Pre-processing Parameters Dialog

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Description

The Pre-processing parameters dialog allows to make some cleaning operations as well as the optimization of the image (the field area) to improve the recognition.

How to get it

Select the Pre-processing command from the Fields menu after placing on some field.

Options

- Invert colors
It allows to invert the field colors.

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Deskew

It is able to deskew the field as to the form.

-	Delete horizontal lines

It allows to delete the horizontal lines from a determined length. The way to convert centimeters into pixel is very simple: pixel = (cm / 2,54) * Resolution.
For instance, a 5 cm long line, having a resolution of 300, is: 5 / 2,54 * 300 = 590 pixel.
Lines are removed considering a tolerance of 2 white pixel: if there is dashed line with more of 2 pixel between one dash and another, it will not be removed.
In some case the line is upon a part of character, so the line removal damages the same character that will be remade automatically after the line removal.
The Ratio parameter shows the minimal relation (length/thickness) that the found element must have to be considered a line.
For example, it is supposed to have an image with a line consisting of 20 pixel long and 3 thick furthermore a box of 20x20 pixel. By setting the new parameter at 5, the line will be deleted (20/3=6.66>5) but not the square (20/20=1<5).

-	Delete vertical lines

It allows to delete vertical lines from a determined length. Use the same horizontal lines system to convert the centimeters into pixel.
If such as command is used into a barcodes field it needs to indicate carefully the right length so as to do not delete the whole code.
The Ratio parameter shows the minimal relation (length/thickness) that the found element must have to be considered a line.
For example, it is supposed to have an image with a line consisting of 20 pixel long and 3 thick furthermore a box of 20x20 pixel. By setting the new parameter at 5, the line will be deleted (20/3=6.66>5) but not the square (20/20=1<5)

-   Reconnect Crossed Characters
It allows to remake the character after using the delete lines option.

-   Delete Fields Box
Deletion of the box bigger in size than the specified one.
Use the same horizontal lines system to convert the centimeters into pixel.

-	Delete characters boxe

By selecting Delete Fields Box it is possible to specify the deletion of the boxes containing characters as well as the number of the boxes to delete.

- Delete Characters Box
By selecting Delete Field Box it is possible to specify the deletion of the characters separator and the number of the separators to delete.

- Delete Distanced Characters Separator
It allows to delete the distanced characters separator, their number and their max distance.

-	Delete intrusions

It allows to recognize characters inside of the boxes by deleting some possible intrusive lines into the boxes.

-	Delete Wires

It can clean the images from black lines.

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Despeckle

It can despeckle the image.

- Thin
If it is chosen this option the characters will be thinned. This feature is very useful if the characters inside of the files are particularly thick.

- Thik
If it is chosen this option the characters will be thickened. This feature is very useful if the characters inside of the files are not particularly thick.

- Delete small elements
All those smaller elements than the indicated size are deleted.

- Delete big elements
All those bigger elements than the indicated size are deleted.
Use the same horizontal lines system to convert the centimeters into pixel.


Notes

None.