SK1 to PGM Converter

Free online SK1 to PGM converter — grayscale bitmap

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Grayscale Precision

PGM captures tonal variations from your SK1 design in a clean grayscale format — ideal for analysis and Unix-based processing.

Rapid Results

Cloud servers convert your SK1 to PGM in seconds. No queuing, no local computation, no software to install.

Automatic Cleanup

Source SK1 files are removed after conversion. PGM downloads are purged from Convertio servers within 24 hours.

How to convert SK1 to PGM

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose pgm or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your pgm file right afterwards

About formats

SK1 is the native file format of the sK1 project, an open-source vector graphics editor and conversion engine started by Igor Novikov in 2003 as a successor to Bernhard Herzog's Skencil. The format evolved from the original SK format, extending its capabilities while maintaining the text-based, Python-readable syntax for describing vector documents. SK1 files encode complete document structures including multiple pages, layers, guidelines, and a full hierarchy of graphic objects — Bezier paths, rectangles, circles, polygons, text blocks, and embedded raster images — with attributes for fills (solid, gradient, pattern, hatching), strokes, and transformations. The sK1 project distinguished itself by focusing on prepress and professional print production features, adding CMYK color management, ICC color profiles, spot color support, and PDF/PostScript output — capabilities unusual in open-source vector editors. One advantage is professional color handling — sK1's CMYK workflows and color management make it one of the few open-source tools suitable for print-ready vector production. The project's companion tool, UniConvertor, leverages the SK1 format as an intermediate representation for converting between numerous vector formats (CDR, CMX, WMF, EMF, SVG, and others), giving SK1 significance beyond the editor itself as a universal interchange format. The text-based file structure preserves the readability and scriptability advantages inherited from Skencil's original SK format.
Initial release: 2003
PGM (Portable Graymap) is the grayscale member of the Netpbm image format family, created by Jef Poskanzer in 1988 as part of the Pbmplus toolkit for Unix systems. PGM stores single-channel intensity images where each pixel holds a gray value from 0 (black) to a user-specified maximum (typically 255 for 8-bit or 65535 for 16-bit). The format exists in ASCII (magic number P2), where pixel values are written as decimal text numbers separated by whitespace, and binary (magic number P5), where values are stored as raw bytes. Both variants begin with a header specifying the magic number, width, height, and maximum gray value. PGM was designed as the grayscale intermediate in Netpbm's convert-process-convert pipeline philosophy: source images from any format are converted to PGM, processed using Netpbm's extensive command-line tool library, then converted to the target format. One advantage is format transparency — the ASCII variant makes image data directly readable by humans and trivially processable by text tools like awk and grep, invaluable for debugging and education. The scientific and computer vision community's adoption is another strength: PGM's straightforward single-channel representation makes it a natural format for image analysis algorithms, and many academic papers and course materials use PGM examples. The format is supported by ImageMagick, GIMP, and countless image processing libraries, and remains standard input for many research tools and benchmarks.
Developer: Jef Poskanzer
Initial release: 1988

Frequently Asked Questions

Why convert SK1 to PGM?

PGM is a grayscale bitmap format used in image analysis and Unix tools. Converting SK1 to PGM creates a clean grayscale raster from your vectors.

What opens PGM files?

PGM opens in GIMP, IrfanView, XnView, Netpbm utilities, and most image processing applications on Linux and Unix systems.

Is PGM different from PBM?

PBM is monochrome (1-bit), while PGM supports grayscale with multiple levels. PGM preserves tonal variations from your SK1 artwork.

Is the conversion free?

Free conversion is available at Convertio for all users. Premium options exist for larger files and higher daily conversion volumes.

Can PGM be used in scientific imaging?

Yes — PGM is common in scientific and medical imaging pipelines due to its simple, well-documented structure.