Crowd-counting models deployed on edge devices face two shifts: inputs are degraded along the capture and transmission pipeline, while models are quantized to satisfy resource constraints. Yet corruption robustness and deployment quantization are typically evaluated separately. We introduce CrowdCC, a controlled corruption benchmark that jointly evaluates these effects using 23 deployment-motivated corruptions at three severity levels, four crowd-counting datasets, and 26 models using A100 TensorRT engines at FP32, FP16, and post-training INT8 precision, paired with throughput and energy measurements from corresponding Jetson Orin NX configurations. The corruptions span six families, with head annotations adjusted when geometry or visibility changes. Our evaluation shows that capture-chain corruptions consistently produce the largest degradation across the evaluated models, while crowd density affects absolute and relative error differently. Clean accuracy does not fully predict corrupted performance. INT8 alters corruption robustness substantially more than FP16, with no systematic direction, and does not consistently improve latency or energy. INT8 inference efficiency is strongly associated with reformat overhead in the compiled engine, while slowdowns are also observed under limited INT8 coverage. Precision changes corrupted-error rankings and robustness-cost frontiers, showing why model selection must consider corruption robustness and measured deployment cost together. The code is available at https://github.com/Tulane-Computer-Architecture-Systems/CrowdCC-Release.
Figures & tables
Figure 1: Corruption sources along the capture pipeline. Four families act during image formation and delivery; scene clutter and visibility loss act beforehand.
(a) base datasets and the instances they generate
Dataset
Inst.
#test-image
Res. (MP)
count min / max
mean
ShanghaiTech A
SHA-C
182
0.06 – 1.02
66 / 2,256
433.3
ShanghaiTech B
SHB-C
316
0.79
9 / 539
123.8
UCF-QNRF
QNRF-C
334
0.08 – 36.15
65 / 4,535
718.9
JHU-Crowd++
JHU-C
1,600
0.05 – 36.15
0 / 9,059
326.2
Table 1: CrowdCC at a glance. (a) Full labelled test splits, 2,432 images. (b) 23 corruptions in six families; alt. counts the 7 geometry-altering members.
Figure 2: Corruption severity across six families. One UCF-QNRF image is shown for one corruption from each family in Tab. 1 , across all three calibrated severity levels.
realized engine
Model
∣θ∣ (M)
Output type
FP16 or FP32 ops.
INT8 ×
E8/E16
CNN–based
CHF [ 39 ]
21.51
D
–
1.99
0.50
DM-Count [ 45 ]
21.50
D
–
1.98
0.48
GCHF [ 39 ]
21.51
D
–
1.98
0.49
CSRNet [ 24 ]
16.26
D
–
1.97
0.49
Table 2: Evaluated models and INT8 deployment efficiency. Output types D/B/P/C denote density maps, blockwise count maps, localization-oriented outputs, and direct count regressors. The FP16 or FP32 ops. column lists operations retained above INT8; superscript f denotes FP32. Speed and energy ratios are four-dataset medians relative to FP16. Bold indicates INT8 engines that are slower or consume more energy than FP16.
Model
SHA
SHB
QNRF
JHU
CHF
57.2/57.3/ 55.7
7.3/7.3/7.9
84.2/84.1/85.7
60.4/60.4/ 60.3
DM-Count
65.7/65.7/66.0
7.8/7.8/7.9
91.5/91.5/91.8
62.4/62.4/62.4
GCHF
59.2/59.2/ 58.1
7.1/7.1/8.3
81.8/81.8/84.1
60.4/60.3/60.5
CSRNet
67.4/67.4/68.2
11.4/11.4/ 11.1
95.8/95.9/96.7
68.9/68.9/ 68.8
P2PNet
57.8/57.8/ 57.5
8.0/8.0/8.1
101.0/101.1/102.0
66.9/66.9/ 65.8
APGCC
57.9/57.9/ 57.3
8.3/8.3/8.6
110.4/110.4/ 105.5
72.7/72.8/73.4
Table 3: Clean MAE by executed precision. Entries are FP32/FP16/INT8. Lower is better. A bold INT8 value is lower than at least one higher-precision value.
Figure 3: FP32 corruption sensitivity across counting metrics. Mean relative degradation across 26 models, four datasets, and three severities, ordered by MAE. † Geometry-altering corruptions use transformed annotations and kept-annotation error.
mcMAE (FP32/INT8)
FP32
INT8
FP32 RD % by corruption family
Model
SHA
SHB
QNRF
JHU
RD %
mCE
RD %
mCE
Env
Opt
Sen
Enc
Clu
Vis
CHF
74.8/73.6
17.4/16.8
107.0/107.0
72.2/72.8
28.9
0.821
28.5
0.824
62.6
77.5
78.6
38.2
11.5
35.3
DM-Count
81.0/81.1
16.3/15.9
110.0/109.5
73.5/73.0
21.7
0.840
21.1
0.838
38.2
60.4
68.7
32.7
12.8
22.4
GCHF
73.4/72.5
14.2/14.6
104.9/105.9
74.7/75.1
26.1
0.797
25.3
0.812
39.2
60.4
65.6
33.0
18.3
33.1
CSRNet
87.2/87.9
26.5/26.1
120.8/120.1
86.2/85.8
27.8
1.000
26.8
1.000
66.8
71.6
87.9
38.0
7.8
20.5
P2PNet
80.7/82.1
18.7/18.4
117.7/118.4
77.5/77.2
28.1
0.887
30.1
0.892
49.9
62.7
96.8
35.1
15.3
21.8
Table 4: Corrupted error, degradation, and the corruption family that breaks each model. Left: mcMAE per dataset as FP32/INT8, then median RD and mean mCE for each executed precision. Right: FP32 RD by corruption family — Env(ironment), Opt(ics and motion), Sen(sor and exposure), Enc(oding and transport), Clu(tter), Vis(ibility loss). Lower is better throughout. Bold marks the best model in each left-hand column and each model’s own worst family on the right.
Output representation
n
RD (%)
mCE
∣ΔRD∣
D Density map
15
23.6
0.857
2.55
B Blockwise count map
5
22.9
0.916
2.74
P Localization-oriented
4
25.9
0.913
1.97
C Direct count
2
14.0
0.859
0.75
Table 5: Robustness by output representation. Group medians over the models in each group. Lower is better; ∣ΔRD∣ compares INT8 with FP32 and the other columns are FP32.
Figure 4: Crowd-size dependence of corruption error. Images are stratified by dataset-specific clean-count quartiles; parentheses report the median of the four dataset medians.
Figure 5: Counting and localization degradation differ. Each point denotes one FP32 corruption across four native-point models. Dashed: least-squares fit; labels mark the largest deviations on either side.
Figure 6: Precision interaction and INT8 execution. In (a) , the band denotes the FP16 95th-percentile range ( ±0.39 percentage points). In (b) , values below one indicate slowdown; labels denote 1 MCNN, 2 FFNet-MobileNetV3, 3 FFNet-ConvNeXt-T, and 4 ZIP-Small.
Figure 7: Runtime decomposition. Four-dataset median end-to-end time per image for five models with INT8 slowdown (red) and four faster controls. Hatched bars denote INT8; non-GPU time includes preprocessing, transfer, dispatch, and engine residual.
Figure 8: Robustness–energy Pareto frontier. Median INT8 energy on Jetson vs. four-dataset mCE. Shading denotes an equal-cost band; green labels indicate Pareto-undominated models.
Figure 9: Accuracy, robustness, and deployment cost induce different rankings. Each point denotes a model–precision configuration, plotted by Orin energy per image and mean-corruption MAE. The dashed line marks the Pareto frontier; four representative members are labelled.
Appendix figures & tables27 assets
Supplementary material from the paper’s appendix.
Appendix
Corruption
Mechanism
Parameter
Light
Mod.
High
Sensor & exposure
fixed_pattern_sensor_noise
stuck/hot pixels, column FPN [ 13 ]
column σ
0.002
0.008
0.012
stuck_fraction
0.00005
0.0002
0.0003
row_sigma
0.002
0.008
0.012
temporal_sigma
0.002
0.008
0.012
gaussian_noise
sensor read noise [ 13 ]
σ
0.010
0.025
0.050
Appendix
Table A.1 : Corruption specification and severity calibration. Mechanisms and severity-dependent parameters for all 23 corruptions at Light, Moderate, and High severity. ↓ denotes parameters that decrease with severity; † denotes corruptions requiring transformed head annotations.
magnitude per dataset (px)
Corruption
Level
spacing frac.
SHA
SHB
QNRF
JHU
median head spacing (px)
17.23
33.11
34.78
32.99
camera motion blur
L
0.050
0.9
1.7
1.7
1.6
M
0.150
2.6
5.0
5.2
4.9
H
0.250
4.3
8.3
8.7
8.2
far-field defocus
L
0.050
0.9
1.7
1.7
1.6
Appendix
Table A.2 : Spacing-relative severity calibration. Severity is expressed as a fraction of median nearest-neighbour head spacing; dataset columns report the corresponding pixel magnitudes.
point
heads removed (%)
Corruption
rule
min
med
max
field-of-view loss
crop
12.3
25.1
80.3
foreground occlusion
occlusion
5.5
16.2
30.7
object distractors
occlusion
6.3
11.9
21.5
packet-loss concealment
occlusion
5.8
11.9
26.3
crowd-like distractors
occlusion
3.6
10.4
29.8
Appendix
Table A.3 : Annotation loss under target-altering corruptions. Fraction of head annotations removed by each transformation: minimum, median and maximum over all evaluated cells.
Figure B.1 : Corruption visualizations across severity levels. The same UCF-QNRF image is shown under all 23 corruptions at Light, Moderate, and High severity. Gaussian noise and fixed-pattern noise use native-resolution centre crops because downsampling suppresses their fine-scale effects.
Figure B.2 : Severity response by corruption family. Mean FP32 relative degradation across the three severity levels, grouped by family. All 23 corruptions increase monotonically in aggregate, with far-field defocus showing the steepest rise ( 17.71% – 181.89% ).
Figure B.3 : Synthetic weather calibration. All rain and snow severities fall within the JHU-Crowd++ real-weather inter-decile ranges for the selected appearance statistics.
Figure B.4 : Corruption-response redundancy. Spearman correlations between FP32 corruption-response profiles, ordered by average-linkage clustering on 1−ρ ; markers denote corruption families. The median correlation is 0.52 , with one pair above ρ=0.90 (lens flare and depth-aware haze, ρ=0.94 ) and seven additional pairs in [0.80,0.90) .
ShanghaiTech A
ShanghaiTech B
UCF-QNRF
JHU-Crowd++
Model
Ours
Paper
Ours
Paper
Ours
Paper
Ours
Paper
CNN-based
FFNet-MobileNetV3
70.68/118.90
64.30/109.30
12.64/23.91
–
107.94/198.67
–
65.14/233.29
–
ZIP-Pico
79.88/125.90
71.18/109.60
9.73/15.35
8.23/12.62
111.62/173.88
96.29/161.82
75.96/285.50
–
ZIP-Nano
70.49/109.17
58.86/94.63
8.50/13.69
7.74/12.14
114.44 / 196.29
86.46/147.64
73.53/275.65
–
MobileCount
86.66 / 139.69
89.40/146.00
9.24/ 14.94
9.00/15.40
114.69 / 189.84
131.10/222.60
137.04/397.79
–
Appendix
Table C.1 : Reproduction against published results. Clean FP32 MAE/RMSE on each full test split compared with published values for 26 models. Green indicates a value lower than published, and red marks a relative difference exceeding the 30 % reproduction threshold. Dashes denote unavailable references.
clean MAE
mcMAE
RD (%)
Model
FP32
FP16
INT8
FP32
INT8
FP32
FP16
INT8
ΔRD
APGCC
57.9
57.9
57.3
75.4
76.1
+30.4
+30.2
+32.7
+2.3
CHF
57.2
57.3
55.7
74.8
73.6
+30.7
+30.7
+32.2
+1.5
GCHF
59.2
59.2
58.1
73.4
72.5
+24.0
+24.0
+24.8
+0.7
CCST
63.6
63.6
63.2
72.3
72.0
+13.8
+13.7
+13.9
+0.2
CCTrans-Full
57.3
57.4
59.7
70.5
73.2
+23.0
+22.8
+22.6
-0.3
Appendix
Table D.1 : Robustness results, ShanghaiTech A. Clean MAE, mcMAE, and RD by precision. RD uses the corresponding clean baseline; ΔRD=RDINT8−RDFP32 in percentage points.
clean MAE
mcMAE
RD (%)
Model
FP32
FP16
INT8
FP32
INT8
FP32
FP16
INT8
ΔRD
APGCC
8.3
8.3
8.6
18.5
18.8
+122.5
+122.9
+118.9
-3.6
CHF
7.3
7.3
7.9
17.4
16.8
+139.4
+139.4
+112.8
-26.6
GCHF
7.1
7.1
8.3
14.2
14.6
+100.2
+100.3
+76.8
-23.4
CCST
8.1
8.1
8.3
13.8
13.7
+69.4
+69.7
+65.4
-4.0
CCTrans-Full
7.5
7.5
8.1
12.5
13.7
+66.0
+66.2
+68.8
+2.7
Appendix
Table D.2 : Robustness results, ShanghaiTech B. Clean MAE, mcMAE, and RD by precision. RD uses the corresponding clean baseline; ΔRD=RDINT8−RDFP32 in percentage points.
clean MAE
mcMAE
RD (%)
Model
FP32
FP16
INT8
FP32
INT8
FP32
FP16
INT8
ΔRD
APGCC
110.4
110.4
105.5
136.1
131.0
+23.3
+23.2
+24.1
+0.9
CHF
84.2
84.1
85.7
107.0
107.0
+27.1
+27.1
+24.8
-2.3
GCHF
81.8
81.8
84.1
104.9
105.9
+28.2
+28.1
+25.9
-2.3
CCST
96.3
96.2
96.7
106.5
107.5
+10.6
+10.7
+11.2
+0.6
CCTrans-Full
92.3
92.3
91.2
99.5
101.2
+7.8
+7.8
+10.9
+3.1
Appendix
Table D.3 : Robustness results, UCF-QNRF. Clean MAE, mcMAE, and RD by precision. RD uses the corresponding clean baseline; ΔRD=RDINT8−RDFP32 in percentage points.
clean MAE
mcMAE
RD (%)
Model
FP32
FP16
INT8
FP32
INT8
FP32
FP16
INT8
ΔRD
APGCC
72.7
72.8
73.4
80.9
81.2
+11.3
+11.2
+10.7
-0.5
CHF
60.4
60.4
60.3
72.2
72.8
+19.6
+19.7
+20.6
+1.0
GCHF
60.4
60.3
60.5
74.7
75.1
+23.7
+23.6
+24.1
+0.5
CCST
61.4
61.4
61.2
67.5
67.9
+9.9
+9.9
+11.0
+1.1
CCTrans-Full
56.8
56.8
59.1
63.8
67.8
+12.3
+12.3
+14.7
+2.4
Appendix
Table D.4 : Robustness results, JHU-Crowd++. Clean MAE, mcMAE, and RD by precision. RD uses the corresponding clean baseline; ΔRD=RDINT8−RDFP32 in percentage points.
SHA
SHB
QNRF
JHU
Corruption
F32
I8
F32
I8
F32
I8
F32
I8
far-field defocus
22
24
320
303
29
26
24
23
highlight clipping
40
42
227
223
49
48
30
30
depth-aware haze
39
37
252
244
28
27
18
16
Gaussian noise
49
51
183
182
35
38
58
59
lens flare
23
22
206
196
26
25
10
9
Appendix
Table D.5 : Corruption difficulty. Mean RD across 26 models, ranked by the FP32 four-dataset average. F32/I8 denote precision; † marks geometry-altering corruptions evaluated on kept ground truth.
Corruption
SHA
SHB
QNRF
JHU
clean (no corruption)
67.4
11.4
95.8
68.9
Sensor & exposure
fixed-pattern noise
102.6
28.5
141.0
103.9
Gaussian noise
99.8
33.4
155.6
117.5
highlight clipping
121.1
38.3
179.5
109.4
low light
93.0
38.0
141.5
101.0
Appendix
Table D.6 : mCE reference errors. Three-severity mean evaluated MAE (using kept-annotation normalization where applicable) of CSRNet at FP32 for each corruption and dataset. Each model’s mCE is normalized by the CSRNet reference at the same dataset and precision; the FP16 and INT8 references are obtained analogously and are omitted for brevity. The clean row reports the uncorrupted MAE.
Output representation
n
Environment
Optics & motion
Sensor & exposure
Encoding & transport
Scene clutter
Visibility loss
D Density map
15
38.2
60.4
68.7
38.0
14.9
22.4
B Blockwise count map
5
44.2
56.9
53.6
26.7
19.9
25.5
P Localization-oriented
4
51.0
66.3
86.8
32.0
11.9
21.8
C Direct count
2
27.7
37.3
20.8
18.2
17.4
22.5
Appendix
Table D.7 : FP32 relative degradation by output representation. Median RD by corruption family for each representation group; bold indicates the lowest median. Results are descriptive, and the direct-count group contains two Transcrowd variants.
Data
Q
clean
mean Δ
med.
p90
RD
Δ nMAE
SHA
S
24.1
6.3
2.0
27.9
26.2
4.4
M
43.8
7.7
2.9
42.8
17.7
3.2
D
60.0
13.0
5.0
66.1
21.7
3.4
VD
125.8
33.4
12.0
142.9
26.5
3.7
SHB
S
2.7
3.8
1.3
12.0
141.1
10.1
M
5.2
5.5
2.0
19.0
105.0
8.0
Appendix
Table D.8 : FP32 robustness by crowd-size quartile. S/M/D/VD denote sparse, medium, dense, and very dense scenes. Statistics aggregate all models, corruptions, and severities; median and 90th-percentile values summarize the upper-tail behavior.
clean
F1 degradation
FP32 drop
Dataset
F1
FP32
FP16
INT8
precision
recall
SHA
0.726
0.034
0.033
0.032
0.030
0.036
SHB
0.826
0.051
0.051
0.050
0.003
0.088
QNRF
0.739
0.027
0.027
0.027
0.014
0.037
JHU
0.685
0.029
0.029
0.029
0.005
0.047
Appendix
Table D.9 : Localization degradation by dataset. Clean F1 and mean corruption-induced degradation for the four native-point models. FP32 precision and recall changes are reported separately; FP16 and INT8 show similar F1 degradation.
F1 degradation
FP32 drop
Family
FP32
FP16
INT8
precision
recall
Sensor & exposure
0.054
0.054
0.052
0.015
0.085
Optics & motion
0.034
0.034
0.034
-0.001
0.062
Environment
0.033
0.033
0.033
0.018
0.043
Encoding & transport
0.030
0.030
0.030
0.007
0.050
Scene clutter
0.026
0.026
0.025
0.030
0.021
Appendix
Table D.10 : Localization degradation by corruption family. Mean within-dataset F1 degradation for the four native-point models. FP32 precision and recall changes show that most families primarily reduce recall.
FP16
INT8
Corruption
med ΔRD
med ΔRD
med ∣Δ∣
p10
p90
largest comparison
Sensor & exposure
Gaussian noise
-0.03
+0.58
5.91
-13.2
+20.4
ZIP-Small / JHU
vignetting
+0.01
-0.55
2.80
-16.1
+4.6
ZIP-Small / SHB
highlight clipping
+0.01
-0.52
3.66
-12.8
+9.9
ZIP-Pico / SHB
low light
-0.01
-0.23
3.67
-14.1
+8.5
GCHF / SHB
Appendix
Table E.1 : Precision sensitivity by corruption. ΔRD across 104 paired model–dataset evaluations.
Figure E.1 : Corruption-specific INT8 robustness shifts. Distribution of ΔRD across 104 model–dataset evaluations for each corruption: dots denote medians, boxes the IQR, and whiskers the 10th–90th percentiles. The shaded band marks the FP16 control range ( ±0.99 percentage points); colors indicate corruption families.
FP32
FP16
INT8
Model
Par.
INT8
J/img
img/s
J/img
img/s
J/img
img/s
(M)
%lyr †
CNN–based
APGCC
18.7
94
2.49
9.6
1.17
18.3
0.66
23.6
CHF
21.5
100
2.36
10.4
1.07
20.7
0.52
29.1
GCHF
21.5
100
2.37
10.4
1.07
20.7
0.52
29.1
Appendix
Table F.1 : Deployment performance on ShanghaiTech A. Energy and throughput for FP32, FP16, and INT8. Red marks INT8 regressions relative to FP16. † INT8 layer coverage is measured from A100-built engines and used only as a graph diagnostic.
FP32
FP16
INT8
Model
Par.
INT8
J/img
img/s
J/img
img/s
J/img
img/s
(M)
%lyr †
CNN–based
APGCC
18.7
94
3.35
7.3
1.53
14.1
0.86
18.1
CHF
21.5
100
3.54
7.1
1.59
14.5
0.73
20.9
GCHF
21.5
100
3.54
7.1
1.59
14.6
0.73
20.9
Appendix
Table F.2 : Deployment performance on ShanghaiTech B. Energy and throughput for FP32, FP16, and INT8. Red marks INT8 regressions relative to FP16. † INT8 layer coverage is measured from A100-built engines and used only as a graph diagnostic.
FP32
FP16
INT8
Model
Par.
INT8
J/img
img/s
J/img
img/s
J/img
img/s
(M)
%lyr †
CNN–based
APGCC
18.7
94
12.35
1.6
6.46
2.4
4.28
2.8
CHF
21.5
100
14.75
1.5
7.29
2.4
4.19
2.9
GCHF
21.5
100
14.74
1.5
7.23
2.4
4.16
2.9
Appendix
Table F.3 : Deployment performance on UCF-QNRF. Energy and throughput for FP32, FP16, and INT8. Red marks INT8 regressions relative to FP16. † INT8 layer coverage is measured from A100-built engines and used only as a graph diagnostic.
FP32
FP16
INT8
Model
Par.
INT8
J/img
img/s
J/img
img/s
J/img
img/s
(M)
%lyr †
CNN–based
APGCC
18.7
94
4.98
4.5
2.40
7.8
1.46
9.5
CHF
21.5
100
6.94
3.5
3.17
6.6
1.61
8.8
GCHF
21.5
100
7.01
3.5
3.18
6.6
1.59
9.0
Appendix
Table F.4 : Deployment performance on JHU-Crowd++. Energy and throughput for FP32, FP16, and INT8. Red marks INT8 regressions relative to FP16. † INT8 layer coverage is measured from A100-built engines and used only as a graph diagnostic.
Figure F.1 : Runtime decomposition. Four-dataset median stage times for five models with INT8 slowdowns and four faster controls; slowdown models are shown in red , and hatched bars denote INT8. The observed regressions are concentrated in GPU execution rather than transfer or dispatch.
Figure F.2 : INT8 coverage and engine diagnostics. Models are ordered by INT8 speedup over FP16; ∙ denotes an INT8 slowdown. Darker shading indicates greater structural risk, with R1–R5 defined in the text.
layers
plan layers (%)
Model
all
comp.
INT8
cov. (%)
INT8
FP16
FP32
build (s)
CHF
27
19
19
100.0
93
4
4
44
GCHF
27
19
19
100.0
93
4
4
40
CCST
349
63
63
100.0
43
47
10
136
CSRNet
23
17
17
100.0
91
4
4
11
DM-Count
34
19
19
100.0
75
21
4
14
Appendix
Table F.5 : INT8 layer census. Dataset-median A100 build-plan statistics for each model. Compute coverage is the fraction of arithmetic layers assigned to INT8; precision shares are computed over all plan layers. Values describe compiled graph structure rather than device execution.
Camouflaged object detection has improved substantially, but most standard benchmarks evaluate models only on clean images. This is not realistic because real cameras often capture blur, sensor noise, weather effects, and compression artifacts. We present COD10K-C, a corruption robustness benchmark based on COD10K. It includes 8 corruption types and 5 severity levels, giving 40 conditions and 81,040 evaluation pairs in total. We evaluate three popular camouflaged object detection models, SINet-v2, PFNet, and ZoomNet, as well as a lightweight model called RobustCODLite. All models show clear performance drops on corrupted images. Motion blur and Gaussian blur cause the largest drops, with SINet-v2 losing 18.5 Dice points under motion blur. Brightness and fog are less harmful. RobustCODLite uses corruption augmentation, a frequency-prior branch, and an uncertainty-consistency loss. It retains 92.3% of its clean Dice score under corruption, compared with 87.7% for SINet-v2, 84.8% for ZoomNet, and 84.1% for PFNet. On the hardest corruptions, RobustCODLite matches or outperforms models that perform better on clean data. We will release the COD10K-C GitHub repository to support future research in robust camouflaged object detection.
State-of-the-art crowd counting and localization are primarily modeled using two paradigms: density maps and point regression. Given the field's security ramifications, there is active interest in model robustness against adversarial attacks. Recent studies have demonstrated transferability across density-map-based approaches via adversarial patches, but cross-paradigm attacks (i.e., across both density map-based models and point regression-based models) remain unexplored. We introduce a novel adversarial framework that compromises both density map and point regression architectural paradigms through a comprehensive multi-task loss optimization. For point-regression models, we employ scene-density-specific high-confidence logit suppression; for density-map approaches, we use peak-targeted density map suppression. Both are combined with model-agnostic perceptual constraints to ensure that perturbations are effective and imperceptible to the human eye. Extensive experiments demonstrate the effectiveness of our attack, achieving on average a 7X increase in Mean Absolute Error compared to clean images while maintaining competitive visual quality, and successfully transferring across seven state-of-the-art crowd models with transfer ratios ranging from 0.55 to 1.69. Our approach strikes a balance between attack effectiveness and imperceptibility compared to state-of-the-art transferable attack strategies. The source code is available at https://github.com/simurgh7/CrowdGen
Deploying deep learning models on edge CPUs is bottlenecked by computational and memory constraints. Mixed-precision quantization promises to reduce inference latency while preserving accuracy. However, quantization affects different layer types in inconsistent ways, so identifying where accuracy loss is minimized and latency reduction is maximized is critical, as the effect accumulates over a full deployment into substantial savings or unacceptable task degradation. Such identification relies on sensitivity metrics, proxies that estimate layer-wise degradation without evaluating the task accuracy of every candidate policy. Nevertheless, widely used metrics fail systematically on modern architectures. We present a systematic empirical study of 13 sensitivity metrics for layer-wise INT8 quantization across four distinctly different neural networks, and validate the resulting policies on two ARM64 platforms. Gradient-based sensitivity methods fail on 4 out of 8 model-hardware configurations and weight-based statistics on 2. In contrast, the Jensen-Shannon Divergence achieves zero catastrophic failures, reliably isolating the layers that cannot be safely quantized. A sensitivity metric alone does not define a policy, and the fixed thresholds typically used for that step are fragile over the highly skewed distributions of modern architectures. We address this with K-Means clustering, achieving near-lossless accuracy and a mean speed-up of 1.81× over the full-precision model. Finally, we reveal that excluding from quantization the layers whose speed-up is negligible, regardless of their sensitivity, can be counterproductive, as it induces computational graph fragmentation and disables operator fusion. Our results yield concrete allocation policies for practitioners and researchers deploying quantized vision models on heterogeneous edge CPUs, without GPU access or gradient computation.
David Población-Criado, Dario Garcia-Gasulla, Eduardo Quinones
Barcelona Supercomputing Center (BSC) · Universitat Politècnica de Catalunya - BarcelonaTech (UPC)