To calculate the statistics, you first need to classify OK and NOK images by hand or using the ‘Class name by filename’ function. It is also possible to select multiple images at once using the ‘Shift’ key and classify them in bulk. After you submit your classification, click the ‘Show result’ button.
To be able to calculate all statistics, it is necessary to enable evaluation in any active module. If evaluation is not enabled, only the processing times are computed for annotated images.
Information in statistics
The statistics result shows a confusion matrix, which illustrates how the ‘predicted’ (evaluated by application) and ‘actual’ (annotated for statistics) results correspond (or not) to each other.
There can be 4 results, as shown in this image:
- True positive (TP) - user classified image as ‘Good’ and application evaluated image as ‘Good’
- False positive (FP) - user classified image as ‘Bad’ but application evaluated image as ‘Good’
- False negative (FN) - user classified image as ‘Good’ but application evaluated image as ‘Bad’
- True negative (TN) - user classified image as ‘Bad’ but application evaluated image as ‘Bad’
The matrix shows how many images ended up in each of those categories.
Next to the matrix is a table showing values for recall, precision and processing times (min, max and average).
Recall = TP / (TP + FN)
- What percentage of images classified as ‘Good’ by the user were evaluated as ‘Good’ by the application.
Precision = TP / (TP + FP)
- What percentage of images evaluated as ‘Good’ by the application were actually ‘Good’ (classified as ‘Good’ by the user).
After the statistics is successfully calculated, you can create an automatically generated report. The resulting report will be in HTML format. You can choose how many images (out of the ones classified in statistics) will be shown and whether you want to display only testing images (tick ‘Testing only’) or also training images.
The report shows the same information as Statistics result, plus training images (if you didn't tick the ‘Testing only’ option) and evaluated testing images. You can toggle whether rectangles and heatmaps should be shown on the evaluated images or not.