4.1. Slice images into patches using a RegionSet

Sometimes it is necessary to save the actual image patches generated by a RegionSet, e.g. for a poster / talks slide or simply to verify that the correct image areas are selected. This short example script exports all patches generated by a 4x3 grid on all images from the tutorial image set (15 images) into PNG files (15 x 12 = 180 output files!).

In [2]:
#!/usr/bin/python3
# -*- coding: utf-8 -*-

from gridfix import *
"""
Creates a 4x3 grid region set, then cuts out all selected regions from every image in the
example ImageSet and save them to individual files.
"""

imgs = ImageSet('images/tutorial_images.csv', label='tutorial')
grid = GridRegionSet(imgs.size, (4, 3))

grid.export_patches_from_set(imgs, crop=True)

4.2. Effects of local saliency on fixation probability

This example illustrates one of the most basic use cases of the GridFix toolbox: how does the local saliency value calculated by a given model of visual saliency influence fixation probabilities?

In [2]:
#!/usr/bin/python3
# -*- coding: utf-8 -*-

from gridfix import *
"""
Evaluates maps generated by the saliency model of Itti, Koch & Niebur (1998)
for their predictive power of fixations on an 8x6 regular grid. This is a minimal
example for a GridFix analysis using a single feature.
"""

# Analysis grid
grid = GridRegionSet((800, 600), (8, 6))

# Saliency maps and corresponding feature
maps = ImageSet('maps/tutorial_maps.csv', mat_var='IKN98')
sal = MapFeature(grid, maps) # default = mean

# Fixation data with custom column names
fix = Fixations('tutorial_fixations.csv', imageid='image_id', fixid='CURRENT_FIX_INDEX',
                x='CURRENT_FIX_X', y='CURRENT_FIX_Y', imageset=maps)

# Generate model predictors
salmodel = FixationModel(fix, grid, chunks=['subject_number', 'image_id'], features=[sal])
salmodel.save('example2')

print(salmodel.predictors)
    subject_number image_id  region  dvFix    fMapFe
0            201.0      106     1.0    0.0  0.011996
1            201.0      106     2.0    0.0  0.051250
2            201.0      106     3.0    0.0  0.029515
3            201.0      106     4.0    0.0  0.032837
4            201.0      106     5.0    0.0  0.020327
5            201.0      106     6.0    0.0  0.038597
6            201.0      106     7.0    0.0  0.024676
7            201.0      106     8.0    0.0  0.017135
8            201.0      106     9.0    0.0  0.029146
9            201.0      106    10.0    1.0  0.129266
10           201.0      106    11.0    0.0  0.088838
11           201.0      106    12.0    0.0  0.169775
12           201.0      106    13.0    0.0  0.093220
13           201.0      106    14.0    0.0  0.085825
14           201.0      106    15.0    0.0  0.046923
15           201.0      106    16.0    0.0  0.025545
16           201.0      106    17.0    1.0  0.209219
17           201.0      106    18.0    0.0  0.231642
18           201.0      106    19.0    1.0  0.130784
19           201.0      106    20.0    1.0  0.310311
20           201.0      106    21.0    0.0  0.447962
21           201.0      106    22.0    1.0  0.709044
22           201.0      106    23.0    1.0  0.224838
23           201.0      106    24.0    0.0  0.029678
24           201.0      106    25.0    1.0  0.343682
25           201.0      106    26.0    0.0  0.203359
26           201.0      106    27.0    1.0  0.146591
27           201.0      106    28.0    1.0  0.328040
28           201.0      106    29.0    1.0  0.507897
29           201.0      106    30.0    0.0  0.431581
..             ...      ...     ...    ...       ...
18           209.0       97    19.0    1.0  0.595876
19           209.0       97    20.0    1.0  0.411496
20           209.0       97    21.0    1.0  0.464216
21           209.0       97    22.0    1.0  0.660822
22           209.0       97    23.0    1.0  0.664543
23           209.0       97    24.0    0.0  0.308240
24           209.0       97    25.0    0.0  0.154441
25           209.0       97    26.0    1.0  0.506913
26           209.0       97    27.0    0.0  0.566026
27           209.0       97    28.0    0.0  0.508420
28           209.0       97    29.0    0.0  0.229688
29           209.0       97    30.0    0.0  0.649280
30           209.0       97    31.0    0.0  0.492168
31           209.0       97    32.0    1.0  0.264287
32           209.0       97    33.0    0.0  0.144345
33           209.0       97    34.0    0.0  0.461687
34           209.0       97    35.0    0.0  0.293705
35           209.0       97    36.0    0.0  0.096766
36           209.0       97    37.0    0.0  0.064559
37           209.0       97    38.0    0.0  0.128566
38           209.0       97    39.0    0.0  0.231390
39           209.0       97    40.0    1.0  0.324227
40           209.0       97    41.0    0.0  0.041193
41           209.0       97    42.0    0.0  0.092233
42           209.0       97    43.0    0.0  0.073489
43           209.0       97    44.0    0.0  0.038960
44           209.0       97    45.0    0.0  0.041190
45           209.0       97    46.0    0.0  0.044402
46           209.0       97    47.0    0.0  0.066324
47           209.0       97    48.0    0.0  0.141121

[5760 rows x 5 columns]
In [ ]: