---
id: css-image-effects
title: "CSS Image Effects"
category: "Frontend"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["image opacity", "image transparency", "text on image", "image text positioning", "image effects"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.85
created_at: 2026-06-23
updated_at: 2026-06-23
review_reason: ""
merge_history: []
tags: ["css", "web", "frontend", "w3schools", "images", "opacity"]
raw_sources: ["https://www.w3schools.com/css/css3_images_effects.asp"]
applied_in: []
github_commit: ""
---

# [[CSS Image Effects]]

## 🎯 한 줄 통찰 (One-line insight)
The W3Schools "CSS Image Effects" page covers two effects: making images transparent with the `opacity` property, and overlaying text on an image positioned at the corners or center. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Image opacity** — the `opacity` property controls how transparent an image is, taking values from `0.0` (fully transparent) to `1.0` (fully opaque). [S1]
- **Partial transparency** — values between, such as `0.5`, render the image partially see-through. [S1]
- **Text on an image** — text can be overlaid on an image and positioned at the top left, top right, bottom left, bottom right, or centered. [S1]

## 🧩 추출된 패턴 (Extracted patterns)
- **Opacity as a 0–1 dial** — transparency is a single continuous value where lower means more see-through, useful for hover dimming or watermark effects. [S1]
- **Corner-anchored overlay** — positioning text over an image relies on a positioned container with the text element placed against a chosen corner or centered. [S1]

## 📖 세부 내용 (Details)
**Image opacity / transparency**
The `opacity` property specifies the transparency of an image. It accepts a value from `0.0` to `1.0`: the lower the value, the more transparent the image. A value of `0.0` makes the image fully transparent, an intermediate value such as `0.5` makes it partially transparent, and `1.0` is the default (fully opaque). [S1]

**Image text positioning**
Text can be placed on top of an image and positioned in different spots: top left, top right, bottom left, bottom right, or centered. The fetched content describes these positioning options but does not include the inline CSS declaration blocks for each placement — those appear only behind the page's "Try it Yourself" examples. The exact per-position CSS is "Not found in source". [S1]

> Note: The page title "CSS Image Effects" on W3Schools does NOT cover image reflection (`box-reflect`). The fetched content confirms the page is limited to image opacity/transparency and image text positioning. [S1]

## 🛠️ 적용 사례 (Applied in summary)
The source's applied cases are the opacity-based transparency demos (full, partial, and full opacity) and the text-over-image positioning demos. No external project/commit applications found in the source.

## 💻 코드 패턴 (Code patterns)
Image transparency dial (language: CSS):
```css
img {
  opacity: 0.5;
}
```

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
No contradictions found in the source. Note that the per-corner text-positioning CSS was not present inline in the fetched content (marked "Not found in source" above).

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual (실제 적용 사례 발견 시 applied/validated로 승격 가능)
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.85
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[CSS Tutorial]]
- **관련 개념:** [[CSS Image Hover]], [[CSS Image Filters]], [[CSS Image Styling]], [[CSS Position]]
- **참조 맥락:** Referenced when dimming images via opacity or labeling images with overlaid text.

## 📚 출처 (Sources)
- [S1] W3Schools — CSS Image Effects — https://www.w3schools.com/css/css3_images_effects.asp

## 📝 변경 이력 (Change history)
- 2026-06-23: Initial draft synthesized from the W3Schools "CSS Image Effects" page (Astra wiki-curation, P-Reinforce v3.1 format).
