Psaltiki

Last modified: February 17, 2010

Contents

Create_PsaltikiPage

object Create_PsaltikiPage (int oligon_height = 0, int oligon_width = 0)

Operates on:Image [OneBit|RGB]
Returns:object
Category:Psaltiki
Defined in:preprocessing.py
Author:Daniel Jahns

Returns a PsaltikiPage class. In the GUI it also creates an icon for the object.

Preprocessing

correct_rotation

Image [OneBit|GreyScale] correct_rotation (int oligon_height = 0)

Operates on:Image [OneBit|GreyScale]
Returns:Image [OneBit|GreyScale]
Category:Psaltiki/Preprocessing
Defined in:preprocessing.py
Author:Christoph Dalitz

Corrects a possible rotation angle with the aid of skewed projections.

When the image is large, it is temporarily scaled down for performance reasons. The parameter oligon_height determines how much the image is scaled down: when it is larger than 3, the image is scaled down so that the resulting oligon height is 2. Thus if you want to suppress the downscaling, set oligon_height to one or zero.

preprocess

Image [OneBit] preprocess (int speckle_size = 3, Choice [median|closing|wspeckle|none] smoothing_method, bool correct_rotation = False, bool remove_copy_border = False)

Operates on:Image [OneBit]
Returns:Image [OneBit]
Category:Psaltiki/Preprocessing
Defined in:preprocessing.py
Author:Christine Pranzas

This is only a wrapper function for the other preprocessing plugins. It provides a convenient GUI to select preprocessing operations and run them all at once.

remove_copy_border

Image [OneBit] remove_copy_border (ChoiceString(strict) [size|black_area] feature = size)

Operates on:Image [OneBit|GreyScale|RGB]
Returns:Image [OneBit]
Category:Psaltiki/Preprocessing
Defined in:preprocessing.py
Author:Christoph Dalitz

Removes large CCs that are possibly black borders from scanning.

Depending on feature, large CCs are identified as follows:

size:
CCs with a height greater than the 20 times the median height or a width greater than 10 times the median width of all CCs with width/height > 3 (this median is an estimator for the oligon_width) are removed
black_area:
CCs with a black_area greater than 20 times the median black area are removed

smooth

Image [OneBit] smooth (int speckle_size = 3, Choice [median|closing|wspeckle] filter)

Operates on:Image [OneBit]
Returns:Image [OneBit]
Category:Psaltiki/Preprocessing
Defined in:preprocessing.py
Author:Christoph Dalitz

Smooth the image by first despeckling with speckle_size and then filtering out white speckles. The despeckling can be skipped by giving a zero speckle size. The filtering method depends on the option filter:

0: applies a median filter (rank(5))

1: closes the image with a 3x3 black structuring element.

2: like despeckle, but with white speckles