Was El Greco Astigmatic?

Anstis, Stuart

doi:10.1162/00240940252940612

“…As with the reproduction of geometric form in painting, the above results may imply that we have fallen for a variation of the "El Greco fallacy" (see Anstis, 2002). This fallacy is the argument that El Greco painted elongated figures because he suffered from astigmatism and saw the world elongated.…”

Section: Discussionmentioning

confidence: 93%

Statistical regularities of art images and natural scenes: Spectra, sparseness and nonlinearities

Graham

¹

,

Field

²

2008

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Paintings are the product of a process that begins with ordinary vision in the natural world and ends with manipulation of pigments on canvas. Because artists must produce images that can be seen by a visual system that is thought to take advantage of statistical regularities in natural scenes, artists are likely to replicate many of these regularities in their painted art. We have tested this notion by computing basic statistical properties and modeled cell response properties for a large set of digitized paintings and natural scenes. We find that both representational and non-representational (abstract) paintings from our sample (124 images) show basic similarities to a sample of natural scenes in terms of their spatial frequency amplitude spectra, but the paintings and natural scenes show significantly different mean amplitude spectrum slopes. We also find that the intensity distributions of paintings show a lower skewness and sparseness than natural scenes. We account for this by considering the range of luminances found in the environment compared to the range available in the medium of paint. A painting's range is limited by the reflective properties of its materials. We argue that artists do not simply scale the intensity range down but use a compressive nonlinearity. In our studies, modeled retinal and cortical filter responses to the images were less sparse for the paintings than for the natural scenes. But when a compressive nonlinearity was applied to the images, both the paintings' sparseness and the modeled responses to the paintings showed the same or greater sparseness compared to the natural scenes. This suggest that artists achieve some degree of nonlinear compression in their paintings. Because paintings have captivated humans for millennia, finding basic statistical regularities in paintings' spatial structure could grant insights into the range of spatial patterns humans find compelling.

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“…Previous work by Taylor et al, (1999;2002) has demonstrated that Jackson Pollock's drip paintings resemble the basic statistics of natural scenes: the fractal dimension of Pollock's paintings was found to have increased over a small range in a relatively orderly way during Pollock's experimentation with drip-painting techniques. Pollock paintings' fractal dimension value range spans a similar range as do 1D natural scene outlines (Spehar et al, 2002).…”

Section: Discussionmentioning

confidence: 94%

Statistical regularities of art images and natural scenes: Spectra, sparseness and nonlinearities

Graham¹,

Field²

2008

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Paintings are the product of a process that begins with ordinary vision in the natural world and ends with manipulation of pigments on canvas. Because artists must produce images that can be seen by a visual system that is thought to take advantage of statistical regularities in natural scenes, artists are likely to replicate many of these regularities in their painted art. We have tested this notion by computing basic statistical properties and modeled cell response properties for a large set of digitized paintings and natural scenes. We find that both representational and non-representational (abstract) paintings from our sample (124 images) show basic similarities to a sample of natural scenes in terms of their spatial frequency amplitude spectra, but the paintings and natural scenes show significantly different mean amplitude spectrum slopes. We also find that the intensity distributions of paintings show a lower skewness and sparseness than natural scenes. We account for this by considering the range of luminances found in the environment compared to the range available in the medium of paint. A painting's range is limited by the reflective properties of its materials. We argue that artists do not simply scale the intensity range down but use a compressive nonlinearity. In our studies, modeled retinal and cortical filter responses to the images were less sparse for the paintings than for the natural scenes. But when a compressive nonlinearity was applied to the images, both the paintings' sparseness and the modeled responses to the paintings showed the same or greater sparseness compared to the natural scenes. This suggest that artists achieve some degree of nonlinear compression in their paintings. Because paintings have captivated humans for millennia, finding basic statistical regularities in paintings' spatial structure could grant insights into the range of spatial patterns humans find compelling.

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“…Perceived contrast moreover showed compensation for the orientation-selective sensitivity losses in astigmatic observers (Georgeson & Sullivan, 1975). Finally, adjustments to astigmatism have also been described for individuals who wore cylindrical lenses for prolonged periods (Anstis, 2002; Yehezkel, Belkin, Sagi, & Polat, 2005). …”

Section: Introductionmentioning

confidence: 99%

Adaptation to astigmatic blur

Sawides

¹

,

Marcos

²

,

Ravikumar

³

et al. 2010

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Adapting to blurred or sharpened images alters the perceived focus of subsequently viewed images. We examined whether these adaptation effects could arise from actual sphero-cylindrical refractive errors, by testing aftereffects in images simulating second-order astigmatism. Image blur was varied from negative (vertical) through isotropic to positive (horizontal) astigmatism while maintaining constant blur strength. A 2AFC staircase was used to estimate the stimulus that appeared isotropically blurred before or after adapting to images with astigmatism. Adaptation to horizontal blur caused isotropically blurred images to appear vertically biased and vice versa, shifting the perceived isotropic point toward the adapting level. Aftereffects were similar for different types of images and showed partial selectivity so that strongest effects generally occurred when testing and adapting images were the same. Further experiments explored whether the adaptation depended more strongly on the blurring or “fuzziness” in the images vs. the apparent “figural” changes introduced by the blur, by comparing how the aftereffects transfer across changes in size or orientation. Our results suggest that strong selective adaptation can occur for different lower order aberrations of the eye and that these may be at least partly driven by the apparent figural changes that blurring introduces into the retinal image.

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Was El Greco Astigmatic?

Cited by 25 publications

References 1 publication

Statistical regularities of art images and natural scenes: Spectra, sparseness and nonlinearities

Statistical regularities of art images and natural scenes: Spectra, sparseness and nonlinearities

Statistical regularities of art images and natural scenes: Spectra, sparseness and nonlinearities

Adaptation to astigmatic blur

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