TIFF data volumes are influenced by the level of data compression. Approximate storage volumes: 16–80 Mb using LZW compression.

Image compression

When an image is compressed, duplicated data that has no value is removed or saved in a shorter form, reducing the file’s size. For example, if large areas of water are the same tone, only the value for one pixel needs to be saved, together with the locations of the other pixels with the same colour. When the image is edited or displayed, the compression process is reversed. When a raster is compressed, not only are the data volumes reduced, but the user can download, display, edit and transfer images more quickly.

There are two forms of compression: lossless and lossy.

Lossless compression

As its name suggests, lossless compression does not lose information within an image. A lossless compression retains the original quality of an image when it is uncompressed. This process does not provide much compression, so file sizes remain large. Lossless compression is used mainly where detail is important, such as when users are planning to make large prints.

Lossy compression

This process degrades images to some degree, meaning that the decompressed image is not quite the same as the original. The more an image is compressed, the more degraded it becomes. In many situations, such as posting images on the Internet or printing small- to medium-sized prints, the image degradation is not so obvious. If a lossy compressed image is over enlarged, the degradation will become apparent.

TIFF

TIFF is one of the most commonly used lossless image formats. TIFF is primarily designed for raster data interchange and is supported by numerous image-processing applications. This permits much more efficient access to very large files that have been compressed.

Shaded relief file

Raster examples of MiniScale with shaded relief are provided to show what can be achieved with the Illustrator files. The relief file is embedded with individual 100 km shaded relief images fitted to the National Grid. These can be added to the main MiniScale map by using Illustrator’s ‘Paste in front’ option. Use the ‘multiply’ setting to control the transparency and strength of the shaded relief.

Using add-on files/merging earlier files

The shaded relief tiles are provided in a second Illustrator file. The document size and position of this relief file match that of the main MiniScale Illustrator file. Use the ‘paste in front’ command to copy the relief into the right position on the MiniScale map. Position the relief layer for desired effect. Use the ‘multiply’ setting to make detail underneath show through. If the document size and position have been changed, then use the 100 km squares to fit the relief tiles to.

Managing MiniScale files

MiniScale has been created as a vector data graphic map that is favourable for use within desktop graphic

applications. MiniScale’s use within GIS will be limited to backdrop mapping when using the TIFF only.

MiniScale is supplied as a single download with a variety of industry-standard formats. The Illustrator vector data is held in layers, with styled objects for easy customisation of map images. These can be easily converted to web images using appropriate software (not supplied).

File formats

MiniScale is maintained using Adobe Illustrator software. All the capabilities of editing and styling MiniScale may not be available in other applications.

Raster versions are also provided at 254 dpi. The TIFFs are LZW compressed and in RGB colours. New raster files can be created, styled and layered as required by using the Illustrator data.

A 100 km grid is provided as a separate layer. This is set as an invisible layer by default. The 100 km grid is constructed from individual squares to enable them to be used easily for clipping and so on. A further non‑printing layer holds the 100 km letter references to ease identification of the squares. For Illustrator users, the rulers have been set to match the zero point for National Grid. When the file is used at 1:1 000 000 scale and providing the rulers or page position have not been moved, the measurements can be used as National Grid coordinates (preferences must be set to millimetres). For example, the tip of Flamborough Head has an Illustrator coordinate of x = 525.85 mm and y = 470.51 mm, which corresponds to a National Grid reference of 5258 4705 (or TA 258 705); in Illustrator, the y value will be a minus value.

National Grid coordinates for the raster versions

The raster files have been provided for GIS users who might otherwise be unable to use the Illustrator or EPS files. The origin (lower-left corner) of the GB file is 0, 0 km and it finishes at 700 km east and 1 300 km north of the National Grid origin. This equates, at 254 dpi, to 7 000 pixels wide by 13 000 pixels high

(100 km = 1 000 pixels).

Ireland and the Channel Islands

Parts of the French and Irish coastlines have been included to help give context to the position of Great Britain. Although reasonably accurate, they use different map projections to GB and fall outside the National Grid. Their position and scale are therefore approximate. This also applies to the Channel Islands.

Boundaries

National, county and unitary authority boundaries are shown. County and unitary boundaries are depicted by the same style. Boundaries within the London Authority area are shown on a separate optional extras layer.

To be able to view each tile in correct geographic relation to the National Grid and to each other, the tiles must be georeferenced. GIS typically provide georeferencing as part of their functionality, but for each set of tiles it is necessary to provide the information on how the tiles should be ordered. MiniScale TIFF tiles are in COG (Cloud Optimised GeoTIFF) format, which enables georeferencing information to be embedded within a TIFF file itself.

The Adobe Illustrator file is georeferenced using Avenza MapPublisher. This plugin provides GIS tools for Illustrator and unlocks additional attributes embedded in the MiniScale vector file. It is not a requirement for using the vector file for graphic output, but it does open up new ways of using MiniScale for those that do have the plugin.

The data is supplied as a download and is updated and released annually in January. It is supplied as the whole of Great Britain, with Orkney and the Shetland Islands shown in their correct positions. Some European coastline is supplied to give context.

MiniScale is supplied in the following formats (file sizes are approximate):

• Adobe Illustrator CC 2019 or higher; file size 30 Mb

• Editable Encapsulated PostScript (EPS); file size 95 Mb

• TIFF LZW compression; file size 15–40 Mb

The Illustrator file contains the layers and styles required to customise the product. This file also contains additional layers, such as sea depths, height colouring and other information that does not appear on the default style for MiniScale. Some of the ways that MiniScale can be customised are shown in the raster examples provided.

The Illustrator file requires the font ‘Source Sans Pro’, which is supplied in the download. This is a free open source font created by Adobe. It is available from Adobe and Font Squirrel: https://www.fontsquirrel.com/fonts/source-sans-pro.

Managing MiniScale files

MiniScale has been created as a vector data graphic map that is favourable for use within desktop graphic applications. MiniScale’s use within GIS will be limited to backdrop mapping when using the TIFF only.

MiniScale is supplied as a single download with a variety of industry-standard formats. The Illustrator vector data is held in layers, with styled objects for easy customisation of map images. These can be easily converted to web images using appropriate software (not supplied).

Graphic styles and Illustrator symbols are used in MiniScale to achieve the final look of the map and to aid in restyling the vector data. Some finishes are achieved using layer effects provided by Illustrator. For example, the boundaries layer setting applies an overall ‘multiply’ effect; if each of the boundary line paths were individually set to multiply, the result would not work. Illustrator users should be aware that the layer effect is lost if the contents of such layers are copied to a new document. In the table below, the * symbol indicates layers that have a layer effect applied.

Features

Names

Admin Boundaries

Communications

Water

Area Fills

Base Fills

Extras

Ordnance Survey’s MiniScale is a small-scale product designed for use within desktop graphic applications. It provides geographic context for the whole of Great Britain by showing major boundaries, lines of communication, settlements and physical features.

MiniScale is a vector graphic that has been created using desktop publishing software so that it can be customised and converted into a wide variety of graphic formats. Alternatively, the raster examples can also be used for web applications or within a geographical information system (GIS) as a backdrop.

MiniScale is aimed at any customer who requires a high-quality, visually appealing map for their documents and/or publications, whether that be a magazine, brochure or website.

An extract of MiniScale, with default layers and styles, is shown below.

Applications

Typical ways in which MiniScale could be used include:

• Creating location maps for websites or promotional material, for example, showing the locations of head offices or the distribution of assets across Great Britain.

• Facilitating high-level route planning along major roads and railways.

• Producing overview or entry screen maps within an Intranet or Internet web mapping service.

The smaller scale of MiniScale also lends itself to applications that need to show information at a regional or county/unitary level, where a larger-scale map would be too detailed or cluttered.

Overview

Scale

1:1 000 000 (1 mm = 1 km); MiniScale is designed to be used at viewing scales of between 1:700 000 and 1:2 000 000.

Coverage

Great Britain.

Source of MiniScale

MiniScale is a generalised hand drawn map, with updates derived from the 1:250 000 scale topographical digital database.

Legend

The following legend is for the default standard look supplied in the Illustrator vector file.

Currency

MiniScale is a hand drawn map. This enables us to achieve the extreme simplification, generalisation and ‘look’ of MiniScale. The data is updated using the latest available version of Ordnance Survey’s 1:250 000 scale topographical digital database as a guide.

Revision

The MiniScale master dataset is updated and released annually in January.

MiniScale is a free small-scale digital map of Great Britain in a single data file that clearly shows towns and cities, motorways, major roads, railways and airports. MiniScale is aimed at any customer who requires a high-quality, visually appealing map for their documents and/or publications, whether that be a magazine, brochure or website.

MiniScale is a vector graphic that has been created using desktop publishing software so that it can be customised and converted into a wide variety of graphic formats. Alternatively, the raster examples can also be used for web applications or within a geographical information system (GIS) as a backdrop.

How to get this product

Access to this product is free through the OS Data Hub.

Ordnance Survey’s MiniScale is a small-scale product designed for use within desktop graphic applications. It provides geographic context for the whole of Great Britain by showing the major boundaries, lines of communication, settlements and physical features.

MiniScale is a vector graphic that has been created using desktop publishing software so that it can be customised and converted into a wide variety of graphic formats. Alternatively, the raster examples can also be used for web applications or within a geographical information system (GIS) as a backdrop.

MiniScale is aimed at any customer who requires a high-quality, visually appealing map for their documents and/or publications, whether that be a magazine, brochure or website.

An extract of MiniScale, with default layers and styles, is shown below.

Specification

The following sections and subsections include information about MiniScale file compression, symbology, georeferencing and formats.

Data source

MiniScale is a redrawn and simplified product designed to meet the needs of the desktop graphics industry. Historically, it is based on a variety of Ordnance Survey digital datasets; however, the graphic output is now updated with changes identified in the 1:250 000 vector data base.

Availability

Great Britain

Scales

1:1 000 000 (1 mm = 1 km)

MiniScale is designed to be used at viewing scales of between 1:700 000 and 1:2 000 000.

Physical size (at scale above)

Great Britain = 700 mm wide by 1 300 mm high (with the Shetland Islands in position). Orkney and Shetland can be inset to reduce the height to about 1 000 mm.

Resolution

Postscript = resolution of output device Raster = 254 dpi

Supply media

Download

Data type

Desktop vector graphic (Illustrator and EPS vectors), CMYK colour space

Colour

Raster LZW data is RGB colour

Update interval

Great Britain data revised annually

Coordinate reference system

British National Grid (OSGB36)

Data structure and size

Postscript Vector

• Transfer formats: Editable EPS, Illustrator CC 2019

• Storage volumes (approximate): Editable 95 Mb, illustrator 30 Mb

• Layers and styles: see features layers and styles

Raster

• Transfer formats: TIFF LZW compressed 254 dpi

• Storage volumes (approximate): TIFF 15 – 40 Mb (choice of four example styles)

• Layers and styles: TIFF LZW – none

Fonts

The Illustrator file requires the font ‘Source Sans Pro’. This is a free open source font created by Adobe. It is available from Adobe and Font Squirrel:

http://www.fontsquirrel.com/fonts/source-sans-pro.

Colours

The default colours for MiniScale vectors are four-colour process (CMYK). MiniScale raster examples are supplied as TIFF LZW (RGB).

Software Requirements

MiniScale requires Illustrator CC 2019 or higher running on a PC or Apple Macintosh platform. Other EPS‑compatible software can also be used by importing the EPS files. Ordnance Survey does not specify hardware requirements as these are dependent on the software and applications within which the data will be used. Customers should contact their system or software supplier for advice.

Index

• National Grid

• Miniscale file management

MiniScale shows three classes of roads: A-Road with primary/non-primary styles and Motorway.

The primary (green) roads are the recommended through routes that complement the motorway system. Where there are significant lengths of dual carriageway, they have been shown with a dual carriageway style. The primary roads link primary route destination towns, which appear on green road signs. In congested urban areas, some roads have been omitted for clarity.

MiniScale settlements are shown in three levels: Primary route destination towns (large dot), other towns useful to the map (medium dot) and minor settlements (small dot).

Urban names have been given a range of point sizes and weights to visually differentiate them. No statistical relevance, such as size or population, should be inferred from this. Primary route destination names are all the same regardless of their physical size: thus, the hamlet of Scotch Corner appears the same on the map as a major town like Andover as these two settlements are both primary route destinations. Due to space issues, many suburban localities will be missing around major cities. The choice of which minor names we have space to show are weighted in favour of those that give context to the road network.

Welsh spellings

At the scale used for MiniScale it is impractical to show all the Welsh names with dual spellings (English and Welsh). However, the Illustrator file contains an extra layer of Welsh names that can be used to replace the English ones; this requires manual intervention since the Welsh names are in the same position as the English names.

Shaded relief file

Raster examples of MiniScale with shaded relief are provided to show what can be achieved with the Illustrator files. The relief file is embedded with individual 100 km shaded relief images fitted to the National Grid. These can be added to the main MiniScale map by using Illustrator’s ‘Paste in front’ option. Use the ‘multiply’ setting to control the transparency and strength of the shaded relief.

Resolution

The resolution of the master vector Illustrator file is only limited by the output device.

The example raster files are at a resolution of 10 dots per mm (dpmm) or 254 dots per inch (dpi), and a pixel equates to 100 metres on the ground. This resolution maintains the necessary clarity of text for on screen use but is not considered suitable for high-quality printing.

MiniScale - Legend

Miniscale clearly shows towns and cities, motorways, major roads, railways and airports. A guide to the symbols depicted on this product is available as a PDF download from the .