Moreover, AI-powered tools are being developed to predict disease progression and personalize treatment plans based on individual patient data.Despite these advancements, challenges remain. Ensuring equitable access to advanced imaging technologies across different populations and geographies is a significant concern. Additionally, the interpretation of complex imaging data requires highly trained professionals, underscoring the need for continuous education and training in medical imaging.Looking ahead, the future of medical imaging holds immense promise. Innovations such as molecular imaging, which targets specific biological processes at the cellular level, and photoacoustic imaging, which combines laser excitation with ultrasound detection, are poised to further enhance our understanding of disease mechanisms. As these technologies continue to evolve, they will undoubtedly play a crucial role in advancing personalized medicine and improving patient outcomes.In conclusion, the field of medical imaging has come along way since its inception, driven by continuous innovation and technological advancements. These developments have not only transformed diagnostic capabilities but also paved the way for new therapeutic approaches. As we look to the future, the integration of emerging technologies like AI promises to usher in a new era of precision medicine, ultimately leading to better health outcomes for patients worldwide.。
Interactive Evolution of ImagesJeanine Graf and Wolfgang BanzhafAbstractSystems of selection and variation by recombination and/or mutation can be used to evolve images for computer graphics and animation.Interactive evolution can be used to direct the development of favorite designs in various application areas.Examples of the application of evolutionary algorithms to two-dimensional(2-D)bitmap images and the methods for three-dimensional(3-D)voxel images are indicated.We show that artificial evolution can serve as a useful tool for achievingflexibility and complexity in image design with only a moderate amount of user-input and detailed knowledge.1INTRODUCTIONDawkins(Dawkins1986)demonstrated convincingly the potential of Dar-winian variation and selection in graphics.He evolved biomorphs2-D gra-phic objects,from a collection of genetic parameters with interaction with the user(Dawkins1986;Smith1984).Recently,much research has been directed into the application of genetic algorithms to image and graphics problems,such as the segmentation of range images(Meygret,Levine,and Roth1992)or pattern identification(Hill and Taylor1992).Sims(Sims1991) used genetic algorithms for interactive generation of color art;Todd and Latham(Todd and Latham1991)have considered similar ideas to reprodu-ce computer sculptures through structural geometric techniques.Caldwell and Johnson(Caldwell and Johnston1991)have applied the concept of ge-netic algorithms to search interactively in face space of criminal suspects with the help of witnesses.The novel idea offered in this paper is to provide a user with new technique to evolve2-D(bitmap)and3-D(voxel)images that can be applied universally in anyfield of interest.We have developed a system which presents progressively evolving solutions for graphical design problems by means of interactive processes.Interactive evolution is a technique from the class of evolutionary algo-rithms(EAs)which are based upon a simple model of organic evolution. Most of these algorithms operate on a population of individuals which re-present search points in the space of the decision variables(either directly,or by using coding mappings).Evolution proceeds from generation to gene-ration by exchanging genetic material between individuals(recombination), i.e.by trying out new combinations of partial solutions,and by random changes of individuals(mutation).New variations are subjected to selectionbased on an evaluation of features of the individuals according to certain (fitness)criteria.The best-known representatives of this class of algorithms are evolutio-nary programming(EP),developed in the U.S.by L.J.Fogel(Fogel,Owens, and Walsh1966),evolution strategies(ESs),developed in Germany by I. Rechenberg(Rechenberg1973)and H.–P.Schwefel(Schwefel1981),and genetic algorithms(GAs),developed in the U.S.by J.H.Holland(Holland 1975).Evolutionary programming(EP)tries to apply the variation-selection prin-ciple to ameliorate computer systems.The important and elementary steps of the search process are(i)a definition of the task and itsfitness criteria, (ii)creation of afirst representation,(iii)variation of the statement leading to offspring representations,(iv)performance qualification of the offspring representations,(v)reproduction of the best performing representations. The process is repeated until the task is accomplished(Fogel1993).Evolutionary programming uses real-valued object variables and normal-ly distributed random mutation with expectation zero.The variance of the distribution evolves during the optimization process.It is calculated se-parately for each representation as transformation of its ownfitness value. Mutation is the primary operator.Recombination is not used in the standard EP algorithm.Objective function values are scaled and possibly randomly altered to obtain thefitness.Selection of new parent representations is done probabilistically using a competition procedure which guarantees that the best representation is always retained and the worst always discarded.Thefirst applications of evolution strategies(ES)came in thefield of experimental optimization and used discrete mutations.When computers became available,algorithms were devised that operated with continuous-valued variables.The ES uses,like EP,mutation as its main search operator.In addition re-combination operators(e.g.discrete recombination)are applied.Parameters like the standard deviation of the mutation are added to the representation (individual)as strategy parameters,which are adapted during the simulation via heuristics like Rechenberg’s success rule(Rechenberg1973).Only the best individuals out of the offsprings or out of the offsprings and parents are selected to form the next population(Schwefel1981;B¨a ck1994; Rechenberg1973).The genetic algorithm(GA)works on a genotypic level of binary encoded individuals,a choice that is founded by the argument of maximizing the number of schemata available with respect to a given code(Goldberg1989; Davis1991).Various selection schemes,such as proportional selection,are applied with respect to the relativefitness of the individuals.The recombi-nation(e.g.,1-point crossover)serves as the main search operator.Mutation (e.g.,bit-mutation)is used at a low rate to maintain diversity.Nearly no knowledge about the properties of the object function is required.In order to use a GA for optimization,a mapping from the genotype(bitstring)to phenotype(realised behavior)has to be defined.This could be a very com-plicated task,because the mapping is absolutely crucial for the performance of the GA.In all of these cases,the selection criteria are traditionallyfixed and are held constant from the start of the simulation,therefore these criteria mustbe detailed explicitly beforehand.This constitutes a significant problem in many realistic applications(apart from optimization),because an explicit fitness function may not be available in closed form.Recently,various work-arounds have been tried,one of the most prominent being co-evolution. In this method,rather than using one population to search for the best solution,two or more antagonistic populations are run which compete against each other.The realizedfitness in this case is in part determined by the relationship of one population to the other,and does not have to be defined explicitly beforehand(Hillis1990).This paper makes use of an alternative method to generatefitness by involving the user into the selection process of artificial evolution.Our work in computer graphics,a natural domain for humans,easily engages the user by relying on human visual capacity.2INTERACTIVE EVOLUTIONIn interactive evolution,the user selects one or more favourite model(s)which survive(s)and reproduce(s)(with variation)to constitute a new generation. These techniques can be applied to the production of computer graphics, animation,creating forms,textures,and motions(Glassner1990;Arvo1991; Foley1992).Potential applications of interactive evolution include product design,e.g.,cars,engineering of components,and architectural design.Phenotypes and GenotypesWe shall need to discern between genotypes and phenotypes in interac-tive evolution,both terms are also basic concepts for biological evolution. The biological genotype is the information that codes the development of an individual.Genotypes most often consist of DNA sequences.In interactive evolution,genotypes are represented as numerical data and real values,col-lections of procedural parameters,symbolic expressions or compound data structures(e.g.,trees).The phenotype is the realised behavior of the indivi-dual itself,i.e.,the product of an interpretation of the underlying genotypic representation.In our case,the phenotype is the resulting graphical image.The relation between genotypes and phenotypes in nature is determined by the genotype-phenotype mapping.This transformation is very compli-cated and draws heavily from the individual’s current environment.In principle,a similar mapping can be introduced in artificial evolution(Banz-haf1994).In this way,a part of the complexity of the developing solution might be rendered by the environment.Fitness and SelectionThe termfitness in interactive evolution is the capability of an individu-al or model to survive into the next generation,and therefore is tied directly to ually,fitness is not defined explicitly but is instead a relative measure of success following from the selection activity of a human user. Here,it is even based on non-quantifiable measures like visual preference or personal taste.Hybrid systems,however,are reasonable as well.Certain predefinedcriteria(for example:drag coefficient()or air resistance of an airpla-ne model)help to sort candidates for survival from the set of all variants, among which a human userfinally selects the next generation.VariationIn interactive evolution,one of the main benefits is the automatic gene-ration of variants.Variation is accomplished by defining problem-specific mutation and recombination operators that constantly propose new vari-ants to the presently existing population of graphic models on the screen.A certain amount of knowledge has to be invested in order tofind appropriate operators for an application domain.In the next section we shall provide appropriate operators for manipulation of bitmap images and voxel gra-phics.Figure1:Generation of variants by recombination and mutation of graphical mo-dels.A*A and B*B are the unchanged parents,B*A and A*B are generated by recombination,and A’and B’are generated by mutation3EVOLVING2-D IMAGESIn our approach we try to evolve two-dimensional images specified either directly as bitmaps or as parameterized geometric models,such as those provided by vector graphics.Figure1gives a sketch of the variants that may arise from the graphical parent objects.Whereas the latter is more or less straight-forward in EAs,once the parameters have beenfixed,the former is a challenging task.To our knowledge no effort has been made to apply evolutionary algorithms to the evolution of bitmap images directly.Application to2-D ImagesBitmaps and other forms of direct encoding of images have found an excel-lent niche in computer graphics,video composition and image rendering (Foley1992;Kirik1992).Any2-D shape can be represented as a sequence ofpoints or vertices,with each vertex consisting of an ordered pair of numbers ,its coordinates.The array of pixel values of a2-D image,however, have nothing to do with the structure being represented in the image.This constitutes the challenge tofinding appropriate operators for the genera-tion of new variants of an existing image,because structural or functional conservation of the image content is of utmost importance in application.We solve the problem for realizing evolutionary operations by using warping and morphing to create variations.Warping is a method which,by using tiepoints in two images“A”and “B”,allows for the creation of intermediate images(Woldberg1990;Ru-precht1994).Basically,these intermediate images are interpolations along an abstract axis from image“A”and image“B”.The tiepoints are cons-traints of the interpolation because corresponding tiepoints in“A”have to be transformed into those of“B”.Morphing is an application of digital image warping.It involves dis-tributing tiepoints over two images in such a way as to conserve essential structures in interpolated(intermediate)images.In this way an arbitrary initial image can evolve via intermediate steps of interpolation into afinal image without leaving visual irritations.It is interesting to note that even without any concept of structure in image warping and morphing,visually appealing images are generated. Structure has been substituted by tiepoints that extend their influence into the surrounding image by the help of interpolation algorithms.We adopt this novel approach for the artificial evolution of images.By specifying tiepoints,sufficient control can be exerted about structure in2-D images as to provide useful variants to the images being varied.Whereas in conventional computer graphics morphing is used for the purpose of transforming images in a dynamic animation series,we use the generated intermediate images as variants of the original images in the process of evolution.Let us look more closely at the operations usually implemented in EAs: Mutation is commonly considered to be a local operation that does not radically change the resulting phenotype.In order to provide this feature in bitmap image evolution,we propose to use a very small number of tiepoints.A one-point mutation would select one tiepoint in an image.The corresponding tiepoint in a second image would then be used as a source for novelty,by providing information into which direction to evolve the original image.Structure is conserved because tiepoints in both images correspond to each other.A parameter would then be used to quantify the degree of substitution in the image.Note that the second image,from which novelty is gained,is not ne-cessarily in the present generation of the evolutionary process.Instead,a generation0of images,equipped with a number of tiepoints is used for mutation.By selecting one tiepoint in an image of generation n that corre-sponds to a tiepoint in an image of generation0and constraining the effect to a local neighborhood,we provide a path for morphing between the two images.The generation0images in a way help to form equivalence classes between structures expressed as tiepoints.Some domain knowledge must be used in the process of tiepoint selection for generation0.Figure2:Thisfigure shows an example recombination of two bitmap images through image interpolation.The percentage represents the proportion of inheritance fromthe parent imagesRecombination is implemented as a more global operation by which two images exchange information.We propose to use as many tiepoints as necessary to conserve the underlying structure in two images“A”and“B”.A recombination would then be quantified in the image space between“A”and“B”by a certain parameter indicating the degree of“intermediateness”of a variant.Figure2demonstrates the method of recombination.Different variants between the two original cars are shown.Note that recombination always operates within the present generation.Figure3and4demonstrates the mutation process by using2-D images of cars.A local variation takes place by substituting one sort of wheel by another(Figure3).Figure3:Local mutation by substituting one wheel by another.Figure4:Whole mutation of a car by slightly random warping.An arbitrary warping of an image at different locations,without using the proper equivalence class of image structures is shown in a contrasting image in Figure4.It gives the impression of a damaged car.That is the case because arbitrary operations have been applied without being constrained by an otherwise existing path of variation between structures.First generationThird generationFifth generationFigure5:This example shows the evolution of nine models.Afterfive generations some models are found which are closer to the users taste and to his target model.Structurally,the content of an image is usually composed of components. In our example,a car is composed of a body,wheels,seats,chassis,engine, windows and doors.The same method that was applied before to the entire image representing the whole structure can also be applied to its components.By using many tiepoints in a component such as,say a wheel, influence can be exerted to any necessary degree about the details of the evolving structure.Before presenting the entire interactive evolution system,we now turn to other representations of images.Application to2-D structural descriptions of imagesProcedural models of images can be characterized by certain parameters that must be interpreted in the appropriate context.The parameters consti-tute the genotype of an image.Its interpretation is the genotype-phenotype mapping and the resulting image is the phenotype.Because the number of structural elements usually varies from image to image,it is necessary to allow for variable-length genotypes.Variation takes place on the level of parameters that are subjected to nor-mally distributed random mutations as well as to intermediate or discrete recombination operations.The resulting images are subjected to the same selection procedures as are those of the bitmap manipulation procedures discussed before.4EVOLVING3-D IMAGESFor various applications in computer graphics it is often useful to represent objects in a3-D grid of cubes or voxels(volume elements)according to their position in space(Young and Pew1992).Figure6:3-D mutationFrom objects in3-D space an image can be constructed using establis-hed methods of computer graphics(Watt1993).Alternatively,procedural models of3-D objects can be combined into an image.The generalisation of the above methods into the realm of3-D graphics is straight-forward.Tiepoints in3-D voxel graphics influence3-D areas instead of2-D areas in pixel graphics.Apart from that,any other compo-nent of the mechanism remains in place,especially interpolation and the generation of local and global variation to an original parent generation of images.The same applies to procedural models that are generated by applying a genotype-phenotype mapping starting from a collection of appropriate parameters.Figure5and6show two examples of3-D mutations that can be used.Figure7:Mutation through deformation[26].A set of transformations that deform the object.Linear transformation rotate,translate or scale the object.5JARDIN–A SYSTEM FOR INTERACTIVE EVOLUTIONJardin is a digital image warping and morphing program,that allows the evolution of images,and runs under the X Window System(Cutler,Gilly, and O‘Reilly1993;Gaskin1992;Young and Pew1992).Jardin loads and saves image populations.It provides facilities to store tiepoints in images, to warp images and to apply the evolutionary process.Tiepoints are inhe-rited from generation to generation,with generation“0”provided by the user.With a very small population,between2and20graphical models per generation and over a short time,a human user can select new generations of images.This process will be repeated until a favourite individual in the population has been generated.6SUMMARY AND CONCLUSIONSWe demonstrate how interactive evolution can be applied to2-D bitmap images and a generalization to3-D representation is outlined.The main idea is to combine the concepts from interactive evolutionary algorithms with the concepts of warping and morphing from computer graphics.Structure within images is substituted by a collection of tiepoints.By providing a first generation of images,where a structure in the images can manually be defined by the user.Evolution then proceeds along the paths constrained by the set of these tiepoints in all of the images.The original generation is kept as a source for mutations,which allows for new models to be created.In contrast recombination always works on images of the present generation.In our version of interactive evolution,the user selects his favourite indi-vidual which then is reproduced to constitute the next generation.These techniques can be applied to the production of computer graphics and in-clude e.g.,product visualisation of cars,planes,engineering components and construction projects.Our interactive evolution system has the poten-tial for a large number of other application areas like:interactive plotting in business,electronic publishing,computer aided design,drafting and manufacturing,simulation and animation for scientific visualisation,enter-tainment,architecture,etc.Our interactive simulations have shown that interesting results can be achieved even with low population sizes and few generations.This makes the system applicable to quick design and proto-typing,in a large variety of application areas.AcknowledgementsFunding from the German Bundesministerium f¨ur Forschung und Techno-logie(BMFT)under project EVOALG is gratefully acknowledged.Thanks to Detlef Ruprecht for help and morphing graphics software support.Thanks to Thomas B¨a ck for discussions.And special thanks to David 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