BOLD – Birmingham Object Lighting Database

Please read these search tips before searching the database

BOLD Home

 

1. Overview

2. Viewing all images

3. Subject Driven Search

4. Lighting Driven Search and available lighting combinations.

5. Orientation parameter

6. Camera parameter

7. Filename search

8. Search results

9. Downloading images

10. Family zip files

11. Filename conventions

 


 

 

1. Overview

The BOLD database contains a large number of images such it is impractical to download the entire dataset. We have configured a search facility to help users find and download the images that suit their needs.

 

The database can be searched in 3 modes: Subject drive, Lighting driven and Filename driven.

 

Subject driven search is best for users who wish to find out what kinds of objects, people and scenes are available and to choose from those options. This search mode requires that the subject type (External, Object, Surface or Face), description (eg, cube, ripples, male, path), and treatment (eg paint treatments for surfaces and some objects, exposure for outdoor scenes) be selected from drop down lists. The user can then additionally restrict the search to certain lighting or pose conditions.

 

Lighting driven search is best for people who wish to see all the images that are lit with a given type of lighting it is also (paradoxically) the best way to view examples of all the images of a certain type. See Viewing all images/a>.

Filename searches provide the best way to obtain details relating to a file that you already know the name for.

 

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2. Viewing all images

It is not possible to view all the images at once. However it is possible to use Lighting based searches to find examples of large classes of subject type from which you can choose subjects and refine your lighting requirements.

 

To view an example of all external scenes

Step 1. Select Lighting based search.

Step 2. Select Diffuse = Sky

Step 3. Select Camera = Left

Step 3. Click search.

 

Because all external scenes were shot with the sky as a diffuse source this will display all the external scenes; and only external scenes. All 5 exposure settings will be shown but selecting the left camera will limit the output.

 

To view an example of each face/p>

Step 1. Select Lighting based search.

Step 2. Select Diffuse = Both

Step 7. Select Orientation = Frontal

Step 8. Select Camera = Left

 

This will show up a single example of each face.

 

To view all objects and surfaces.

Step 1. Select Lighting based search.

Step 2. Select Diffuse = Full

Step 3. Select Spot = Yes

Step 4. Set Elevation = 0

Step 5. Select Side = West

Step 6. Set Azimuth = 45

Step 7. Select Camera = Left

 

This will present one example of each surface / object and each treatment.

 

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3. Subject driven search.

This search mode is good for browsing the types of subject that are contained in the database. Choose the type of subject, the description and the treatment in that order from the drop down lists. The listed descriptions and treatments vary depending on the subject type. Note that as these lists apply to classes of subject and that not all of the treatments listed will be available for all descriptions. This can lead to frustration when no images are found despite the apparent availability of a subject. The best way to find out what treatment are available for a given subject description is to use the lighting based searches above.

 

Surfaces: There are seven treatment types for most surfaces (excluding natural). The white tile surface is available as natural only. To find out what surface images available enter Grey for the treatment.

 

Objects: Most objects are available as natural and grey (some natural only). Cubes are not available in the natural treatment. To find out what objects are available enter natural as the treatment but note that this will exclude cubes: Treatment grey will pick up cubes.

 

Faces:  Faces are available as male or female and all are designated as having the natural treatment.

 

External :  Treatments describe the degree of exposure applied to otherwise identical images. Treatments available are ‘Normal exposure’, ‘Over exposed’ and ‘Under exposed’. These are available for all external scenes. Because of the linear format of the images searching for over exposed images produces thumbnails that are more visible but these ultimately are not the most faithful representation of the original scene.

 

Recommended lighting settings.

For surface, object and face stimuli searching on type, description and treatment only can still produce a very large number of images. To best assess the range of image available given a particular type, description and treatment we recommend the following additional settings.

 

Surfaces and objects:

                Diffuse = Full

                Spot = Yes

                Elevation = 0

                Side = West

                Angle = 45

 

Faces:

                Diffuse = Both

                Spot = No

                Orientation = Frontal

 

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4. Lighting driven searches

Lighting driven searches allow the user to find example images taken under the same lighting conditions. In practice as the basic lighting parameters vary between objects/surfaces, faces and external scenes specific lighting searches only tend yield one type of image. The following lighting positions are available.

 

Objects and Surfaces:

Diffuse = full or none, fully diffuse lighting can appear alone or with a spot light.

Spot = yes or no, Spot lights can appear alone.

 

Elevation and Azimuth combinations. Note 0 degrees azimuth is listed in the database as west. West are east correspond to light from the left and right of the line of sight respectively but are used in stead of ‘left’ and ‘right’ which are used to denote the camera positions.

 

Elevations 0:/p>

Azimuths 90W – 0W –  75E in 15 degree steps.

 

Elevations 30 and 45/p>

Azimuths 90W – 0W – 90E in 15 degree steps.

 

Elevations 15, 60 and 75/p>

Azimuths 45W, 0W and 45E

 

Elevations 5, 10, 20, and 25

Azimuths 45E and 45W

 

Elevation 90

Azimuth 0W

 

Faces:

Diffuse = left, right, both or none. Diffuse lighting was provided by two ‘softbox’ lamps which were used in various combinations with spot lights for two different facial poses.

Spot = yes or no, spotlights can be used alone.

 

Lighting used for frontal poses

Left, right and both diffuse, left diffuse with spot and spot only at the following azimuths and elevations.

 

Azimuth 29E or 39E

Elevations 0, 4.5, 9, 13.5, 18, 22.5 and 27 degrees

 

Lighting used for portrait poses

Left and both diffuse, left diffuse with spot and spot only at the following azimuths and elevations.

 

Azimuth 29E

Elevations 0, 4.5, 9, 13.5, 18, 22.5 and 27 degrees

 

External:

External images were taken on sunny days with the sun as a spotlight and the sky as a diffuse light. Sun positions were calculated based on the position of the sun at the time of the photograph (estimated from latitude and longitude estimates the date and time of day), the compass heading of the camera line of sight and the slant (declination) of the camera. The relative sun positions are very approximate, vary from image to image and are listed in this file.

 

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5. Orientation parameter

The orientation search parameter applies only to face images and can be frontal or profile.

 

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6. Camera parameter

Two cameras were used with optical centres mounted 47.5mm either side of the line defined as the 0 elevation ,0 azimuth position for all lighting references. The cameras are called ‘left’ and ‘right’ respectively. Setting the camera parameter during a search will half the number of images returned without limiting the number of different subjects presented.

 

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7. Filename search

Only use this search mode if you have one of our files already downloaded and know its filename but want to access the stored data associated with it.

 

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8. Search results

Such results are displayed as image thumbnails and a list of the data stored in the database along side each image. Each image also has two icons one for downloading the individual image, the other for downloading the associated family zip file. Hovering over an image will show a slightly enlarged thumbnail. Do not download the image by right clicking on its thumbnails this will only download the thumbnail.

 

Example search results.

 example search results

 

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9. Downloading images.

To download and individual image click on the single image icon Single image download iconbelow and to the right of the image. This will open a full size image in a new window. Once the image is open right clicking will enable you to save it.

 

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10. Family zip files

Family zip files let you download multiple images at once. Family zip files contain all the images for a given subject taken with one camera (eg left or right). Zip files can be downloaded by clicking on the multiple image icon Family file download iconbelow and to the right of each thumbnail.

 

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11. Filename conventions.

Filenames for the surfaces, objects and faces have the following naming convention:

 

INNNN_TTT_dD_sSee.e_Eaa.a_O_C.png.

I denotes  the type of image; s=surface, o=object, f=face, x=external.

NNNN is the name or index number of the subject (an abbreviated name for surface and object images and index number for face and external images).

TTT is the treatment applied to the object or surface or NAT for natural.

D indicates the nature of the diffuse source; f=full, l=left, r=right, b=both, x=none.

S indicates the nature of the spot light (x=none, n=on and to the north)

ee.e is the elevation of the spot light.

E indicates if the spot light is to the east (e) or west (w) of the camera line of sight,

aa.a is the azimuth of the light source.

O indicates the orientation of the subject (f=frontal, p=profile, x for objects and surfaces).

C indicates which camera the image was taken with.

 

External images have a different naming convention given by:

INNNN_NAT_exposure_C.png

I, NNNN, and C are as above.

NAT is common to all external image filenames.

exposed is a code indicating the exposure of the image with ‘exposed’ indicating a normal exposure, ‘over__1’ and ‘over__2’ indicating 1 and 2 stops of over exposure and ‘under_1’ and ‘under_2’ one or two stop of under exposure respectively.

 

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