Segmentation

Specifies the polarity of the characters in the input image.

Specifies how the widths of characters in the font are expected to vary, which determines how character fragments should be merged or split.

Specifies the minimum width of a character’s character region, in pixels (1 - 1000; default = 3), that a character must have to be reported. This setting helps to filter background noise or other non-text features.

Specifies whether or not the function should account for the maximum allowable width of a character’s character region. This setting may be used to help the function determine if a character fragment should be split or merged. If the character fragment should be split, the Character Width Type parameter will determine the proper technique to be used.

Specifies the maximum allowable width of a character’s character region, in pixels (1 - 5000; default = 100).

Specifies the minimum height of a character’s character region, in pixels (1 - 1000; default = 3), that a character must have in order to be reported. This setting helps to filter background noise or other non-text features.

Specifies whether or not the function should account for the maximum allowable height of a character’s character region. This value is used in two ways: First, this value is used when finding the line, as a whole, e.g. to reject vertically adjacent noise, and/or other lines of vertically adjacent characters. Second, an individual character whose height exceeds this value will be trimmed to meet this height.

Specifies the maximum allowable height of a character’s character region, in pixels (1 - 5000; default = 100).

Specifies whether or not the function will account for the minimum allowable aspect ratio of a character, where the aspect ratio is defined as the height of the entire line of characters, divided by the width of the character’s character region.

Specifies the minimum allowable aspect ratio (0 - 500; default = 80) of a character. This setting may be used to indirectly set the maximum width of characters by using the overall height of the line of characters, where the maximum width equals the line height, divided by the Minimum Character Aspect Ratio value. Character fragments wider than allowed by this parameter will not be merged, and will be split to form two or more character fragments that are not too wide (which is controlled by the Character Width Type parameter).

Specifies the angel search range (0 - 45; default = 0), in degrees.

Specifies the skew search range (0 - 45; default = 0), in degrees.

Specifies how the function should merge character fragments when forming characters during segmentation. Determines whether or not two character fragments are required to overlap to be considered as a part of a character, or whether or not character fragments with a horizontal gap between them may be considered as part of a character.

Specifies the minimum fraction (0 - 100; default = 0) by which two character fragments must overlap each other horizontally, in order for the two character fragments to be considered as part of the same character. The default value (0) will merge any two character fragments that overlap by at least 1 pixel; larger values will require that the character fragments overlap more substantially. For applications where some character pairs are intentionally overlapped horizontally (also called kerning), or cases where the Refine stage cannot completely correct for rotation and/or skew (typically because of inconsistent printing), the default value is necessary.

Specifies the maximum horizontal gap size, in pixels (0 - 1000; default = 5), that can occur within a single character, even for damaged characters.

Specifies the minimum horizontal gap size, in pixels (0 - 1000; default = 0), that must occur between two character fragments to be belong to different characters. The gap is measured from the right edge of the character region of one character, to the left edge of the character region of the next character. If the gap between two fragments is smaller than this value, then the fragments must be considered to be part of the same character, unless the combined character would be too wide (as specified by the Maximum Character Width and/or Minimum Character Aspect Ratio parameters).

Specifies the minimum number of foreground (i.e. text) pixels (0 - 1000; default = 15) that a character fragment must have in order to be considered for possible inclusion in a character. When setting this value, it must be set so that is small enough to keep real pieces of text, while still being large enough to exclude small fragments from background noise. For dot-matrix text and/or text that contains small characters such as periods, a smaller value may be necessary. For solid stroke text, where the characters do not tend to break up into multiple, smaller pieces, a larger value may be necessary.

Specifies the minimum number of foreground (i.e. text) pixels (0 - 5000; default = 30) that a binarized character must have in order to be reported; characters with too few pixels will be discarded. This setting helps to filter background noise or other non-text features.

Specifies the mode used to normalize the image, which removes background variation to utilize all 256 greyscale values (0 - 255).

Specifies whether or not to remove everything from a normalized image that does not have the same stroke width as the as the rest of the image. This option can remove some types of non-text features, such as thin lines that might otherwise connect nearby characters. This option can also remove some low-contrast background variations that might otherwise exceed the binarization threshold and create false fragments and/or interconnect nearby characters. However, using this option may cause problems if the text does not have a consistent stroke width and/or the text has significant variable contrast (e.g. parts of some strokes are very faint).

Specifies whether or not the function will completely ignore any fragments that touch any border of the ROI. Ignoring such fragments can be useful for non-text features, such as the edges of labels, that might be included within the ROI.

Specifies a percentage modifier (0 - 100; default = 50) in the range that is used to compute the binarization threshold, in the normalized image, that binarizes the image between text and background. For example, the default setting of 50% would produce a binarization threshold of roughly 128 (on a 0-255 greyscale range), with 0 equaling Black on White text, and 100 equaling White on Black text. Using a value less than 50% alters the binarization threshold so that there is less text and more background, whereas using a value greater than 50% produces less background and more text. Typically, the default value will correctly binarize the image; however, in cases where there is background texture or other background variations, decreasing this value may help compensate for the background variations.

Specifies the minimum amount of contrast [in grayscale levels (0 - 255; default = 30)] of a fragment as a whole, relative to the threshold in the normalized image, in order to be considered for possible inclusion in a character. Each foreground pixel in a fragment is always guaranteed to meet the threshold, but if all of the pixels in a fragment are very close to the threshold, then the fragment is likely just noise, rather than text. A value of 0 will prevent low-contrast fragments from being rejected.

Specifies the distance, as a percentage of character height (0 - 1000; default = 0), that a fragment may be vertically removed from the "mainline" running horizontally through the text. Ordinarily, characters are expected to lie along a straight, horizontal line after being refined (the stage of compensating for angular orientation and skew). However, characters may sometimes exhibit "jitter," where there may be vertical drift of the characters' positions. With the default setting, these character fragments would be rejected because they do not lie along the "mainline" of characters. Increasing this parameter setting allows the function to keep fragments that do not lie along the "mainline" of characters.

Specifies the type of character analysis mode to perform to determine the optimal character segmentation. This parameter determines whether or not to perform additional analysis beyond the Group stage.

Specifies the minimum pitch, in pixels (0 - 1000; default = 0), that can occur between two characters, where the pitch is computed based on the Character Pitch Position parameter. If the pitch between two fragments is smaller than this, then they must be considered to be part of the same character, unless the combined character would be too wide (as specified by the Maximum Character Width and/or Minimum Character Aspect Ratio parameters).

Specifies how the pitch between two successive characters should be measured. Pitch is defined as the distance between (approximately) corresponding points on adjacent characters, and not the distance from the end of one character to the beginning of the next character (which is called the inter-character gap). For fixed-pitch fonts in which the characters have different widths, typically the pitch will have a consistent value only when using the appropriate pitch metric.

Specifies whether the spacing between successive characters has a single, fixed value, or varies, depending on the particular characters. Pitch is defined as the distance between (approximately) corresponding points on adjacent characters, and not the distance from the end of one character to the beginning of the next character (which is called the inter-character gap).

All graphical diagnostic data will be hidden, except when the cell containing the OCRMax function is highlighted in the spreadsheet.

Regions around rejected characters will be drawn in red, and the mainline of the text will be enclosed in a blue rectangle.

Example

Regions around kept fragments will be drawn in cyan, and the mainline of the text will be enclosed in a blue rectangle.

Example

Regions around rejected fragments will be drawn in yellow, and the mainline of the text will be enclosed in a blue rectangle.

Example

Regions will be drawn around kept characters (green), rejected characters (red), kept fragments (cyan), rejected fragments (yellow), the mainline of the text (blue) and the extended mainline of the text (magenta).