About the data set

CSF flattening due to the masking signal

This data set was measured to demonstrate the effect of CSF flattening in complex images. Gabor patches from 4 to 16 cpd were superimposed on an actual image (portrait) in three different regions: the region with almost no masking (hair), with moderate masking (face) and with strong masking (band). The hair region has almost no masking because the pixel values are clamped at 0. Note that also the luminance varies greatly between these three regions.

The thresholds were measured in the 4-alternative-forced-choice experiment, in which all four images were shown side-by-side. The measurement procedure was the same as for the "Contrast sensitivity for wide luminance range" data set.

Stimuli list

All stimuli shown at the detection threshold magnified x10. The visible banding (quantization) is due to 8-bit image files and display panel and is not present in the actual data.

cultural_mix band sin 4

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix band sin 6

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix band sin 8

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix band sin 16

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix face sin 4

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix face sin 6

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix face sin 8

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix face sin 16

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix hair sin 4

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix hair sin 6

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix hair sin 8

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60

cultural_mix hair sin 16

mean luminance = 14.5565 cd/m²
threshold_p = 0.66
surround_l = 10
viewing_distance = 0.9
rgb_display = led-lcd
pixels_per_degree = 60