Overview

ISO/IEC 15948:2004 specifies the Portable Network Graphics (PNG) datastream and associated file format for a lossless, portable, compressed computer graphics image intended for transmission across the Internet. The standard (ISO/IEC 15948:2004) defines the PNG functional specification and the Internet media type image/png. PNG supports indexed-colour, greyscale, and truecolour images with optional transparency, broad sample depth ranges, streaming and progressive display, and embedded colour-management data for accurate rendering across platforms.

Key Topics and Technical Requirements

Lossless compression for individual images to preserve original pixel data.
Supported image types: indexed-colour, greyscale, and truecolour.
Transparency: optional alpha/transparency support for overlays and compositing.
Sample depths: range from 1 to 16 bits per sample to accommodate low- and high-precision images.
Streamability and progressive display: fully streamable datastream with an option for progressive rendering during transmission.
Robustness and integrity: mechanisms for full file integrity checking and simple detection of common transmission errors.
Colour management: ability to store gamma, chromaticity data and a full ICC colour profile for cross-platform colour matching.
Media type registration: defines the Internet Media type image/png, facilitating consistent handling by web and network software.

Applications

ISO/IEC 15948:2004 (the PNG specification) is widely applicable where lossless, portable images are required:

Web graphics (icons, logos, screenshots) that require sharp edges and transparency.
User-interface assets and application graphics needing exact pixel fidelity.
Image exchange between heterogeneous systems where consistent colour reproduction matters (uses embedded ICC profiles, gamma, chromaticity).
Archival and documentation scenarios where integrity checking and lossless storage are important.
Streaming or progressive delivery contexts (content delivery networks, web clients) that benefit from incremental display.

Who Uses This Standard

Software developers and library authors implementing image encoders/decoders and viewers.
Web and front-end developers choosing image formats for sites and apps.
Browser and OS vendors ensuring consistent PNG rendering.
Digital asset managers, archivists, and imaging professionals requiring lossless preservation and colour fidelity.
Standards bodies and implementers registering or handling the image/png media type.

Related Standards

The standard explicitly defines the image/png Internet Media Type used in web and networking contexts.
PNG is commonly considered alongside other raster image standards (e.g., JPEG, GIF) when selecting image formats for quality, transparency, and compression trade-offs.

Keywords: ISO/IEC 15948:2004, PNG specification, Portable Network Graphics, image/png, lossless compression, ICC colour profile, transparency, progressive display.

Overview

Key Topics and Technical Requirements

Lossless compression for individual images to preserve original pixel data.
Supported image types: indexed-colour, greyscale, and truecolour.
Transparency: optional alpha/transparency support for overlays and compositing.
Sample depths: range from 1 to 16 bits per sample to accommodate low- and high-precision images.
Streamability and progressive display: fully streamable datastream with an option for progressive rendering during transmission.
Robustness and integrity: mechanisms for full file integrity checking and simple detection of common transmission errors.
Colour management: ability to store gamma, chromaticity data and a full ICC colour profile for cross-platform colour matching.
Media type registration: defines the Internet Media type image/png, facilitating consistent handling by web and network software.

Applications

ISO/IEC 15948:2004 (the PNG specification) is widely applicable where lossless, portable images are required:

Web graphics (icons, logos, screenshots) that require sharp edges and transparency.
User-interface assets and application graphics needing exact pixel fidelity.
Image exchange between heterogeneous systems where consistent colour reproduction matters (uses embedded ICC profiles, gamma, chromaticity).
Archival and documentation scenarios where integrity checking and lossless storage are important.
Streaming or progressive delivery contexts (content delivery networks, web clients) that benefit from incremental display.

Who Uses This Standard

Software developers and library authors implementing image encoders/decoders and viewers.
Web and front-end developers choosing image formats for sites and apps.
Browser and OS vendors ensuring consistent PNG rendering.
Digital asset managers, archivists, and imaging professionals requiring lossless preservation and colour fidelity.
Standards bodies and implementers registering or handling the image/png media type.

Related Standards

The standard explicitly defines the image/png Internet Media Type used in web and networking contexts.
PNG is commonly considered alongside other raster image standards (e.g., JPEG, GIF) when selecting image formats for quality, transparency, and compression trade-offs.

Keywords: ISO/IEC 15948:2004, PNG specification, Portable Network Graphics, image/png, lossless compression, ICC colour profile, transparency, progressive display.

ISO/IEC 15948:2004 PDF

Technical details

Abstract

Overview

Key Topics and Technical Requirements

Applications

Who Uses This Standard

Related Standards

Related standards

Abstract

Overview

Key Topics and Technical Requirements

Applications

Who Uses This Standard

Related Standards

Related standards

Systems and software engineering — Software life cycle processes

Asset management — Vocabulary, overview and principles

Asset management — Asset management system — Requirements

Information technology — Radio frequency identification device conformance test methods — Part 2: Test method…

Information technology — Multimedia framework (MPEG-21) — Part 22: User Description

Milk — Determination of the lactoperoxidase activity — Photometric method (Reference method)

Carbonaceous materials for the production of aluminium — Cold and tepid ramming pastes — Expansion/shrinkage…

Agricultural machinery — Safety — Part 13: Large rotary mowers