Papers › Detecting Text in Natural Image with Connectionist Text Proposal Network

Detecting Text in Natural Image with Connectionist Text Proposal Network

12 Sep 2016arXiv:1609.03605archive 2025-07-28

Zhi Tian, Weilin Huang, Tong He, Pan He, Yu Qiao

We propose a novel Connectionist Text Proposal Network (CTPN) that accurately localizes text lines in natural image. The CTPN detects a text line in a sequence of fine-scale text proposals directly in convolutional feature maps. We develop a vertical anchor mechanism that jointly predicts location and text/non-text score of each fixed-width proposal, considerably improving localization accuracy. The sequential proposals are naturally connected by a recurrent neural network, which is seamlessly incorporated into the convolutional network, resulting in an end-to-end trainable model. This allows the CTPN to explore rich context information of image, making it powerful to detect extremely ambiguous text. The CTPN works reliably on multi-scale and multi- language text without further post-processing, departing from previous bottom-up methods requiring multi-step post-processing. It achieves 0.88 and 0.61 F-measure on the ICDAR 2013 and 2015 benchmarks, surpass- ing recent results [8, 35] by a large margin. The CTPN is computationally efficient with 0:14s/image, by using the very deep VGG16 model [27]. Online demo is available at: http://textdet.com/.

PaperPDFCodeCode Syntology ran

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

For agents, Syntology's MCP tool lists every function and class Syntology harvested from this paper and whether it ran (how to connect): get_harvested_code_for_paper(arxiv_id="1609.03605")

Code

Syntology Ran 3 of 35 code samples harvested from 8 repositories linked to this paper; 32 have no recorded run. Of those that ran: 1 ran · violated contract; 1 ran · our draft was wrong; 1 ran · fixture could not drive it.

By repository: community (archive-listed): 35 samples from 8 repositories, 3 ran. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

27 repositories listed; official and paper-mentioned ones first.

CrazySummerday/ctpn.pytorch mentioned on GitHubpytorchMIT report
JingJLiu/ICDAR2019.github.io mentioned on GitHub report
Sanster/tf_ctpn mentioned on GitHubtfMIT report
alorozco53/text-detection-ctpn mentioned on GitHubtfMIT report
courao/ocr.pytorch mentioned on GitHubpytorchMIT report
eragonruan/text-detection-ctpn mentioned on GitHubtfMIT report
eric4421/MTWI-2018 mentioned on GitHubpytorch report
lostsword/character_recognition mentioned on GitHubmindsporeApache-2.0 report
opconty/pytorch_ctpn mentioned on GitHubpytorch report
tranbahien/CTPN-TensorFlow mentioned on GitHubtf report
yangcan2017/text-detection-ctpn mentioned on GitHubtfMIT report
yunhai0920/company-name-id mentioned on GitHub report
zhaobomin/pytorch-ocr mentioned on GitHubpytorch report
zwenwang/CTPN_Pytorch mentioned on GitHubpytorch report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

35 samples harvested; 3 ran; 0 honoured the contract we drafted; 32 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

1ran · violated contract
1ran · our draft was wrong
1ran · fixture could not drive it
32unverified

Licence: 1 of the 35 samples is pointer only, meaning Syntology does not serve that copy's text. This page shows no code text for any sample; each one links to its file in the repository.

Harvested from 8 repositories linked to this paper, official or community; each sample names its own and says which. “Ran” means the sample executed on a synthesized input. It does not mean the output is correct, and nothing here reproduces the paper's results. “Honoured” and “violated” refer to a contract Syntology drafted from the code itself; “our draft was wrong” and “fixture could not drive it” are failures of Syntology's instrument, not of the code.

Each sample ends with its code_sha256, Syntology's identity for that exact code. An agent fetches the stored sample with Syntology's MCP tool get_code(code_sha256="…") (how to connect); click an identity to copy that call.

Repository labels, per sample. official repository: The archive marks this repository official for the paper. named in the paper: The archive records that the paper mentions this repository; it is not marked official. community (archive-listed): In the archive's code links for this paper, not marked official and not recorded as mentioned in the paper. found in paper text by Syntology: Syntology found this repository in the paper's own text; whether it is the authors' implementation is not asserted. community: Not in the archive's code links for this paper; a community repository Syntology harvested. Samples from a repository marked official are listed first. Licence labels name the repository's licence as recorded at harvest. “Pointer only” means Syntology does not serve that copy's text, for one of four reasons: no licence file was found; the licence was not identified; the licence is recorded as permissive but that copy's record is not marked cleared; or the licence is outside the permissive list Syntology serves text under (MIT, Apache-2.0, BSD and similar). Some licences outside that list permit redistribution, such as WTFPL, and GPL-3.0 under its conditions; they are simply not on the list. Hover a licence label for the reason. File links open the file on GitHub at the default branch, which may have changed since the harvest.

allowed_file HangZhouShuChengKeJi/text-detection-ctpn/main/web.py community (archive-listed) ran · violated contract MIT (permissive) · 9624be8c5b35939c · report
init_optimizer zhaobomin/pytorch-ocr/train_ctpn.py community (archive-listed) ran · our draft was wrong no licence file found · pointer only · 99b4d1927696d2e8 · report
voc_ap Sanster/tf_ctpn/lib/datasets/voc_eval.py community (archive-listed) ran · fixture could not drive it fingerprinted MIT (permissive) · 95c31c78be42f723 · report
addZeros lostsword/character_recognition/code/generate_dataset.py community (archive-listed) unverified Apache-2.0 (permissive) · 4334c57883b372a3 · report
bbox_transform Sanster/tf_ctpn/lib/model/bbox_transform.py community (archive-listed) unverified MIT (permissive) · 84dcf978d5570762 · report
bbox_transform alorozco53/text-detection-ctpn/lib/fast_rcnn/bbox_transform.py community (archive-listed) unverified MIT (permissive) · 7f1817340309b32e · report
bbox_transform_inv Sanster/tf_ctpn/lib/model/bbox_transform.py community (archive-listed) unverified MIT (permissive) · db910de1a7c014bc · report
bbox_transform_inv alorozco53/text-detection-ctpn/lib/fast_rcnn/bbox_transform.py community (archive-listed) unverified MIT (permissive) · d49676163bce1480 · report
bbox_transfrom CrazySummerday/ctpn.pytorch/ctpn/utils.py community (archive-listed) unverified MIT (permissive) · 24c53f3b46c06a72 · report
cal_iou courao/ocr.pytorch/detect/ctpn_utils.py community (archive-listed) unverified MIT (permissive) · f2bdee89194ccb33 · report
clip_boxes Sanster/tf_ctpn/lib/model/bbox_transform.py community (archive-listed) unverified MIT (permissive) · d24c99284beca7a6 · report
clip_boxes alorozco53/text-detection-ctpn/lib/text_connector/other.py community (archive-listed) unverified MIT (permissive) · 22b228f6941b5b16 · report
compute_iou CrazySummerday/ctpn.pytorch/ctpn/utils.py community (archive-listed) unverified MIT (permissive) · 5dfe6dd29f57f960 · report
conv3x3 courao/ocr.pytorch/recognize/crnn.py community (archive-listed) unverified MIT (permissive) · 938e4e638f594536 · report
create_label lostsword/character_recognition/code/ctpn/src/create_dataset.py community (archive-listed) unverified Apache-2.0 (permissive) · 965956d702b2c2ee · report
dumpRotateImage courao/ocr.pytorch/ocr.py community (archive-listed) unverified MIT (permissive) · a042b74b081841eb · report
find_in_path Sanster/tf_ctpn/lib/setup_cpu.py community (archive-listed) unverified MIT (permissive) · ca14946efd571693 · report
gen_anchor CrazySummerday/ctpn.pytorch/ctpn/utils.py community (archive-listed) unverified MIT (permissive) · 1b8bcc0ce345dcea · report
gen_anchor courao/ocr.pytorch/detect/ctpn_utils.py community (archive-listed) unverified MIT (permissive) · fc27893bf6fb8354 · report
generate_anchors Sanster/tf_ctpn/lib/layer_utils/generate_anchors.py community (archive-listed) unverified MIT (permissive) · 1ffc760a4459d409 · report
generate_anchors_pre Sanster/tf_ctpn/lib/layer_utils/generate_anchors.py community (archive-listed) unverified MIT (permissive) · 782e46a465c0d3f1 · report
get_char_nums lostsword/character_recognition/code/generate_dataset.py community (archive-listed) unverified Apache-2.0 (permissive) · 6121b647865394aa · report
get_imdb Sanster/tf_ctpn/lib/datasets/factory.py community (archive-listed) unverified MIT (permissive) · 3be9228820b46ef3 · report
get_imdb alorozco53/text-detection-ctpn/lib/datasets/factory.py community (archive-listed) unverified MIT (permissive) · e3d6d8098adf58aa · report
parse_rec Sanster/tf_ctpn/lib/datasets/voc_eval.py community (archive-listed) unverified MIT (permissive) · 0eafc51289a49033 · report
readxml CrazySummerday/ctpn.pytorch/ctpn/dataset.py community (archive-listed) unverified MIT (permissive) · 43aa0c2175ad6786 · report
resize courao/ocr.pytorch/detect/ctpn_utils.py community (archive-listed) unverified MIT (permissive) · 38401bcff05e1d84 · report
resize_im eragonruan/text-detection-ctpn/ctpn/demo_pb.py community (archive-listed) unverified MIT (permissive) · b9828f64fd08b6f3 · report
sort_box courao/ocr.pytorch/ocr.py community (archive-listed) unverified MIT (permissive) · 0bb4ac67d48f720d · report
strsort lostsword/character_recognition/code/generate_dataset.py community (archive-listed) unverified Apache-2.0 (permissive) · 74f85a99e9a1fa74 · report
threshold alorozco53/text-detection-ctpn/lib/text_connector/other.py community (archive-listed) unverified MIT (permissive) · d11f151f0452c0a7 · report
unique_boxes Sanster/tf_ctpn/lib/datasets/ds_utils.py community (archive-listed) unverified MIT (permissive) · 8a015c012f507631 · report
voc_eval Sanster/tf_ctpn/lib/datasets/voc_eval.py community (archive-listed) unverified MIT (permissive) · 7fc3942117603f02 · report
xywh_to_xyxy Sanster/tf_ctpn/lib/datasets/ds_utils.py community (archive-listed) unverified MIT (permissive) · d3e019b11b709edb · report
xyxy_to_xywh Sanster/tf_ctpn/lib/datasets/ds_utils.py community (archive-listed) unverified MIT (permissive) · a832e5017f504280 · report

Tasks

Scene Text Detection

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections