document image degradation

Overview

ocrodeg

The ocrodeg package is a small Python library implementing document image degradation for data augmentation for handwriting recognition and OCR applications.

The following illustrates the kinds of degradations available from ocrodeg.

%pylab inline
Populating the interactive namespace from numpy and matplotlib
rc("image", cmap="gray", interpolation="bicubic")
figsize(10, 10)
import scipy.ndimage as ndi
import ocrodeg

image = imread("testdata/W1P0.png")
imshow(image)
<matplotlib.image.AxesImage at 0x7fabcc7ab390>

png

PAGE ROTATION

This is just for illustration; for large page rotations, you can just use ndimage.

for i, angle in enumerate([0, 90, 180, 270]):
    subplot(2, 2, i+1)
    imshow(ndi.rotate(image, angle))

png

RANDOM GEOMETRIC TRANSFORMATIONS

random_transform generates random transformation parameters that work reasonably well for document image degradation. You can override the ranges used by each of these parameters by keyword arguments.

ocrodeg.random_transform()
{'angle': -0.016783842893063807,
 'aniso': 0.805280370671964,
 'scale': 0.9709145529604223,
 'translation': (0.014319657859164045, 0.03676897986267606)}

Here are four samples generated by random transforms.

for i in xrange(4):
    subplot(2, 2, i+1)
    imshow(ocrodeg.transform_image(image, **ocrodeg.random_transform()))

png

You can use transform_image directly with the different parameters to get a feel for the ranges and effects of these parameters.

for i, angle in enumerate([-2, -1, 0, 1]):
    subplot(2, 2, i+1)
    imshow(ocrodeg.transform_image(image, angle=angle*pi/180))

png

for i, angle in enumerate([-2, -1, 0, 1]):
    subplot(2, 2, i+1)
    imshow(ocrodeg.transform_image(image, angle=angle*pi/180)[1000:1500, 750:1250])

png

for i, aniso in enumerate([0.5, 1.0, 1.5, 2.0]):
    subplot(2, 2, i+1)
    imshow(ocrodeg.transform_image(image, aniso=aniso))

png

for i, aniso in enumerate([0.5, 1.0, 1.5, 2.0]):
    subplot(2, 2, i+1)
    imshow(ocrodeg.transform_image(image, aniso=aniso)[1000:1500, 750:1250])

png

for i, scale in enumerate([0.5, 0.9, 1.0, 2.0]):
    subplot(2, 2, i+1)
    imshow(ocrodeg.transform_image(image, scale=scale))

png

for i, scale in enumerate([0.5, 0.9, 1.0, 2.0]):
    subplot(2, 2, i+1)
    h, w = image.shape
    imshow(ocrodeg.transform_image(image, scale=scale)[h//2-200:h//2+200, w//3-200:w//3+200])

png

RANDOM DISTORTIONS

Pages often also have a small degree of warping. This can be modeled by random distortions. Very small and noisy random distortions also model ink spread, while large 1D random distortions model paper curl.

for i, sigma in enumerate([1.0, 2.0, 5.0, 20.0]):
    subplot(2, 2, i+1)
    noise = ocrodeg.bounded_gaussian_noise(image.shape, sigma, 5.0)
    distorted = ocrodeg.distort_with_noise(image, noise)
    h, w = image.shape
    imshow(distorted[h//2-200:h//2+200, w//3-200:w//3+200])

png

RULED SURFACE DISTORTIONS

for i, mag in enumerate([5.0, 20.0, 100.0, 200.0]):
    subplot(2, 2, i+1)
    noise = ocrodeg.noise_distort1d(image.shape, magnitude=mag)
    distorted = ocrodeg.distort_with_noise(image, noise)
    h, w = image.shape
    imshow(distorted[:1500])

png

BLUR, THRESHOLDING, NOISE

There are a range of utilities for modeling imaging artifacts: blurring, noise, inkspread.

patch = image[1900:2156, 1000:1256]
imshow(patch)
<matplotlib.image.AxesImage at 0x7fabc88c7e10>

png

for i, s in enumerate([0, 1, 2, 4]):
    subplot(2, 2, i+1)
    blurred = ndi.gaussian_filter(patch, s)
    imshow(blurred)

png

for i, s in enumerate([0, 1, 2, 4]):
    subplot(2, 2, i+1)
    blurred = ndi.gaussian_filter(patch, s)
    thresholded = 1.0*(blurred>0.5)
    imshow(thresholded)

png

reload(ocrodeg)
for i, s in enumerate([0.0, 1.0, 2.0, 4.0]):
    subplot(2, 2, i+1)
    blurred = ocrodeg.binary_blur(patch, s)
    imshow(blurred)

png

for i, s in enumerate([0.0, 0.1, 0.2, 0.3]):
    subplot(2, 2, i+1)
    blurred = ocrodeg.binary_blur(patch, 2.0, noise=s)
    imshow(blurred)

png

MULTISCALE NOISE

reload(ocrodeg)
for i in range(4):
    noisy = ocrodeg.make_multiscale_noise_uniform((512, 512))
    subplot(2, 2, i+1); imshow(noisy, vmin=0, vmax=1)

png

RANDOM BLOBS

for i, s in enumerate([2, 5, 10, 20]):
    subplot(2, 2, i+1)
    imshow(ocrodeg.random_blobs(patch.shape, 3e-4, s))

png

reload(ocrodeg)
blotched = ocrodeg.random_blotches(patch, 3e-4, 1e-4)
#blotched = minimum(maximum(patch, ocrodeg.random_blobs(patch.shape, 30, 10)), 1-ocrodeg.random_blobs(patch.shape, 15, 8))
subplot(121); imshow(patch); subplot(122); imshow(blotched)
<matplotlib.image.AxesImage at 0x7fabc8a35490>

png

FIBROUS NOISE

imshow(ocrodeg.make_fibrous_image((256, 256), 700, 300, 0.01))
<matplotlib.image.AxesImage at 0x7fabc8852450>

png

FOREGROUND / BACKGROUND SELECTION

subplot(121); imshow(patch); subplot(122); imshow(ocrodeg.printlike_multiscale(patch))
<matplotlib.image.AxesImage at 0x7fabc8676d90>

png

subplot(121); imshow(patch); subplot(122); imshow(ocrodeg.printlike_fibrous(patch))
<matplotlib.image.AxesImage at 0x7fabc8d1b250>

png

Owner
NVIDIA Research Projects
NVIDIA Research Projects
Simple SDF mesh generation in Python

Generate 3D meshes based on SDFs (signed distance functions) with a dirt simple Python API.

Michael Fogleman 1.1k Jan 08, 2023
docstrum

Docstrum Algorithm Getting Started This repo is for developing a Docstrum algorithm presented by O’Gorman (1993). Disclaimer This source code is built

Chulwoo Mike Pack 54 Dec 13, 2022
Code for the paper "Controllable Video Captioning with an Exemplar Sentence"

SMCG Code for the paper "Controllable Video Captioning with an Exemplar Sentence" Introduction We investigate a novel and challenging task, namely con

10 Dec 04, 2022
Fine tuning keras-ocr python package with custom synthetic dataset from scratch

OCR-Pipeline-with-Keras The keras-ocr package generally consists of two parts: a Detector and a Recognizer: Detector is responsible for creating bound

Eugene 1 Jan 05, 2022
Awesome anomaly detection in medical images

A curated list of awesome anomaly detection works in medical imaging, inspired by the other awesome-* initiatives.

Kang Zhou 57 Dec 19, 2022
This is a tensorflow re-implementation of PSENet: Shape Robust Text Detection with Progressive Scale Expansion Network.My blog:

PSENet: Shape Robust Text Detection with Progressive Scale Expansion Network Introduction This is a tensorflow re-implementation of PSENet: Shape Robu

Michael liu 498 Dec 30, 2022
Line based ATR Engine based on OCRopy

OCR Engine based on OCRopy and Kraken using python3. It is designed to both be easy to use from the command line but also be modular to be integrated

948 Dec 23, 2022
Fusion 360 Add-in that creates a pair of toothed curves that can be used to split a body and create two pieces that slide and lock together.

Fusion-360-Add-In-PuzzleSpline Fusion 360 Add-in that creates a pair of toothed curves that can be used to split a body and create two pieces that sli

Michiel van Wessem 1 Nov 15, 2021
The first open-source library that detects the font of a text in a image.

Typefont Typefont is an experimental library that detects the font of a text in a image. Usage Import the main function and invoke it like in the foll

Vasile Pește 1.6k Feb 24, 2022
Scene text recognition

AttentionOCR for Arbitrary-Shaped Scene Text Recognition Introduction This is the ranked No.1 tensorflow based scene text spotting algorithm on ICDAR2

777 Jan 09, 2023
EAST for ICPR MTWI 2018 Challenge II (Text detection of network images)

EAST_ICPR2018: EAST for ICPR MTWI 2018 Challenge II (Text detection of network images) Introduction This is a repository forked from argman/EAST for t

QichaoWu 49 Dec 24, 2022
Ocular is a state-of-the-art historical OCR system.

Ocular Ocular is a state-of-the-art historical OCR system. Its primary features are: Unsupervised learning of unknown fonts: requires only document im

228 Dec 30, 2022
基于图像识别的开源RPA工具,理论上可以支持所有windows软件和网页的自动化

SimpleRPA 基于图像识别的开源RPA工具,理论上可以支持所有windows软件和网页的自动化 简介 SimpleRPA是一款python语言编写的开源RPA工具(桌面自动控制工具),用户可以通过配置yaml格式的文件,来实现桌面软件的自动化控制,简化繁杂重复的工作,比如运营人员给用户发消息,

Song Hui 7 Jun 26, 2022
Text modding tools for FF7R (Final Fantasy VII Remake)

FF7R_text_mod_tools Subtitle modding tools for FF7R (Final Fantasy VII Remake) There are 3 tools I made. make_dualsub_mod.exe: Merges (or swaps) subti

10 Dec 19, 2022
Face Anonymizer - FaceAnonApp v1.0

Face Anonymizer - FaceAnonApp v1.0 Blur faces from image and video files in /data/files folder. Contents Repo of the source files for the FaceAnonApp.

6 Apr 18, 2022
Repository for playing the computer vision apps: People analytics on Raspberry Pi.

play-with-torch Repository for playing the computer vision apps: People analytics on Raspberry Pi. Tools Tested Hardware RasberryPi 4 Model B here, RA

eMHa 1 Sep 23, 2021
Sign Language Recognition service utilizing a deep learning model with Long Short-Term Memory to perform sign language recognition.

Sign Language Recognition Service This is a Sign Language Recognition service utilizing a deep learning model with Long Short-Term Memory to perform s

Martin Lønne 1 Jan 08, 2022
TextField: Learning A Deep Direction Field for Irregular Scene Text Detection (TIP 2019)

TextField: Learning A Deep Direction Field for Irregular Scene Text Detection Introduction The code and trained models of: TextField: Learning A Deep

Yukang Wang 101 Dec 12, 2022
nofacedb/faceprocessor is a face recognition engine for NoFaceDB program complex.

faceprocessor nofacedb/faceprocessor is a face recognition engine for NoFaceDB program complex. Tech faceprocessor uses a number of open source projec

NoFaceDB 3 Sep 06, 2021
3点クリックで円を指定し、極座標変換を行うサンプルプログラム

click-warpPolar 3点クリックで円を指定し、極座標変換を行うサンプルプログラムです。 Requirements OpenCV 3.4.2 or Later Usage 実行方法は以下です。 起動後、マウスで3点をクリックし円を指定してください。 python click-warpPol

KazuhitoTakahashi 17 Dec 30, 2022