DJVU to PNG Converter

DjVu is a raster image file format developed by researchers at AT&T Labs (including Yann LeCun) specifically for storing high-resolution scanned documents. It employs a content-specific compression algorithm that separates images into three layers: background (paper texture), foreground (text/line art), and a bi-level mask (JB2 compression), enabling high compression ratios superior to PDF or TIFF. The format utilizes arithmetic coding (ZM-coder) and wavelet-based compression (IW44) to deliver legible text rendering at low bitrates.

Most operating systems do not include native kernel support for DjVu rendering. To open these files, users require specialized viewers such as DjView4, WinDjView (Windows), or MacDjView (macOS). Multi-format image viewers like IrfanView (with plugins) and XnView also support the format. For browser-based access, specific plugin implementations or conversion to PDF are often required as modern browsers do not render DjVu natively.

Portable Network Graphics (PNG) is a raster graphics file format that supports lossless data compression, created as a patent-free replacement for the Graphics Interchange Format (GIF). Standardized as ISO/IEC 15948:2004, PNG utilizes the DEFLATE compression algorithm (a combination of LZ77 and Huffman coding) and supports palette-based images, grayscale, and full-color non-palette-based RGB/RGBA images. A defining feature is its alpha channel support, allowing for variable transparency levels, unlike the binary transparency of GIF. It does not support animation but offers gamma correction and interlacing via the Adam7 algorithm.

PNG files possess near-universal compatibility across all major operating systems (Windows, macOS, Linux, Android, iOS) and web browsers (Chrome, Firefox, Safari) without requiring additional software. Default image viewers such as Microsoft Photos, Apple Preview, and virtually all graphics editing software including GIMP, Adobe Photoshop, and Paint.NET natively handle the format.