withoutBG Open Weights
Open weights · commercially permissiveLicense: Apache-2.0
U²-Net Human Segmentation
Open weights · commercially permissiveLicense: Apache-2.0

withoutBG Open-Weight Model vs u2net_human_seg

Quantitative comparison: 34 images scored against ground-truth mattes. Lower is better. Use the view controls on each row to switch between transparency, chroma key, and alpha matte on all outputs.

MetricwithoutBG Open-Weight Modelu2net_human_seg
MGE (Edge Quality)0.03911 ✓0.08689
MAE (Overall Accuracy)0.01241 ✓0.09628

Disclosure: withoutBG includes BiRefNet

withoutBG Open Weights and Pro Model API are routed pipelines. A classifier sends fine strands, soft detail and transparency to withoutBG's own matting model, and hard opaque objects, flat scenes and vehicles to BiRefNet (MIT license), which is part of the pipeline. On this page, 11 of 34 images went to BiRefNet. The table splits the scores by route: the first group is what withoutBG's own matting model handled.

ImagesMetricwithoutBG Open-Weight Modelu2net_human_seg
Routed to withoutBG matting (23)MAE0.00893 ✓0.04155
MGE (edges)0.02915 ✓0.05936
Routed to BiRefNet (11)MAE0.01969 ✓0.21072
MGE (edges)0.05993 ✓0.14443

Per-image averages, lower is better.

Original photo: autumn bouquet vase
Ground Truth alpha matte: autumn bouquet vase
Alpha matte
withoutBG Open-Weight Model alpha matte: autumn bouquet vase
Alpha matte
u2net_human_seg alpha matte: autumn bouquet vase
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.04103✓
MAE
0.00678✓
u2net_human_seg
MGE
0.18039
MAE
0.26527
Original photo: balcony flower planter bokeh
Ground Truth alpha matte: balcony flower planter bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: balcony flower planter bokeh
Alpha matte
u2net_human_seg alpha matte: balcony flower planter bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.05151✓
MAE
0.02894✓
u2net_human_seg
MGE
0.06967
MAE
0.22743
Original photo: balcony plant bokeh
Ground Truth alpha matte: balcony plant bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: balcony plant bokeh
Alpha matte
u2net_human_seg alpha matte: balcony plant bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.05343✓
MAE
0.00944✓
u2net_human_seg
MGE
0.09961
MAE
0.03528
Original photo: bearded man portrait
Ground Truth alpha matte: bearded man portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: bearded man portrait
Alpha matte
u2net_human_seg alpha matte: bearded man portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01719✓
MAE
0.00444✓
u2net_human_seg
MGE
0.04501
MAE
0.02340
Original photo: bike handlebar near beach
Ground Truth alpha matte: bike handlebar near beach
Alpha matte
withoutBG Open-Weight Model alpha matte: bike handlebar near beach
Alpha matte
u2net_human_seg alpha matte: bike handlebar near beach
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02392✓
MAE
0.00652✓
u2net_human_seg
MGE
0.08194
MAE
0.06321
Original photo: blowing dandelion seeds
Ground Truth alpha matte: blowing dandelion seeds
Alpha matte
withoutBG Open-Weight Model alpha matte: blowing dandelion seeds
Alpha matte
u2net_human_seg alpha matte: blowing dandelion seeds
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.04106✓
MAE
0.01152✓
u2net_human_seg
MGE
0.06375
MAE
0.03799
Original photo: campfire flames night
Ground Truth alpha matte: campfire flames night
Alpha matte
withoutBG Open-Weight Model alpha matte: campfire flames night
Alpha matte
u2net_human_seg alpha matte: campfire flames night
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03247✓
MAE
0.01071✓
u2net_human_seg
MGE
0.05262
MAE
0.06527
Original photo: cargo ebike park tracks
Ground Truth alpha matte: cargo ebike park tracks
Alpha matte
withoutBG Open-Weight Model alpha matte: cargo ebike park tracks
Alpha matte
u2net_human_seg alpha matte: cargo ebike park tracks
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.07023✓
MAE
0.01136✓
u2net_human_seg
MGE
0.19185
MAE
0.24021
Original photo: compound leaf raindrops
Ground Truth alpha matte: compound leaf raindrops
Alpha matte
withoutBG Open-Weight Model alpha matte: compound leaf raindrops
Alpha matte
u2net_human_seg alpha matte: compound leaf raindrops
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02835✓
MAE
0.00423✓
u2net_human_seg
MGE
0.08905
MAE
0.11216
Original photo: confetti sunset portrait
Ground Truth alpha matte: confetti sunset portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: confetti sunset portrait
Alpha matte
u2net_human_seg alpha matte: confetti sunset portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02826✓
MAE
0.00782✓
u2net_human_seg
MGE
0.05164
MAE
0.02787
Original photo: cyclist motion blur field
Ground Truth alpha matte: cyclist motion blur field
Alpha matte
withoutBG Open-Weight Model alpha matte: cyclist motion blur field
Alpha matte
u2net_human_seg alpha matte: cyclist motion blur field
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.04685✓
MAE
0.00925✓
u2net_human_seg
MGE
0.09263
MAE
0.05819
Original photo: dried flowers clay vase
Ground Truth alpha matte: dried flowers clay vase
Alpha matte
withoutBG Open-Weight Model alpha matte: dried flowers clay vase
Alpha matte
u2net_human_seg alpha matte: dried flowers clay vase
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.06053✓
MAE
0.01170✓
u2net_human_seg
MGE
0.10398
MAE
0.03386
Original photo: elderly man running blur
Ground Truth alpha matte: elderly man running blur
Alpha matte
withoutBG Open-Weight Model alpha matte: elderly man running blur
Alpha matte
u2net_human_seg alpha matte: elderly man running blur
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02119✓
MAE
0.00506✓
u2net_human_seg
MGE
0.03566
MAE
0.01279
Original photo: grass seed stem bokeh
Ground Truth alpha matte: grass seed stem bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: grass seed stem bokeh
Alpha matte
u2net_human_seg alpha matte: grass seed stem bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.04161✓
MAE
0.01017✓
u2net_human_seg
MGE
0.07784
MAE
0.02957
Original photo: hanging plant window
Ground Truth alpha matte: hanging plant window
Alpha matte
withoutBG Open-Weight Model alpha matte: hanging plant window
Alpha matte
u2net_human_seg alpha matte: hanging plant window
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.05709✓
MAE
0.01017✓
u2net_human_seg
MGE
0.16755
MAE
0.20554
Original photo: messy bun cityscape
Ground Truth alpha matte: messy bun cityscape
Alpha matte
withoutBG Open-Weight Model alpha matte: messy bun cityscape
Alpha matte
u2net_human_seg alpha matte: messy bun cityscape
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02022✓
MAE
0.00706✓
u2net_human_seg
MGE
0.05299
MAE
0.03977
Original photo: messy hair bearded portrait
Ground Truth alpha matte: messy hair bearded portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: messy hair bearded portrait
Alpha matte
u2net_human_seg alpha matte: messy hair bearded portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01419✓
MAE
0.00564✓
u2net_human_seg
MGE
0.04393
MAE
0.03770
Original photo: orange berries branch
Ground Truth alpha matte: orange berries branch
Alpha matte
withoutBG Open-Weight Model alpha matte: orange berries branch
Alpha matte
u2net_human_seg alpha matte: orange berries branch
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.08276✓
MAE
0.02340✓
u2net_human_seg
MGE
0.17383
MAE
0.37089
Original photo: red flower balcony bokeh
Ground Truth alpha matte: red flower balcony bokeh
Alpha matte
withoutBG Open-Weight Model alpha matte: red flower balcony bokeh
Alpha matte
u2net_human_seg alpha matte: red flower balcony bokeh
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.04719✓
MAE
0.01842✓
u2net_human_seg
MGE
0.07626
MAE
0.05722
Original photo: small fishing boat bw
Ground Truth alpha matte: small fishing boat bw
Alpha matte
withoutBG Open-Weight Model alpha matte: small fishing boat bw
Alpha matte
u2net_human_seg alpha matte: small fishing boat bw
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02469✓
MAE
0.00504✓
u2net_human_seg
MGE
0.08966
MAE
0.32712
Original photo: smiling man seaside sunset
Ground Truth alpha matte: smiling man seaside sunset
Alpha matte
withoutBG Open-Weight Model alpha matte: smiling man seaside sunset
Alpha matte
u2net_human_seg alpha matte: smiling man seaside sunset
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01337✓
MAE
0.00710✓
u2net_human_seg
MGE
0.02200
MAE
0.01058
Original photo: smiling woman seaside
Ground Truth alpha matte: smiling woman seaside
Alpha matte
withoutBG Open-Weight Model alpha matte: smiling woman seaside
Alpha matte
u2net_human_seg alpha matte: smiling woman seaside
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02154✓
MAE
0.00550✓
u2net_human_seg
MGE
0.04587
MAE
0.02406
Original photo: spoked bike wheel
Ground Truth alpha matte: spoked bike wheel
Alpha matte
withoutBG Open-Weight Model alpha matte: spoked bike wheel
Alpha matte
u2net_human_seg alpha matte: spoked bike wheel
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03721✓
MAE
0.00546✓
u2net_human_seg
MGE
0.12973
MAE
0.23347
Original photo: sprinter motion blur
Ground Truth alpha matte: sprinter motion blur
Alpha matte
withoutBG Open-Weight Model alpha matte: sprinter motion blur
Alpha matte
u2net_human_seg alpha matte: sprinter motion blur
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03279✓
MAE
0.02348✓
u2net_human_seg
MGE
0.04527
MAE
0.04463
Original photo: street dancer studio pose
Ground Truth alpha matte: street dancer studio pose
Alpha matte
withoutBG Open-Weight Model alpha matte: street dancer studio pose
Alpha matte
u2net_human_seg alpha matte: street dancer studio pose
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02246✓
MAE
0.00368✓
u2net_human_seg
MGE
0.04340
MAE
0.00965
Original photo: street portrait man
Ground Truth alpha matte: street portrait man
Alpha matte
withoutBG Open-Weight Model alpha matte: street portrait man
Alpha matte
u2net_human_seg alpha matte: street portrait man
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01142✓
MAE
0.00267✓
u2net_human_seg
MGE
0.03144
MAE
0.01333
Original photo: sunset field portrait
Ground Truth alpha matte: sunset field portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: sunset field portrait
Alpha matte
u2net_human_seg alpha matte: sunset field portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02087✓
MAE
0.00589✓
u2net_human_seg
MGE
0.04789
MAE
0.03824
Original photo: tabby cat portrait
Ground Truth alpha matte: tabby cat portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: tabby cat portrait
Alpha matte
u2net_human_seg alpha matte: tabby cat portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02626✓
MAE
0.00684✓
u2net_human_seg
MGE
0.06552
MAE
0.03158
Original photo: terrier dog mugshot
Ground Truth alpha matte: terrier dog mugshot
Alpha matte
withoutBG Open-Weight Model alpha matte: terrier dog mugshot
Alpha matte
u2net_human_seg alpha matte: terrier dog mugshot
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03987✓
MAE
0.01721✓
u2net_human_seg
MGE
0.09699
MAE
0.11154
Original photo: two bikes field
Ground Truth alpha matte: two bikes field
Alpha matte
withoutBG Open-Weight Model alpha matte: two bikes field
Alpha matte
u2net_human_seg alpha matte: two bikes field
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.13077✓
MAE
0.09352✓
u2net_human_seg
MGE
0.15004
MAE
0.13050
Original photo: two gravel bikes park
Ground Truth alpha matte: two gravel bikes park
Alpha matte
withoutBG Open-Weight Model alpha matte: two gravel bikes park
Alpha matte
u2net_human_seg alpha matte: two gravel bikes park
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.09317✓
MAE
0.01618✓
u2net_human_seg
MGE
0.26149
MAE
0.19606
Original photo: windblown curly hair backpack
Ground Truth alpha matte: windblown curly hair backpack
Alpha matte
withoutBG Open-Weight Model alpha matte: windblown curly hair backpack
Alpha matte
u2net_human_seg alpha matte: windblown curly hair backpack
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.02545✓
MAE
0.00694✓
u2net_human_seg
MGE
0.05666
MAE
0.04061
Original photo: windblown curly portrait
Ground Truth alpha matte: windblown curly portrait
Alpha matte
withoutBG Open-Weight Model alpha matte: windblown curly portrait
Alpha matte
u2net_human_seg alpha matte: windblown curly portrait
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.03566✓
MAE
0.01269✓
u2net_human_seg
MGE
0.07874
MAE
0.08652
Original photo: woman street portrait glasses
Ground Truth alpha matte: woman street portrait glasses
Alpha matte
withoutBG Open-Weight Model alpha matte: woman street portrait glasses
Alpha matte
u2net_human_seg alpha matte: woman street portrait glasses
Alpha matte
Original
Ground Truth
withoutBG Open-Weight Model
MGE
0.01505✓
MAE
0.00707✓
u2net_human_seg
MGE
0.03927
MAE
0.03209

Methodology

  • Alpha mattes are grayscale masks encoding per-pixel foreground probability. They capture fine edge detail (hair, fur, semi-transparent regions) that binary masks discard.
  • Metrics are computed by comparing predicted mattes against a ground-truth reference: MGE measures edge sharpness and MAE measures pixel-level accuracy. Both are lower-is-better.
  • Scored images come from Bench v0, where every image has a ground-truth matte. The benchmark page has the full methodology and per-image scores for every model (CSV / JSON).