doctr.utils - docTR documentation (original) (raw)

This module regroups non-core features that are complementary to the rest of the package.

Visualization

Easy-to-use functions to make sense of your model’s predictions.

doctr.utils.visualization.visualize_page(page: dict[str, Any], image: ndarray, words_only: bool = True, display_artefacts: bool = True, scale: float = 10, interactive: bool = True, add_labels: bool = True, **kwargs: Any) → Figure[source]

Visualize a full page with predicted blocks, lines and words

import numpy as np import matplotlib.pyplot as plt from doctr.utils.visualization import visualize_page from doctr.models import ocr_db_crnn model = ocr_db_crnn(pretrained=True) input_page = (255 * np.random.rand(600, 800, 3)).astype(np.uint8) out = model([[input_page]]) visualize_page(out[0].pages[0].export(), input_page) plt.show()

Parameters:

Returns:

the matplotlib figure

Reconstitution

doctr.utils.reconstitution.synthesize_page(page: dict[str, Any], draw_proba: bool = False, font_family: str | None = None, smoothing_factor: float = 0.95, min_font_size: int = 8, max_font_size: int = 50) → ndarray[source]

Draw a the content of the element page (OCR response) on a blank page.

Parameters:

Returns:

the synthesized page

Task evaluation

Implementations of task-specific metrics to easily assess your model performances.

class doctr.utils.metrics.TextMatch[source]

Implements text match metric (word-level accuracy) for recognition task.

The raw aggregated metric is computed as follows:

\[\forall X, Y \in \mathcal{W}^N, TextMatch(X, Y) = \frac{1}{N} \sum\limits_{i=1}^N f_{Y_i}(X_i)\]

with the indicator function \(f_{a}\) defined as:

\[\begin{split}\forall a, x \in \mathcal{W}, f_a(x) = \left\{ \begin{array}{ll} 1 & \mbox{if } x = a \\ 0 & \mbox{otherwise.} \end{array} \right.\end{split}\]

where \(\mathcal{W}\) is the set of all possible character sequences,\(N\) is a strictly positive integer.

from doctr.utils import TextMatch metric = TextMatch() metric.update(['Hello', 'world'], ['hello', 'world']) metric.summary()

update(gt: list[str], pred: list[str]) → None[source]

Update the state of the metric with new predictions

Parameters:

summary() → dict[str, float][source]

Computes the aggregated metrics

Returns:

a dictionary with the exact match score for the raw data, its lower-case counterpart, its anyascii counterpart and its lower-case anyascii counterpart

class doctr.utils.metrics.LocalizationConfusion(iou_thresh: float = 0.5, use_polygons: bool = False)[source]

Implements common confusion metrics and mean IoU for localization evaluation.

The aggregated metrics are computed as follows:

\[\begin{split}\forall Y \in \mathcal{B}^N, \forall X \in \mathcal{B}^M, \\ Recall(X, Y) = \frac{1}{N} \sum\limits_{i=1}^N g_{X}(Y_i) \\ Precision(X, Y) = \frac{1}{M} \sum\limits_{i=1}^M g_{X}(Y_i) \\ meanIoU(X, Y) = \frac{1}{M} \sum\limits_{i=1}^M \max\limits_{j \in [1, N]} IoU(X_i, Y_j)\end{split}\]

with the function \(IoU(x, y)\) being the Intersection over Union between bounding boxes \(x\) and\(y\), and the function \(g_{X}\) defined as:

\[\begin{split}\forall y \in \mathcal{B}, g_X(y) = \left\{ \begin{array}{ll} 1 & \mbox{if } y\mbox{ has been assigned to any }(X_i)_i\mbox{ with an }IoU \geq 0.5 \\ 0 & \mbox{otherwise.} \end{array} \right.\end{split}\]

where \(\mathcal{B}\) is the set of possible bounding boxes,\(N\) (number of ground truths) and \(M\) (number of predictions) are strictly positive integers.

import numpy as np from doctr.utils import LocalizationConfusion metric = LocalizationConfusion(iou_thresh=0.5) metric.update(np.asarray([[0, 0, 100, 100]]), np.asarray([[0, 0, 70, 70], [110, 95, 200, 150]])) metric.summary()

Parameters:

update(gts: ndarray, preds: ndarray) → None[source]

Updates the metric

Parameters:

summary() → tuple[float | None, float | None, float | None][source]

Computes the aggregated metrics

Returns:

a tuple with the recall, precision and meanIoU scores

class doctr.utils.metrics.OCRMetric(iou_thresh: float = 0.5, use_polygons: bool = False)[source]

Implements an end-to-end OCR metric.

The aggregated metrics are computed as follows:

\[\begin{split}\forall (B, L) \in \mathcal{B}^N \times \mathcal{L}^N, \forall (\hat{B}, \hat{L}) \in \mathcal{B}^M \times \mathcal{L}^M, \\ Recall(B, \hat{B}, L, \hat{L}) = \frac{1}{N} \sum\limits_{i=1}^N h_{B,L}(\hat{B}_i, \hat{L}_i) \\ Precision(B, \hat{B}, L, \hat{L}) = \frac{1}{M} \sum\limits_{i=1}^M h_{B,L}(\hat{B}_i, \hat{L}_i) \\ meanIoU(B, \hat{B}) = \frac{1}{M} \sum\limits_{i=1}^M \max\limits_{j \in [1, N]} IoU(\hat{B}_i, B_j)\end{split}\]

with the function \(IoU(x, y)\) being the Intersection over Union between bounding boxes \(x\) and\(y\), and the function \(h_{B, L}\) defined as:

\[\begin{split}\forall (b, l) \in \mathcal{B} \times \mathcal{L}, h_{B,L}(b, l) = \left\{ \begin{array}{ll} 1 & \mbox{if } b\mbox{ has been assigned to a given }B_j\mbox{ with an } \\ & IoU \geq 0.5 \mbox{ and that for this assignment, } l = L_j\\ 0 & \mbox{otherwise.} \end{array} \right.\end{split}\]

where \(\mathcal{B}\) is the set of possible bounding boxes,\(\mathcal{L}\) is the set of possible character sequences,\(N\) (number of ground truths) and \(M\) (number of predictions) are strictly positive integers.

import numpy as np from doctr.utils import OCRMetric metric = OCRMetric(iou_thresh=0.5) metric.update(np.asarray([[0, 0, 100, 100]]), np.asarray([[0, 0, 70, 70], [110, 95, 200, 150]]), ['hello'], ['hello', 'world']) metric.summary()

Parameters:

update(gt_boxes: ndarray, pred_boxes: ndarray, gt_labels: list[str], pred_labels: list[str]) → None[source]

Updates the metric

Parameters:

summary() → tuple[dict[str, float | None], dict[str, float | None], float | None][source]

Computes the aggregated metrics

Returns:

a tuple with the recall & precision for each string comparison and the mean IoU

class doctr.utils.metrics.DetectionMetric(iou_thresh: float = 0.5, use_polygons: bool = False)[source]

Implements an object detection metric.

The aggregated metrics are computed as follows:

\[\begin{split}\forall (B, C) \in \mathcal{B}^N \times \mathcal{C}^N, \forall (\hat{B}, \hat{C}) \in \mathcal{B}^M \times \mathcal{C}^M, \\ Recall(B, \hat{B}, C, \hat{C}) = \frac{1}{N} \sum\limits_{i=1}^N h_{B,C}(\hat{B}_i, \hat{C}_i) \\ Precision(B, \hat{B}, C, \hat{C}) = \frac{1}{M} \sum\limits_{i=1}^M h_{B,C}(\hat{B}_i, \hat{C}_i) \\ meanIoU(B, \hat{B}) = \frac{1}{M} \sum\limits_{i=1}^M \max\limits_{j \in [1, N]} IoU(\hat{B}_i, B_j)\end{split}\]

with the function \(IoU(x, y)\) being the Intersection over Union between bounding boxes \(x\) and\(y\), and the function \(h_{B, C}\) defined as:

\[\begin{split}\forall (b, c) \in \mathcal{B} \times \mathcal{C}, h_{B,C}(b, c) = \left\{ \begin{array}{ll} 1 & \mbox{if } b\mbox{ has been assigned to a given }B_j\mbox{ with an } \\ & IoU \geq 0.5 \mbox{ and that for this assignment, } c = C_j\\ 0 & \mbox{otherwise.} \end{array} \right.\end{split}\]

where \(\mathcal{B}\) is the set of possible bounding boxes,\(\mathcal{C}\) is the set of possible class indices,\(N\) (number of ground truths) and \(M\) (number of predictions) are strictly positive integers.

import numpy as np from doctr.utils import DetectionMetric metric = DetectionMetric(iou_thresh=0.5) metric.update(np.asarray([[0, 0, 100, 100]]), np.asarray([[0, 0, 70, 70], [110, 95, 200, 150]]), np.zeros(1, dtype=np.int64), np.array([0, 1], dtype=np.int64)) metric.summary()

Parameters:

update(gt_boxes: ndarray, pred_boxes: ndarray, gt_labels: ndarray, pred_labels: ndarray) → None[source]

Updates the metric

Parameters:

summary() → tuple[float | None, float | None, float | None][source]

Computes the aggregated metrics

Returns:

a tuple with the recall & precision for each class prediction and the mean IoU