What is JPG/JPEG?
JPEG is a commonly used method of lossy compression for digital images, particularly for photographs. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality.
The format is the result of work by the Joint Photographic Experts Group, formed in 1986. JPEG compression is used in many image file formats and is the most common format for storing and transmitting photographic images on the World Wide Web.
History
The JPEG standard was created in 1986 by the Joint Photographic Experts Group committee. The first JPEG standard was issued in 1992 as ISO/IEC IS 10918-1.
- 1986: JPEG committee formed
- 1992: JPEG standard officially released
- 1994: JFIF standardized
- 2000: JPEG 2000 released
Key Features
- Lossy Compression: Adjustable quality levels
- 24-bit Color: 16.7 million colors
- Universal Support: All browsers and devices
- Small Files: Ideal for web use
- Progressive Encoding: Faster loading
- EXIF Metadata: Camera information support
Common Uses
- Digital photography
- Website images
- Social media posts
- Email attachments
- Online galleries
- Print materials
Advantages
- Excellent compression for photos
- Universal compatibility
- Small file sizes
- Adjustable quality
- Wide software support
Limitations
- Quality loss with compression
- No transparency support
- Not ideal for text or line art
- Quality degrades with each save
- Artifacts in flat-color areas
Technical Information
JPEG uses Discrete Cosine Transform (DCT) to convert spatial image data into frequency data, allowing the algorithm to discard high-frequency information less visible to the human eye.
| File extension | .jpg, .jpeg |
| MIME type | image/jpeg |
| Developed by | Joint Photographic Experts Group |
| First released | 1992 |
| Compression | Lossy (DCT-based) |
| Color depth | 24-bit (16.7M colors) |
| Transparency | Not supported |