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A standard test image is a digital image file used across different institutions to test image processing and image compression algorithms. By using the same standard test images, different labs are able to compare results, both visually and quantitatively. The images are in many cases chosen to represent natural or typical images that a class of processing techniques would need to deal with. Other test images are chosen because they present a range of challenges to image reconstruction algorithms, such as the reproduction of fine detail and textures, sharp transitions and edges, and uniform regions.

The most widely published standard test image is the Lenna image, from a 1972 centerfold photograph of Playboy model Lena Soderberg.

1 Some common test images
- 1.1 Lenna (aka Lena, Girl)
- 1.2 Others
2 See also
3 External links

[edit] Some common test images

The standard size of the images are usually 512x512 or 720x576. Most of these images are freely available as TIFF files from the University of Southern California's Signal and Image Processing Institute [1].

Different images have different characteristics which are of particular use to the image scientist. Depending upon the application, it may be important that certain features are more accurately reproduced while others are less important. For example, satellite imaging of the earth for surveying purposes will require accurate edge reproduction, while satellite imaging for agricultural purposes will not. High correlated spatial frequencies, such as a series of closely spaced parallel lines, are often used as a test pattern, as well as low spatial frequencies, or flat areas. Uncorrelated high spatial frequencies (or "textures") are also often used. The use of a human face is very useful for informal judgements on image reproduction quality because the human eye and brain are particularly adapted to detect small variations in human facial features. This holds true to a lesser extent for animal faces. Even variations in everyday scenery can be detected more readily than a simple test pattern.

[edit] Lenna (aka Lena, Girl)

Lenna.png (512x512)

Main article: Lenna

Lenna is the most famous test image. It was scanned around 1973 at University of Southern California's signald and image processing institute. Perhaps it's popularity is because the image is of a Playboy centerfold, but the image has high spatial frequency (feather), low spatial frequency (shoulder, walls), edges (wall, hat, face), texture (hat), human face.

References

http://www.cs.mu.oz.au/~jjchua/publications/chua_tischer_ng_PCS96_quick.pdf

[edit] Others

Baboon.png (a.k.a Mandrill)	Name:Mandrill (a.k.a. Baboon) Size: 512x512 Characteristics: Texture (fur), High spatial frequency (whiskers), animal face References: http://www.cs.mu.oz.au/~jjchua/publications/chua_tischer_ng_PCS96_quick.pdf Note: This image is a strong test of a compression algorithm, due to the wide color variation and different textures.
Tiffany.png	Name: Tiffany Size: 512x512 Characteristics: High spatial frequency (hair), low spatial frequency (face), human face. References: Note:
Peppers.png	Name: Peppers Size: 512x512 Characteristics: low spatial frequency, edges, color variation. References: Note:
Peppers2.png	Name: Peppers2 Size: 512x512 Characteristics: low spatial frequency, edges, color variation. References: Note:
House.png	Name: House Size: 256x256 Characteristics: edges, low spatial frequency (sky), high spatial frequency (brick) References: Note:
Sailboat.png	Name: Sailboat Size: 512x512 Characteristics: edges, high spatial frequency References: Note:
Masuda1.png	Name: Masuda1 Size: 512x512 Characteristics: low spatial frequency (face, wall, hair) , human face References: See http://itohws03.ee.noda.sut.ac.jp/~matsuda/mrp/ for a bibliography Note:
Masuda2.png	Name: Masuda2 Size: 512x480 Characteristics: low spatial frequency (face, wall, hair) , human face References: See http://itohws03.ee.noda.sut.ac.jp/~matsuda/mrp/ for a bibliography Note:
Barbara.png	Name: Barbara Size: 787x576 Characteristics: High spatial frequency (chair back, books, tablecloth), low spatial frequency (floor,wall), color (toys), edges (book case, table legs), human face. References: Note: This was a posed picture specifically intended as a test image.
Zelda.png	Name: Zelda Size: 787x576 Characteristics: high spatial frequency (hair), low spatial frequency (face, background), human face References: Note:
Mouse.png	Name: Mouse Size: 320x200 Characteristics: high spatial frequency (whiskers), texture (fur), animal face References: Note:
Goldhill.png	Name: Goldhill Size: 787x576 Characteristics: References: Note:
Boats.png	Name: Fishing boats Size: 787x576 Characteristics: High spatial frequency (masts), low spatial frequency (sky, clouds), texture (water), edges (boat edges) References: Note:
Airplane.png	Name: Airplane (a.k.a. F16) Size: 512x512 Characteristics: High spatial frequency (mountain snow) low spatial frequency (sky), edges (plane) References: Note: