Human sensitivity to phase perturbations in natural images: a statistical framework.

نویسندگان

  • M G Thomson
  • D H Foster
  • R J Summers
چکیده

Fourier-phase information is important in determining the appearance of natural scenes, but the structure of natural-image phase spectra is highly complex and difficult to relate directly to human perceptual processes. This problem is addressed by extending previous investigations of human visual sensitivity to the randomisation and quantisation of Fourier phase in natural images. The salience of the image changes induced by these physical processes is shown to depend critically on the nature of the original phase spectrum of each image, and the processes of randomisation and quantisation are shown to be perceptually equivalent provided that they shift image phase components by the same average amount. These results are explained by assuming that the visual system is sensitive to those phase-domain image changes which also alter certain global higher-order image statistics. This assumption may be used to place constraints on the likely nature of cortical processing: mechanisms which correlate the outputs of a bank of relative-phase-sensitive units are found to be consistent with the patterns of sensitivity reported here.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Monitoring of urban subway lines subsidence Using satellite radar interferometry method (Study area: Part of Tehran Metro Line 7)

Nowadays, satellite radar interferometry method plays an important role in calculating natural and artificial displacements, including displacements caused by floods, earthquakes, landslides, drilling of unauthorized wells, drilling of urban tunnels, etc. Metro tunneling is very important due to the importance of preventing irreparable financial and human losses. In Tehran, especially due to th...

متن کامل

An Efficient Curvelet Framework for Denoising Images

Wiener filter suppresses noise efficiently. However, it makes the out image blurred. Curvelet preserves the edges of natural images perfectly, but, it produces visual distortion artifacts and fuzzy edges to the restored image, especially in homogeneous regions of images. In this paper, a new image denoising framework based on Curvelet transform and wiener filter is proposed, which can stop nois...

متن کامل

Statistics of gradient directions in natural images

Interest in finding statistical regularities in natural images has been growing since the advent of information theory and the advancem ent o f the efficient coding hypothesis that the human visual system is optimised to encode natural visual stimuli. In this thesis, a statistical analy­ sis o f gradient directions in an ensem ble o f natural images is reported. Inform ation-theoretic measures ...

متن کامل

Cortical Activity During Postural Recovery in Response to Predictable and Unpredictable Perturbations in Healthy Young and Older Adults: A Quantitative EEG Assessment

Introduction: To investigate the effects of predictable and unpredictable external perturbations on cortical activity in healthy young and older adults. Methods: Twenty healthy older and 19 healthy young adults were exposed to predictable and unpredictable external perturbations, and their cortical activity upon postural recovery was measured using a 32-channel quantitative encephalography. Th...

متن کامل

Receptive Field Encoding Model for Dynamic Natural Vision

Introduction: Encoding models are used to predict human brain activity in response to sensory stimuli. The purpose of these models is to explain how sensory information represent in the brain. Convolutional neural networks trained by images are capable of encoding magnetic resonance imaging data of humans viewing natural images. Considering the hemodynamic response function, these networks are ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Perception

دوره 29 9  شماره 

صفحات  -

تاریخ انتشار 2000