photomosaic

photomosaic is a free, open-source Python package that builds a large image from a collection of smaller tile images. Its layouts can mix tile sizes and place them irregularly or with overlap. It can use smaller tiles in detailed regions, and a mask can guide tile placement to roughly follow an edge. For color matching, it can adapt the target palette to colors in the tile pool and uses colorspacious for perceptually accurate matching. The package can retrieve tile images from Flickr search results or albums through Flickr’s public API. Downloads include JSON attribution information. Flickr search queries can be filtered by license, but album downloads do not programmatically check licenses. The documentation says a pool of about 300 images is typically the minimum for good results. Installation is through pip or from source, and the installation page requires Python 3.5 or later. An optional parallel extra provides experimental parallelism features. The project invites experimentation with custom tile partitioning, color characterization, matching, and drawing strategies. Its tutorial demonstrates saving a mosaic as an image or displaying it with matplotlib. The newest release note listed in the documentation is version 0.3.1, dated 21 June 2019. The project license is BSD-3-Clause.

photomosaic offers flexible tile placement and color matching for Python-based image mosaics. Its documentation sets an approximate minimum tile-pool size, and Flickr album downloads do not programmatically verify licenses.

photomosaic suits Python users who want to assemble a target image from a custom collection of tile images and adjust tile layout or color matching. Users sourcing images from Flickr albums should account for the package’s lack of programmatic license checks for those downloads.

Photomosaic is a free, open-source Python package for turning a personal image collection into a larger photographic composition. It is best for developers, technical artists, and image teams that want to control tile geometry and matching in code rather than use a preset editor. Choose it for unusual layouts and customizable algorithms; look elsewhere if you need a current, turnkey desktop or web workflow.

Overview

Photomosaic builds a picture from many smaller images, with the result reading as one image from a distance. Its BSD-3-Clause license permits open-source use and modification, while the project explicitly welcomes contributions around matching, partitioning, and image harvesting. The documented release history ends with version 0.3.1 on 21 June 2019, so its extensibility is more compelling than its update cadence for users who expect an actively evolving product.

Installation is through pip or source and requires Python 3.5 or later. The tutorial shows saving a mosaic as an image file or displaying it with matplotlib. A cache of resized pool images can accelerate repeated renders, but drawing is typically the slowest stage, making large or iterative jobs better suited to users comfortable tuning a Python workflow.

Key features

Layouts shaped around the subject

Tiles need not form a uniform grid: Photomosaic mixes sizes and places images irregularly or with overlaps. It can subdivide regions containing more detail into smaller tiles, and a mask can make the partition roughly follow an edge. Those controls help create a recognizable subject or an intentionally organic composition, but they require more planning than a tool built around fixed templates.

Color-aware matching

The package adjusts the target palette toward colors present in the tile pool and uses colorspacious for perceptually accurate matching. This is useful when the source image contains hues your library lacks, because the overall match can stay coherent instead of forcing exact but unavailable colors. The quality of that result still depends on the breadth of the pool; the documentation puts a typical minimum at about 300 tile images.

Flickr acquisition and attribution

Included tools can download tiles from Flickr search results or albums through Flickr’s public API and save JSON attribution information alongside the images. Search queries support license filters, which helps when building a rights-conscious library. Album downloads do not programmatically check licenses, so importing an album requires your own permission review before publication.

Designed for customization

The project uses standard data structures and leaves room to experiment with tile partitioning, color characterization, matching, and drawing strategies. An optional parallel extra provides experimental parallelism features. These extension points reward Python users who need a bespoke pipeline; they are unnecessary overhead for someone seeking a guided mosaic maker.

Pricing

There is no paid tier, trial period, seat charge, or renewal. The trade-off for a zero-cost package is operational: you supply the Python environment, assemble the tile pool, and manage any Flickr licensing decisions yourself.

Platforms

Photomosaic targets Linux. Python 3.5 or later is required, with optional dependencies available through the parallel extra. PNG and JPG are supported output formats, and matplotlib can display a generated result.

Who it's for

Choose Photomosaic if you are comfortable installing Python packages and want control over irregular placement, adaptive detail, masks, color matching, and custom algorithms. It also suits teams building a repeatable image-generation pipeline where cached tile images and reusable libraries matter.

It is a poor fit for casual creators who want drag-and-drop composition, a hosted editor, or a recently maintained application with a polished interface. The approximately 300-image starting pool, slow drawing stage, and manual license checking for Flickr albums add work before a finished mosaic is ready.

Pros and cons

Pros

• Non-grid composition: mixed-size, irregular, and overlapping tiles support layouts a rigid square grid cannot.
• Subject-aware detail: adaptive subdivision and edge-tracing masks can give important contours finer treatment.
• Perceptual color matching: colorspacious and palette adaptation help reconcile a target image with the colors your library actually contains.
• Open customization: standard data structures and replaceable strategies make it practical to develop specialized partitioning or matching logic.
• No software fee: the BSD-3-Clause package costs nothing and includes PNG/JPG output plus tile reuse controls.

Cons

• Linux and Python requirement: setup is aimed at technical users rather than people seeking a cross-platform editor.
• Large source-library burden: good results typically need about 300 tile images, and sourcing them is your responsibility.
• Flickr album rights gap: album downloads do not automatically verify licenses, even though search queries can be filtered.
• Rendering bottleneck: drawing is usually the slowest step; caching helps repeated draws but does not remove the tuning work.
• Old documented release: version 0.3.1 from June 2019 may concern teams prioritizing recent maintenance.

Alternatives

• Picture Mosaics Online Mosaic Tool is better for browser, iOS, or API access and free creation with paid downloads, prints, and video files.
• Photo Mosaica suits iOS and macOS users who want adjustable diversity and size in a consumer application.
• EasyMoza is the choice for a web workflow with free low-resolution downloads and a one-time XL high-resolution option priced at $595.
• AndreaMosaic fits users needing Linux, macOS, or Windows support, with a free standard edition capped at 200 megapixels, 30,000 tiles, and 50,000 images.
• PhotoMosaic.ai is preferable for web-based, always-free creation with AI color matching and 4,800×4,800-pixel free output.
• PicTiler offers a web service with standard-quality output free for personal and commercial use.
• Rapid-Mosaic is a Windows option with local creation and a £29 one-time Professional upgrade.
• Mosaicify Studio provides unlimited, no-sign-up, no-watermark high-resolution downloads on the web.
• Photo Mosaic Software is a broader list for comparing additional mosaic tools.

Verdict

Photomosaic is the right choice for a Linux-based Python user who values control over tile geometry, adaptive detail, and color matching more than interface polish or recent release activity. Its main reason to choose it is unusually deep, scriptable composition at no software cost; its main reason to look elsewhere is the setup and maintenance work, including a sizable tile library and manual licensing checks for Flickr albums.