File:Kcc rescale 04 im triangle.jpg
Kcc_rescale_04_im_triangle.jpg (557 × 425 pixels, file size: 70 KB, MIME type: image/jpeg)
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Summary
DescriptionKcc rescale 04 im triangle.jpg |
English: Part of a series of images to compare and contrast the levels of spatial aliasing that can result when an image that contains some strong spatial frequencies is digitally rescaled. An image of an 1801 engraving of King's College Chapel, Cambridge was used as a test object, and resized to 50% using different filters and different programs.
The image on this page was resized to 50% using Image Magick 6.7.5 with the "triangle" option -- i.e. taking into account nearby pixels using a ramp filter. Compared to the box filter, this time the Moiré banding seems to be completely suppressed; but at the same time the buttresses of the chapel are also noticeably less sharp, making the building softer than it was with the box filter. Other images in the series look at the results of using various available lowpass filters to try to minimse or suppress such artefacts. |
Date | |
Source |
This file was derived from: F. Roffe after P. Nash (1801) - King's College Chapel - sanders13001.jpg an engraving first published in 1801. |
Author | John Roffe (1769-1850), engraver, after Frederick Nash (1782–1856) |
Other versions |
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Source code
convert kcc.jpg -filter triangle -resize 50% kcc_im_triangle.jpg
Licensing
This is a faithful photographic reproduction of a two-dimensional, public domain work of art. The work of art itself is in the public domain for the following reason:
The official position taken by the Wikimedia Foundation is that "faithful reproductions of two-dimensional public domain works of art are public domain".
This photographic reproduction is therefore also considered to be in the public domain in the United States. In other jurisdictions, re-use of this content may be restricted; see Reuse of PD-Art photographs for details. |
Items portrayed in this file
depicts
1801
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
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current | 19:08, 6 March 2012 | 557 × 425 (70 KB) | Jheald |
File usage
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Metadata
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If the file has been modified from its original state, some details may not fully reflect the modified file.
Orientation | Normal |
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Horizontal resolution | 400 dpi |
Vertical resolution | 400 dpi |
Software used | GIMP 2.6.12 |
File change date and time | 18:25, 5 March 2012 |
Color space | Uncalibrated |
Image width | 1,114 px |
Image height | 850 px |
Date and time of digitizing | 11:39, 4 June 2008 |
Date metadata was last modified | 11:39, 4 June 2008 |