Unleashing the Spell of AI Art: Prompt Engineering for Creators to Generate Desired Images - CLT Earth

The Dawn of AI Image Generation: The Power of ‘Spells’ to Manifest Imagination

The act of ‘creating art,’ once reserved for professional artists, expensive software, and immense time and skill, can now be achieved simply by typing text. AI image generation technology has fundamentally reshaped the possibilities of our creative expression, opening new horizons in art. At the heart of this revolution lies the text we call ‘prompts’ – the ‘spell’ or ‘incantation’ that brings visuals to life.

A prompt is an ‘instruction manual’ for the AI, telling it what and how to draw. Its precision and expressiveness are key to transforming your vague mental images into breathtaking visual art. However, simply listing words won’t allow the AI to accurately grasp your intentions. Just as a wizard must cast precise spells, prompts require a specific structure, keywords, and ‘tricks.’

As a technology writer deeply immersed in the forefront of ‘Cyber・Life・Tech,’ this article will thoroughly explain the ‘spells’ of AI image generation – prompt writing. From fundamental knowledge to advanced techniques, practical case studies, and actionable advice, reading this will empower you to become a true AI art creator, capable of generating images exactly as you envision them.

Basic Knowledge of Prompts: The First Step in Dialogue with AI

An AI image generation prompt is a text instruction given to an AI model. By interpreting this instruction, the AI extracts relevant elements from its vast training data and generates a new image. This process is often based on a technology called ‘Diffusion Models,’ which iteratively generates an image by gradually removing noise.

Key Components of a Prompt

Subject: What to draw. People, animals, objects, landscapes. E.g., “a beautiful woman,” “a wolf in the forest,” “an ancient castle.”
Action/Pose: What the subject is doing or its posture. E.g., “running,” “sitting,” “holding a sword,” “meditating.”
Environment/Setting: Where and in what context. E.g., “a futuristic city at night,” “deep in a forest,” “outer space,” “a ruined building.”
Style/Genre: The artistic style or atmosphere. E.g., “oil painting,” “anime style,” “cyberpunk,” “watercolor,” “photorealistic.”
Lighting: How light is expressed. E.g., “golden hour light,” “neon lights,” “backlight,” “dramatic lighting,” “soft light.”
Composition/Camera Angle: How the scene is framed. E.g., “close-up shot,” “wide shot,” “bird’s eye view,” “portrait,” “full body shot.”
Quality/Resolution: Instructions regarding image quality. E.g., “best quality,” “ultra detailed,” “8K,” “high resolution,” “photo realistic.”
Additional Details: More specific information like color, texture, emotion. E.g., “red and blue,” “metallic texture,” “sad expression,” “mist.”

By combining these elements, the AI can generate images that are more specific and closer to your intentions.

Detailed Explanation: Mastering the Art of Prompt Engineering

1. Basic Prompt Construction: From Simple to Complex

It’s effective to start a prompt with the core elements and gradually add details. AI tends to prioritize words at the beginning of the prompt and those that are more specific or emphasized.

Tips for Keyword Selection: Choose specific words over abstract ones. Instead of “flower,” use “a bouquet of blooming roses”; instead of “building,” use “a Gothic cathedral.” The more specific you are, the better the AI will grasp the image.
Importance of Order: Place the most emphasized elements at the beginning of the prompt. For example, in “A beautiful woman, wearing futuristic armor, in a cyberpunk city” versus “A cyberpunk city, with a beautiful woman wearing futuristic armor,” the former tends to focus on the woman, while the latter focuses on the city.
Punctuation and Separators: Commas (,) are useful for separating different elements. In many AI models, words or phrases separated by commas are more likely to be interpreted as distinct instructions.
Parentheses and Weighting: To emphasize specific keywords, you can use weighting syntax with parentheses (()) or colons (:). For instance, (cyberpunk city:1.2) can make the “cyberpunk city” element 1.2 times stronger. (Syntax varies by model).

2. Specifying Style and Expression: Commanding Artistic Diversity

One of the great pleasures of AI image generation is the freedom to experiment with various artistic styles. Specifying concrete styles or artist names can dramatically alter the mood of your work.

Art Movements: “Impressionism,” “Surrealism,” “Baroque,” “Ukiyo-e,” etc.
Artist Names: To emulate the style of a particular painter. E.g., “by Vincent van Gogh,” “Art by Greg Rutkowski,” “Studio Ghibli style.”
Mediums/Materials: “Oil painting,” “Watercolor,” “Digital art,” “Photography,” “Pencil sketch,” etc.
Rendering Styles: “Photorealistic,” “Anime style,” “Pixel art,” “Low poly,” “Isometric,” etc.

By combining these keywords, you can achieve highly specific expressions, such as “A lonely samurai, in the style of Ukiyo-e, by Hokusai.”

3. Controlling Light, Shadow, and Composition: Adding Photographic Depth

Light, shadow, and composition are crucial elements that determine an image’s atmosphere and message. By specifying these in your prompt, you can create the depth and drama found in professional photographs and paintings.

Types of Lighting: “Golden hour,” “Volumetric lighting (god rays),” “Rim light,” “Studio lighting,” “Cinematic lighting,” “Neon light,” “Dramatic lighting,” etc.
Camera Angles and Composition: “Close-up shot,” “Wide shot,” “Bird's eye view,” “Worm's eye view,” “Portrait,” “Full body shot,” “Rule of thirds,” “Leading lines,” etc.
Depth of Field: Specifying “Shallow depth of field” or “Bokeh” can make the subject stand out and blur the background.

4. Utilizing Negative Prompts: The ‘Spell’ to Exclude Unwanted Elements

Just as important as positive prompts (elements you want to generate) are negative prompts (elements you want to avoid). These are used to exclude unintended or undesirable elements from the image generated by the AI.

Why Negative Prompts Are Necessary: While AI is highly creative, it can sometimes misunderstand our intentions or reproduce undesirable features present in its training data. For example, unnatural fingers on a person or low image quality.
Common Negative Prompts: “ugly,” “deformed,” “blurry,” “low quality,” “bad anatomy,” “extra limbs,” “missing limbs,” “text,” “watermark,” “signature,” etc.
Advanced Negative Prompts: For excluding specific unwanted objects or styles. E.g., “disfigured faces,” “poorly drawn hands,” “monochrome.”

Negative prompts are powerful tools that dramatically improve the quality and accuracy of generated images. Many AI image generation tools provide a dedicated input field for negative prompts.

5. Weighting and Emphasis: Controlling AI’s Attention

As mentioned, many AI models allow you to adjust the degree to which certain words or phrases in a prompt are reflected by assigning them a ‘weight.’ This is an advanced technique for drawing the AI’s attention to specific details.

Syntax Examples: In Stable Diffusion-based models, weighting is done using a colon and a number, like (keyword:1.2). A larger number emphasizes it more, while a number below 1.0 reduces emphasis. In Midjourney, two colons followed by a number, like keyword::2, are used for weighting.
Iterative Adjustment: It’s effective to start generating with default weights, then gradually adjust the weights for elements you want to emphasize or de-emphasize. This is useful, for example, when you want to strengthen the depiction of a specific color or highlight certain details of clothing.

6. Seed Value and Iteration: Controlling Randomness

AI image generation internally generates images based on a random ‘seed value.’ By fixing this seed value, you can consistently reproduce the same image from the same prompt. You can also explore subtle variations by slightly changing the seed value.

Reproducibility: If you generate an image you like, recording its seed value allows you to regenerate the same image later or generate variations by fine-tuning the prompt based on that image.
Exploratory Generation: By fixing the seed value and changing one word at a time in the prompt, you can experimentally discover how each word affects the image. This is extremely helpful for learning prompt engineering.

7. Choosing Models and Samplers: Understanding AI Personalities

There are various AI image generation models, such as Stable Diffusion, Midjourney, and DALL-E 3, each with its own strengths in style and interpretation tendencies. Additionally, ‘samplers,’ which are internal image generation algorithms, also influence the texture and detail of the generated images.

Model Characteristics:
- Midjourney: Excels at generating artistic and fantastical images. It has a distinctive aesthetic and is particularly suitable for illustrations and concept art.
- Stable Diffusion: Highly versatile, capable of handling a wide range of styles from realistic photos to anime and illustrations. Being open-source, many derivative and custom models exist, offering high extensibility.
- DALL-E 3: Known for its high prompt comprehension, excelling in complex instructions and text depiction.
Sampler Types: Various samplers exist, such as Euler, DPM++ 2M Karras, DDIM, and LMS. Each differs in generation speed, image smoothness, and detail expression. Generally, DPM++ 2M Karras is known to produce high-quality images, but it’s crucial to experiment and find the sampler that best suits your preferences.

Case Study: From Idea to Masterpiece – Creating a Futuristic City

Let’s walk through the prompt engineering process with a concrete scenario: generating an “anime-style painting of a cyberpunk futuristic city at night, with neon lights glowing and flying cars in the sky.“

Step 1: Presenting the Core Idea (Simple Prompt)

First, we convey the most basic elements.

Prompt: cyberpunk city at night, flying cars
Expected Outcome: A cyberpunk city night scene with flying cars, but lacking specific details or style.

Step 2: Adding Style and Atmosphere

Next, we specify the artistic style and atmosphere to define the direction.

Prompt: cyberpunk city at night, flying cars, neon lights, anime style, highly detailed, vibrant colors
Expected Outcome: The image takes on an anime style, with neon lights and vibrant colors. However, it still lacks depth.

Step 3: Creating Drama with Lighting and Composition

Further, we add lighting and camera angles to enhance the image’s dramatic quality.

Prompt: A vast cyberpunk city at night, flying cars in the sky, glowing neon lights reflecting on wet streets, anime style, highly detailed, vibrant colors, cinematic lighting, wide shot, volumetric fog, rain
Expected Outcome: A sprawling nightscape of the city, with neon reflections on wet streets, and cinematic lighting and fog, creating a more immersive scene.

Step 4: Emphasizing Quality and Detail, and Negative Prompts

Finally, we maximize image quality and exclude unwanted elements. Weighting is also adjusted here.

Prompt: (A vast cyberpunk city:1.2) at night, flying cars in the sky, (glowing neon lights reflecting on wet streets:1.1), anime style, (masterpiece:1.3), (best quality:1.3), (ultra detailed:1.2), vibrant colors, cinematic lighting, wide shot, volumetric fog, rain
Negative Prompt: ugly, deformed, blurry, low quality, bad anatomy, extra limbs, text, watermark, signature, monochrome, grayscale
Expected Outcome: A high-quality, detailed, and atmospheric cyberpunk city night scene, closest to the ideal. Common AI generation flaws are eliminated by the negative prompts.

Through this process, you can see how a simple list of keywords evolves into a concrete ‘spell’ that reflects intention and creativity.

Merits and Demerits of Prompt Engineering

Merits

Infinite Creativity: The barrier to shaping imagination is dramatically lowered, allowing for the realization of unprecedented ideas and visions.
Rapid Prototyping: Generate a vast quantity of diverse designs and concepts in a short time, accelerating the iteration cycle.
Cost-Effectiveness: Generate high-quality images at a significantly lower cost than commissioning professional artists.
Democratization of Art: People without drawing skills can create art through text, giving everyone a chance to be a creator.
Exploration of New Forms of Expression: Through collaboration with AI, there’s potential to discover new artistic styles and methods of expression that humans alone might not conceive.

Demerits

Steep Learning Curve: Effective prompt creation requires a certain level of learning and experience with AI model characteristics, prompt syntax, and keyword selection.
Ethical and Copyright Issues: There are active ethical and legal debates surrounding mimicking specific artist styles or generating images similar to existing works.
“Black Box” Problem: The internal process of why AI generates a particular image is often unclear, making it difficult to achieve perfectly intended results.
Model Bias: If the dataset an AI learns from is biased, generated images may reflect stereotypes or prejudices.
Over-reliance: Excessive reliance on AI could potentially diminish traditional human artistic skills and creativity.
Need for Continuous Knowledge Updates: AI technology evolves daily, with new models and features constantly emerging. Continuous learning of the latest information is necessary.

Frequently Asked Questions (FAQ)

Q1: What is the most important thing for writing good prompts?

A1: The most important aspects are “specificity” and “iterative experimentation.” Choose concrete words that appeal to the five senses rather than vague expressions, and describe details thoroughly. Also, it’s rare to get a perfect prompt on the first try, so a process of repeated trial and error, adjusting the prompt based on the results, is essential.

Q2: How long should a prompt be?

A2: Longer is not necessarily better. The key is whether “the necessary information is included without being excessive or insufficient.” It’s good to start short and gradually add details. Including too much information can confuse the AI or emphasize unintended elements. A general guideline is to cover the main elements within about 100 words.

Q3: Is it ethically problematic to mimic the style of a specific artist?

A3: This is currently a highly debated area, and clear legal or ethical consensus has not yet been reached. For commercial use, the prevailing opinion suggests avoiding direct use of specific artist names in prompts to mitigate copyright infringement risks. While it’s often not an issue for personal hobby use, the fundamental question of who is the “creator” of AI-generated art should always be considered.

Q4: What should I do if my prompt isn’t working?

A4: There are several approaches. First, try changing the order of your prompt or adjusting weights. Next, try making your keywords more specific, or conversely, slightly more abstract. Strengthening your negative prompts to actively exclude unwanted elements is also effective. Experimenting with different AI models or samplers can also be beneficial. Most importantly, don’t give up after one failure; try different approaches repeatedly.

Q5: Should I write prompts in Japanese or English?

A5: Most current AI image generation models are trained on English data, so writing prompts in English tends to yield more accurate and diverse results. While Japanese prompts are supported, the interpretation accuracy might be lower compared to English. If possible, it is recommended to create prompts in English. However, models specialized in Japanese are also being developed, so this situation may change in the future.

Conclusion: Towards a Future of Creation with AI

The ‘spell’ of AI image generation, the prompt, is more than just text. It is the key, the language, to unleash our inner imagination into the real world through the powerful tool of AI. Drawing inspiration from the fundamental knowledge, detailed techniques, and practical case studies presented in this article, we encourage you to become a master of prompt engineering and experience the joy of generating images exactly as you envision them.

AI technology is evolving daily, and the possibilities of prompts are endlessly expanding. Do not be afraid to experiment with various keywords and syntaxes, and continue to pursue your own creative expression through dialogue with AI. The art born from the collaboration between humans and AI will undoubtedly lead us to a new world of wonder and inspiration. The future of creativity begins with your ‘spell.’

#AI Art #Prompt Engineering #Image Generation #Creative Tech #Stable Diffusion #Midjourney #DALL-E #Digital Art