Struct TextRecognizer 

pub struct TextRecognizer { /* private fields */ }

OCR engine interface.

use tesseract_ocr_static::{Image, TextRecognizer};
use image::ImageReader;

let rgb = ImageReader::open("hello.txt").unwrap().decode().unwrap().into_rgb8();
let image = Image::from_rgb(rgb.width(), rgb.height(), rgb.as_raw()).unwrap();
let mut recognizer = TextRecognizer::new().unwrap();
let results = recognizer.recognize_text(&image).unwrap();
assert_eq!("Hello world", results.get_utf8_text().as_str());

Implementations

impl TextRecognizer

pub fn new() -> Result<Self, InitFailed>

Creates new text recognizer with the default data directory, default language (English), and default OCR engine mode (LSTM).

pub fn with_languages(languages: &CStr) -> Result<Self, InitFailed>

Creates new text recognizer with the specified languages.

Languages are specified by their three-letter ISO codes separated by ‘+’ symbol.

pub fn with_config(config: Config<'_, '_>) -> Result<Self, InitFailed>

Creates new text recognizer with the provided configuration.

pub fn recognize_text<'a>( &'a mut self, image: &Image, ) -> Result<RecognitionResults<'a>, RecognitionFailed>

Recognizes text in the provided image and returns an iterator over the results.

pub fn recognize_text_with_timeout<'a>( &'a mut self, image: &Image, timeout: Duration, ) -> Result<RecognitionResults<'a>, RecognitionFailed>

Recognizes text in the provided image and returns an iterator over the results.

Timeout is the max. time spent for text recognition.

pub fn recognize_text_with_monitor<'a, C>( &'a mut self, image: &Image, monitor: Monitor<C>, ) -> Result<RecognitionResults<'a>, RecognitionFailed>

Recognizes text in the provided image and returns an iterator over the results.

The monitor is used to track the progress and set the timeout.

pub fn recognize_text_in_rect<'a>( &'a mut self, image: &Image, rect: &Rectangle, ) -> Result<RecognitionResults<'a>, RecognitionFailed>

Recognizes text in the specified rectangle of the provided image and returns an iterator over the results.

pub fn recognize_text_in_rect_with_timeout<'a>( &'a mut self, image: &Image, rect: &Rectangle, timeout: Duration, ) -> Result<RecognitionResults<'a>, RecognitionFailed>

Recognizes text in the specified rectangle of the provided image and returns an iterator over the results.

Timeout is the max. time spent for text recognition.

pub fn recognize_text_in_rect_with_monitor<'a, C>( &'a mut self, image: &Image, rect: &Rectangle, monitor: Monitor<C>, ) -> Result<RecognitionResults<'a>, RecognitionFailed>

Recognizes text in the specified rectangle of the provided image and returns an iterator over the results.

The monitor is used to track the progress and set the timeout.

pub fn analyze_layout<'a>(&'a self, image: &Image) -> LayoutIter<'a>

Analyzes the text layout in the provided image and returns layout analysis results as an iterator.

If you only need layout, consider using LayoutAnalyzer that uses less memory.

pub fn num_dawgs(&self) -> u32

Returns the number of Directed Acyclic Word Graph (DAWG) in the dictionary.

Methods from Deref<Target = Tesseract>

pub fn data_dir(&self) -> &Path

Returns data directory.

pub fn ocr_engine_mode(&self) -> OcrEngineMode

Returns OCR engine mode.

pub fn page_segmentation_mode(&self) -> PageSegmentationMode

pub fn set_page_segmentation_mode(&mut self, mode: PageSegmentationMode)

pub fn set_source_resolution(&mut self, pixels_per_inch: u32)

pub fn set_min_orientation_margin(&mut self, margin: f64)

pub fn clear(&mut self)

pub fn clear_cache(&mut self)

pub fn clear_adaptive_classifier(&mut self)

pub fn set_variable( &mut self, name: &CStr, value: &CStr, ) -> Result<(), InvalidVariable>

Set tesseract variable.

How to improve text recognition?

There is a guide on how to improve text recognition: https://tesseract-ocr.github.io/tessdoc/ImproveQuality.html

Variables

Variable	Default value	Description
allow_blob_division	1	Use divisible blobs chopping
ambigs_debug_level	0	Debug level for unichar ambiguities
applybox_debug	1	Debug level
applybox_exposure_pattern	".exp"	Exposure value follows this pattern in the image filename. The name of the image files are expected to be in the form [lang].[fontname].exp[num].tif
applybox_learn_chars_and_char_frags_mode	0	Learn both character fragments (as is done in the special low exposure mode) as well as unfragmented characters.
applybox_learn_ngrams_mode	0	Each bounding box is assumed to contain ngrams. Only learn the ngrams whose outlines overlap horizontally.
applybox_page	0	Page number to apply boxes from
assume_fixed_pitch_char_segment	0	include fixed-pitch heuristics in char segmentation
bidi_debug	0	Debug level for BiDi
bland_unrej	0	unrej potential with no checks
certainty_scale	20	Certainty scaling factor
chop_center_knob	0.15	Split center adjustment
chop_centered_maxwidth	90	Width of (smaller) chopped blobs above which we don’t care that a chop is not near the center.
chop_debug	0	Chop debug
chop_enable	1	Chop enable
chop_good_split	50	Good split limit
chop_inside_angle	-50	Min Inside Angle Bend
chop_min_outline_area	2000	Min Outline Area
chop_min_outline_points	6	Min Number of Points on Outline
chop_new_seam_pile	1	Use new seam_pile
chop_ok_split	100	OK split limit
chop_overlap_knob	0.9	Split overlap adjustment
chop_same_distance	2	Same distance
chop_seam_pile_size	150	Max number of seams in seam_pile
chop_sharpness_knob	0.06	Split sharpness adjustment
chop_split_dist_knob	0.5	Split length adjustment
chop_split_length	10000	Split Length
chop_vertical_creep	0	Vertical creep
chop_width_change_knob	5	Width change adjustment
chop_x_y_weight	3	X / Y length weight
chs_leading_punct	"('`\""	Leading punctuation
chs_trailing_punct1	").,;:?!"	1st Trailing punctuation
chs_trailing_punct2	")'`\""	2nd Trailing punctuation
classify_adapt_feature_threshold	230	Threshold for good features during adaptive 0-255
classify_adapt_proto_threshold	230	Threshold for good protos during adaptive 0-255
classify_adapted_pruning_factor	2.5	Prune poor adapted results this much worse than best result
classify_adapted_pruning_threshold	-1	Threshold at which classify_adapted_pruning_factor starts
classify_bln_numeric_mode	0	Assume the input is numbers [0-9].
classify_char_norm_range	0.2	Character Normalization Range …
classify_character_fragments_garbage_certainty_threshold	-3	Exclude fragments that do not look like whole characters from training and adaption
classify_class_pruner_multiplier	15	Class Pruner Multiplier 0-255:
classify_class_pruner_threshold	229	Class Pruner Threshold 0-255
classify_cp_angle_pad_loose	45	Class Pruner Angle Pad Loose
classify_cp_angle_pad_medium	20	Class Pruner Angle Pad Medium
classify_cp_angle_pad_tight	10	CLass Pruner Angle Pad Tight
classify_cp_cutoff_strength	7	Class Pruner CutoffStrength:
classify_cp_end_pad_loose	0.5	Class Pruner End Pad Loose
classify_cp_end_pad_medium	0.5	Class Pruner End Pad Medium
classify_cp_end_pad_tight	0.5	Class Pruner End Pad Tight
classify_cp_side_pad_loose	2.5	Class Pruner Side Pad Loose
classify_cp_side_pad_medium	1.2	Class Pruner Side Pad Medium
classify_cp_side_pad_tight	0.6	Class Pruner Side Pad Tight
classify_debug_character_fragments	0	Bring up graphical debugging windows for fragments training
classify_debug_level	0	Classify debug level
classify_enable_adaptive_debugger	0	Enable match debugger
classify_enable_adaptive_matcher	1	Enable adaptive classifier
classify_enable_learning	1	Enable adaptive classifier
classify_font_name	"UnknownFont"	Default font name to be used in training
classify_integer_matcher_multiplier	10	Integer Matcher Multiplier 0-255:
classify_learn_debug_str	""	Class str to debug learning
classify_learning_debug_level	0	Learning Debug Level:
classify_max_certainty_margin	5.5	Veto difference between classifier certainties
classify_max_rating_ratio	1.5	Veto ratio between classifier ratings
classify_max_slope	2.41421	Slope above which lines are called vertical
classify_min_slope	0.414214	Slope below which lines are called horizontal
classify_misfit_junk_penalty	0	Penalty to apply when a non-alnum is vertically out of its expected textline position
classify_nonlinear_norm	0	Non-linear stroke-density normalization
classify_norm_adj_curl	2	Norm adjust curl …
classify_norm_adj_midpoint	32	Norm adjust midpoint …
classify_norm_method	1	Normalization Method …
classify_num_cp_levels	3	Number of Class Pruner Levels
classify_pico_feature_length	0.05	Pico Feature Length
classify_pp_angle_pad	45	Proto Pruner Angle Pad
classify_pp_end_pad	0.5	Proto Prune End Pad
classify_pp_side_pad	2.5	Proto Pruner Side Pad
classify_save_adapted_templates	0	Save adapted templates to a file
classify_use_pre_adapted_templates	0	Use pre-adapted classifier templates
conflict_set_I_l_1	"Il1[]"	Il1 conflict set
crunch_accept_ok	1	Use acceptability in okstring
crunch_debug	0	As it says
crunch_del_cert	-10	POTENTIAL crunch cert lt this
crunch_del_high_word	1.5	Del if word gt xht x this above bl
crunch_del_low_word	0.5	Del if word gt xht x this below bl
crunch_del_max_ht	3	Del if word ht gt xht x this
crunch_del_min_ht	0.7	Del if word ht lt xht x this
crunch_del_min_width	3	Del if word width lt xht x this
crunch_del_rating	60	POTENTIAL crunch rating lt this
crunch_early_convert_bad_unlv_chs	0	Take out ~^ early?
crunch_early_merge_tess_fails	1	Before word crunch?
crunch_include_numerals	0	Fiddle alpha figures
crunch_leave_accept_strings	0	Don’t pot crunch sensible strings
crunch_leave_lc_strings	4	Don’t crunch words with long lower case strings
crunch_leave_ok_strings	1	Don’t touch sensible strings
crunch_leave_uc_strings	4	Don’t crunch words with long lower case strings
crunch_long_repetitions	3	Crunch words with long repetitions
crunch_poor_garbage_cert	-9	crunch garbage cert lt this
crunch_poor_garbage_rate	60	crunch garbage rating lt this
crunch_pot_indicators	1	How many potential indicators needed
crunch_pot_poor_cert	-8	POTENTIAL crunch cert lt this
crunch_pot_poor_rate	40	POTENTIAL crunch rating lt this
crunch_rating_max	10	For adj length in rating per ch
crunch_small_outlines_size	0.6	Small if lt xht x this
crunch_terrible_garbage	1	As it says
crunch_terrible_rating	80	crunch rating lt this
dawg_debug_level	0	Set to 1 for general debug info, to 2 for more details, to 3 to see all the debug messages
debug_file	""	File to send tprintf output to
debug_fix_space_level	0	Contextual fixspace debug
debug_noise_removal	0	Debug reassignment of small outlines
debug_x_ht_level	0	Reestimate debug
devanagari_split_debugimage	0	Whether to create a debug image for split shiro-rekha process.
devanagari_split_debuglevel	0	Debug level for split shiro-rekha process.
disable_character_fragments	1	Do not include character fragments in the results of the classifier
doc_dict_certainty_threshold	-2.25	Worst certainty for words that can be inserted into the document dictionary
doc_dict_pending_threshold	0	Worst certainty for using pending dictionary
document_title	""	Title of output document (used for hOCR and PDF output)
dotproduct	"auto"	Function used for calculation of dot product
edges_boxarea	0.875	Min area fraction of grandchild for box
edges_childarea	0.5	Min area fraction of child outline
edges_children_count_limit	45	Max holes allowed in blob
edges_children_fix	0	Remove boxy parents of char-like children
edges_children_per_grandchild	10	Importance ratio for chucking outlines
edges_debug	0	turn on debugging for this module
edges_max_children_layers	5	Max layers of nested children inside a character outline
edges_max_children_per_outline	10	Max number of children inside a character outline
edges_min_nonhole	12	Min pixels for potential char in box
edges_patharea_ratio	40	Max lensq/area for acceptable child outline
edges_use_new_outline_complexity	0	Use the new outline complexity module
enable_noise_removal	1	Remove and conditionally reassign small outlines when they confuse layout analysis, determining diacritics vs noise
equationdetect_save_bi_image	0	Save input bi image
equationdetect_save_merged_image	0	Save the merged image
equationdetect_save_seed_image	0	Save the seed image
equationdetect_save_spt_image	0	Save special character image
file_type	".tif"	Filename extension
fixsp_done_mode	1	What constitutes done for spacing
fixsp_non_noise_limit	1	How many non-noise blbs either side?
fixsp_small_outlines_size	0.28	Small if lt xht x this
force_word_assoc	0	force associator to run regardless of what enable_assoc is. This is used for CJK where component grouping is necessary.
gapmap_big_gaps	1.75	xht multiplier
gapmap_debug	0	Say which blocks have tables
gapmap_no_isolated_quanta	0	Ensure gaps not less than 2quanta wide
gapmap_use_ends	0	Use large space at start and end of rows
hocr_char_boxes	0	Add coordinates for each character to hocr output
hocr_font_info	0	Add font info to hocr output
hyphen_debug_level	0	Debug level for hyphenated words.
interactive_display_mode	0	Run interactively?
invert_threshold	0.7	For lines with a mean confidence below this value, OCR is also tried with an inverted image
jpg_quality	85	Set JPEG quality level
language_model_debug_level	0	Language model debug level
language_model_min_compound_length	3	Minimum length of compound words
language_model_ngram_nonmatch_score	-40	Average classifier score of a non-matching unichar.
language_model_ngram_on	0	Turn on/off the use of character ngram model
language_model_ngram_order	8	Maximum order of the character ngram model
language_model_ngram_rating_factor	16	Factor to bring log-probs into the same range as ratings when multiplied by outline length
language_model_ngram_scale_factor	0.03	Strength of the character ngram model relative to the character classifier
language_model_ngram_small_prob	1e-06	To avoid overly small denominators use this as the floor of the probability returned by the ngram model.
language_model_ngram_space_delimited_language	1	Words are delimited by space
language_model_ngram_use_only_first_uft8_step	0	Use only the first UTF8 step of the given string when computing log probabilities.
language_model_penalty_case	0.1	Penalty for inconsistent case
language_model_penalty_chartype	0.3	Penalty for inconsistent character type
language_model_penalty_font	0	Penalty for inconsistent font
language_model_penalty_increment	0.01	Penalty increment
language_model_penalty_non_dict_word	0.15	Penalty for non-dictionary words
language_model_penalty_non_freq_dict_word	0.1	Penalty for words not in the frequent word dictionary
language_model_penalty_punc	0.2	Penalty for inconsistent punctuation
language_model_penalty_script	0.5	Penalty for inconsistent script
language_model_penalty_spacing	0.05	Penalty for inconsistent spacing
language_model_use_sigmoidal_certainty	0	Use sigmoidal score for certainty
language_model_viterbi_list_max_num_prunable	10	Maximum number of prunable (those for which PrunablePath() is true) entries in each viterbi list recorded in BLOB_CHOICEs
language_model_viterbi_list_max_size	500	Maximum size of viterbi lists recorded in BLOB_CHOICEs
load_bigram_dawg	1	Load dawg with special word bigrams.
load_freq_dawg	1	Load frequent word dawg.
load_number_dawg	1	Load dawg with number patterns.
load_punc_dawg	1	Load dawg with punctuation patterns.
load_system_dawg	1	Load system word dawg.
load_unambig_dawg	1	Load unambiguous word dawg.
log_level	2147483647	Logging level
lstm_choice_iterations	5	Sets the number of cascading iterations for the Beamsearch in lstm_choice_mode. Note that lstm_choice_mode must be set to a value greater than 0 to produce results.
lstm_choice_mode	0	Allows to include alternative symbols choices in the hOCR output. Valid input values are 0, 1 and 2. 0 is the default value. With 1 the alternative symbol choices per timestep are included. With 2 alternative symbol choices are extracted from the CTC process instead of the lattice. The choices are mapped per character.
lstm_rating_coefficient	5	Sets the rating coefficient for the lstm choices. The smaller the coefficient, the better are the ratings for each choice and less information is lost due to the cut off at 0. The standard value is 5
lstm_use_matrix	1	Use ratings matrix/beam search with lstm
matcher_avg_noise_size	12	Avg. noise blob length
matcher_bad_match_pad	0.15	Bad Match Pad (0-1)
matcher_clustering_max_angle_delta	0.015	Maximum angle delta for prototype clustering
matcher_debug_flags	0	Matcher Debug Flags
matcher_debug_level	0	Matcher Debug Level
matcher_debug_separate_windows	0	Use two different windows for debugging the matching: One for the protos and one for the features.
matcher_good_threshold	0.125	Good Match (0-1)
matcher_min_examples_for_prototyping	3	Reliable Config Threshold
matcher_perfect_threshold	0.02	Perfect Match (0-1)
matcher_permanent_classes_min	1	Min # of permanent classes
matcher_rating_margin	0.1	New template margin (0-1)
matcher_reliable_adaptive_result	0	Great Match (0-1)
matcher_sufficient_examples_for_prototyping	5	Enable adaption even if the ambiguities have not been seen
max_permuter_attempts	10000	Maximum number of different character choices to consider during permutation. This limit is especially useful when user patterns are specified, since overly generic patterns can result in dawg search exploring an overly large number of options.
merge_fragments_in_matrix	1	Merge the fragments in the ratings matrix and delete them after merging
min_characters_to_try	50	Specify minimum characters to try during OSD
min_orientation_margin	7	Min acceptable orientation margin
min_sane_x_ht_pixels	8	Reject any x-ht lt or eq than this
multilang_debug_level	0	Print multilang debug info.
noise_cert_basechar	-8	Hingepoint for base char certainty
noise_cert_disjoint	-1	Hingepoint for disjoint certainty
noise_cert_factor	0.375	Scaling on certainty diff from Hingepoint
noise_cert_punc	-3	Threshold for new punc char certainty
noise_maxperblob	8	Max diacritics to apply to a blob
noise_maxperword	16	Max diacritics to apply to a word
numeric_punctuation	".,"	Punct. chs expected WITHIN numbers
ocr_devanagari_split_strategy	0	Whether to use the top-line splitting process for Devanagari documents while performing ocr.
ok_repeated_ch_non_alphanum_wds	"-?*="	Allow NN to unrej
oldbl_corrfix	1	Improve correlation of heights
oldbl_dot_error_size	1.26	Max aspect ratio of a dot
oldbl_holed_losscount	10	Max lost before fallback line used
oldbl_xhfix	0	Fix bug in modes threshold for xheights
oldbl_xhfract	0.4	Fraction of est allowed in calc
outlines_2	"ij!?%\":;"	Non standard number of outlines
outlines_odd	"%| "	Non standard number of outlines
output_ambig_words_file	""	Output file for ambiguities found in the dictionary
page_separator	"\u{c}"	Page separator (default is form feed control character)
page_xml_level	0	Create the PAGE file on 0=line or 1=word level.
page_xml_polygon	1	Create the PAGE file with polygons instead of box values
pageseg_apply_music_mask	0	Detect music staff and remove intersecting components
pageseg_devanagari_split_strategy	0	Whether to use the top-line splitting process for Devanagari documents while performing page-segmentation.
paragraph_debug_level	0	Print paragraph debug info.
paragraph_text_based	1	Run paragraph detection on the post-text-recognition (more accurate)
pitsync_joined_edge	0.75	Dist inside big blob for chopping
pitsync_linear_version	6	Use new fast algorithm
pitsync_offset_freecut_fraction	0.25	Fraction of cut for free cuts
poly_allow_detailed_fx	0	Allow feature extractors to see the original outline
poly_debug	0	Debug old poly
poly_wide_objects_better	1	More accurate approx on wide things
preserve_interword_spaces	0	Preserve multiple interword spaces
prioritize_division	0	Prioritize blob division over chopping
quality_blob_pc	0	good_quality_doc gte good blobs limit
quality_char_pc	0.95	good_quality_doc gte good char limit
quality_min_initial_alphas_reqd	2	alphas in a good word
quality_outline_pc	1	good_quality_doc lte outline error limit
quality_rej_pc	0.08	good_quality_doc lte rejection limit
quality_rowrej_pc	1.1	good_quality_doc gte good char limit
rating_scale	1.5	Rating scaling factor
rej_1Il_trust_permuter_type	1	Don’t double check
rej_1Il_use_dict_word	0	Use dictword test
rej_alphas_in_number_perm	0	Extend permuter check
rej_trust_doc_dawg	0	Use DOC dawg in 11l conf. detector
rej_use_good_perm	1	Individual rejection control
rej_use_sensible_wd	0	Extend permuter check
rej_use_tess_accepted	1	Individual rejection control
rej_use_tess_blanks	1	Individual rejection control
rej_whole_of_mostly_reject_word_fract	0.85	if >this fract
repair_unchopped_blobs	1	Fix blobs that aren’t chopped
save_alt_choices	1	Save alternative paths found during chopping and segmentation search
save_doc_words	0	Save Document Words
segment_nonalphabetic_script	0	Don’t use any alphabetic-specific tricks. Set to true in the traineddata config file for scripts that are cursive or inherently fixed-pitch
segment_penalty_dict_case_bad	1.3125	Default score multiplier for word matches, which may have case issues (lower is better).
segment_penalty_dict_case_ok	1.1	Score multiplier for word matches that have good case (lower is better).
segment_penalty_dict_frequent_word	1	Score multiplier for word matches which have good case and are frequent in the given language (lower is better).
segment_penalty_dict_nonword	1.25	Score multiplier for glyph fragment segmentations which do not match a dictionary word (lower is better).
segment_penalty_garbage	1.5	Score multiplier for poorly cased strings that are not in the dictionary and generally look like garbage (lower is better).
segsearch_debug_level	0	SegSearch debug level
segsearch_max_char_wh_ratio	2	Maximum character width-to-height ratio
segsearch_max_futile_classifications	20	Maximum number of pain point classifications per chunk that did not result in finding a better word choice.
segsearch_max_pain_points	2000	Maximum number of pain points stored in the queue
speckle_large_max_size	0.3	Max large speckle size
speckle_rating_penalty	10	Penalty to add to worst rating for noise
stopper_allowable_character_badness	3	Max certainty variation allowed in a word (in sigma)
stopper_certainty_per_char	-0.5	Certainty to add for each dict char above small word size.
stopper_debug_level	0	Stopper debug level
stopper_no_acceptable_choices	0	Make AcceptableChoice() always return false. Useful when there is a need to explore all segmentations
stopper_nondict_certainty_base	-2.5	Certainty threshold for non-dict words
stopper_phase2_certainty_rejection_offset	1	Reject certainty offset
stopper_smallword_size	2	Size of dict word to be treated as non-dict word
stream_filelist	0	Stream a filelist from stdin
subscript_max_y_top	0.5	Maximum top of a character measured as a multiple of x-height above the baseline for us to reconsider whether it’s a subscript.
superscript_bettered_certainty	0.97	What reduction in badness do we think sufficient to choose a superscript over what we’d thought. For example, a value of 0.6 means we want to reduce badness of certainty by at least 40%
superscript_debug	0	Debug level for sub & superscript fixer
superscript_min_y_bottom	0.3	Minimum bottom of a character measured as a multiple of x-height above the baseline for us to reconsider whether it’s a superscript.
superscript_scaledown_ratio	0.4	A superscript scaled down more than this is unbelievably small. For example, 0.3 means we expect the font size to be no smaller than 30% of the text line font size.
superscript_worse_certainty	2	How many times worse certainty does a superscript position glyph need to be for us to try classifying it as a char with a different baseline?
suspect_accept_rating	-999.9	Accept good rating limit
suspect_constrain_1Il	0	UNLV keep 1Il chars rejected
suspect_level	99	Suspect marker level
suspect_rating_per_ch	999.9	Don’t touch bad rating limit
suspect_short_words	2	Don’t suspect dict wds longer than this
tess_bn_matching	0	Baseline Normalized Matching
tess_cn_matching	0	Character Normalized Matching
tessedit_adaption_debug	0	Generate and print debug information for adaption
tessedit_ambigs_training	0	Perform training for ambiguities
tessedit_bigram_debug	0	Amount of debug output for bigram correction.
tessedit_certainty_threshold	-2.25	Good blob limit
tessedit_char_blacklist	""	Blacklist of chars not to recognize
tessedit_char_unblacklist	""	List of chars to override tessedit_char_blacklist
tessedit_char_whitelist	""	Whitelist of chars to recognize
tessedit_class_miss_scale	0.00390625	Scale factor for features not used
tessedit_create_alto	0	Write .xml ALTO file
tessedit_create_boxfile	0	Output text with boxes
tessedit_create_hocr	0	Write .html hOCR output file
tessedit_create_lstmbox	0	Write .box file for LSTM training
tessedit_create_page_xml	0	Write .page.xml PAGE file
tessedit_create_pdf	0	Write .pdf output file
tessedit_create_tsv	0	Write .tsv output file
tessedit_create_txt	0	Write .txt output file
tessedit_create_wordstrbox	0	Write WordStr format .box output file
tessedit_debug_block_rejection	0	Block and Row stats
tessedit_debug_doc_rejection	0	Page stats
tessedit_debug_fonts	0	Output font info per char
tessedit_debug_quality_metrics	0	Output data to debug file
tessedit_display_outwords	0	Draw output words
tessedit_do_invert	1	Try inverted line image if necessary (deprecated, will be removed in release 6, use the ‘invert_threshold’ parameter instead)
tessedit_dont_blkrej_good_wds	0	Use word segmentation quality metric
tessedit_dont_rowrej_good_wds	0	Use word segmentation quality metric
tessedit_dump_choices	0	Dump char choices
tessedit_dump_pageseg_images	0	Dump intermediate images made during page segmentation
tessedit_enable_bigram_correction	1	Enable correction based on the word bigram dictionary.
tessedit_enable_dict_correction	0	Enable single word correction based on the dictionary.
tessedit_enable_doc_dict	1	Add words to the document dictionary
tessedit_fix_fuzzy_spaces	1	Try to improve fuzzy spaces
tessedit_fix_hyphens	1	Crunch double hyphens?
tessedit_flip_0O	1	Contextual 0O O0 flips
tessedit_font_id	0	Font ID to use or zero
tessedit_good_doc_still_rowrej_wd	1.1	rej good doc wd if more than this fraction rejected
tessedit_good_quality_unrej	1	Reduce rejection on good docs
tessedit_image_border	2	Rej blbs near image edge limit
tessedit_init_config_only	0	Only initialize with the config file. Useful if the instance is not going to be used for OCR but say only for layout analysis.
tessedit_load_sublangs	""	List of languages to load with this one
tessedit_lower_flip_hyphen	1.5	Aspect ratio dot/hyphen test
tessedit_make_boxes_from_boxes	0	Generate more boxes from boxed chars
tessedit_minimal_rej_pass1	0	Do minimal rejection on pass 1 output
tessedit_minimal_rejection	0	Only reject tess failures
tessedit_ocr_engine_mode	1	Which OCR engine(s) to run (Tesseract, LSTM, both). Defaults to loading and running the most accurate available.
tessedit_override_permuter	1	According to dict_word
tessedit_page_number	-1	-1 -> All pages, else specific page to process
tessedit_pageseg_mode	6	Page seg mode: 0=osd only, 1=auto+osd, 2=auto_only, 3=auto, 4=column, 5=block_vert, 6=block, 7=line, 8=word, 9=word_circle, 10=char,11=sparse_text, 12=sparse_text+osd, 13=raw_line (Values from PageSegMode enum in tesseract/publictypes.h)
tessedit_parallelize	0	Run in parallel where possible
tessedit_prefer_joined_punct	0	Reward punctuation joins
tessedit_preserve_blk_rej_perfect_wds	1	Only rej partially rejected words in block rejection
tessedit_preserve_min_wd_len	2	Only preserve wds longer than this
tessedit_preserve_row_rej_perfect_wds	1	Only rej partially rejected words in row rejection
tessedit_reject_bad_qual_wds	1	Reject all bad quality wds
tessedit_reject_block_percent	45	%rej allowed before rej whole block
tessedit_reject_doc_percent	65	%rej allowed before rej whole doc
tessedit_reject_mode	0	Rejection algorithm
tessedit_reject_row_percent	40	%rej allowed before rej whole row
tessedit_rejection_debug	0	Adaption debug
tessedit_resegment_from_boxes	0	Take segmentation and labeling from box file
tessedit_resegment_from_line_boxes	0	Conversion of word/line box file to char box file
tessedit_row_rej_good_docs	1	Apply row rejection to good docs
tessedit_tess_adaption_mode	39	Adaptation decision algorithm for tess
tessedit_test_adaption	0	Test adaption criteria
tessedit_timing_debug	0	Print timing stats
tessedit_train_from_boxes	0	Generate training data from boxed chars
tessedit_train_line_recognizer	0	Break input into lines and remap boxes if present
tessedit_truncate_wordchoice_log	10	Max words to keep in list
tessedit_unrej_any_wd	0	Don’t bother with word plausibility
tessedit_upper_flip_hyphen	1.8	Aspect ratio dot/hyphen test
tessedit_use_primary_params_model	0	In multilingual mode use params model of the primary language
tessedit_use_reject_spaces	1	Reject spaces?
tessedit_whole_wd_rej_row_percent	70	Number of row rejects in whole word rejects which prevents whole row rejection
tessedit_word_for_word	0	Make output have exactly one word per WERD
tessedit_write_block_separators	0	Write block separators in output
tessedit_write_images	0	Capture the image from the IPE
tessedit_write_params_to_file	""	Write all parameters to the given file.
tessedit_write_rep_codes	0	Write repetition char code
tessedit_write_unlv	0	Write .unlv output file
tessedit_zero_kelvin_rejection	0	Don’t reject ANYTHING AT ALL
tessedit_zero_rejection	0	Don’t reject ANYTHING
test_pt	0	Test for point
test_pt_x	100000	xcoord
test_pt_y	100000	ycoord
textonly_pdf	0	Create PDF with only one invisible text layer
textord_all_prop	0	All doc is proportial text
textord_ascheight_mode_fraction	0.08	Min pile height to make ascheight
textord_ascx_ratio_max	1.8	Max cap/xheight
textord_ascx_ratio_min	1.25	Min cap/xheight
textord_balance_factor	1	Ding rate for unbalanced char cells
textord_baseline_debug	0	Baseline debug level
textord_biased_skewcalc	1	Bias skew estimates with line length
textord_blockndoc_fixed	0	Attempt whole doc/block fixed pitch
textord_blocksall_fixed	0	Moan about prop blocks
textord_blocksall_prop	0	Moan about fixed pitch blocks
textord_blshift_maxshift	0	Max baseline shift
textord_blshift_xfraction	9.99	Min size of baseline shift
textord_chop_width	1.5	Max width before chopping
textord_chopper_test	0	Chopper is being tested.
textord_debug_baselines	0	Debug baseline generation
textord_debug_blob	0	Print test blob information
textord_debug_block	0	Block to do debug on
textord_debug_bugs	0	Turn on output related to bugs in tab finding
textord_debug_pitch_metric	0	Write full metric stuff
textord_debug_pitch_test	0	Debug on fixed pitch test
textord_debug_printable	0	Make debug windows printable
textord_debug_tabfind	0	Debug tab finding
textord_debug_xheights	0	Test xheight algorithms
textord_descheight_mode_fraction	0.08	Min pile height to make descheight
textord_descx_ratio_max	0.6	Max desc/xheight
textord_descx_ratio_min	0.25	Min desc/xheight
textord_disable_pitch_test	0	Turn off dp fixed pitch algorithm
textord_dotmatrix_gap	3	Max pixel gap for broken pixed pitch
textord_equation_detect	0	Turn on equation detector
textord_excess_blobsize	1.3	New row made if blob makes row this big
textord_expansion_factor	1	Factor to expand rows by in expand_rows
textord_fast_pitch_test	0	Do even faster pitch algorithm
textord_fix_makerow_bug	1	Prevent multiple baselines
textord_fix_xheight_bug	1	Use spline baseline
textord_force_make_prop_words	0	Force proportional word segmentation on all rows
textord_fp_chop_error	2	Max allowed bending of chop cells
textord_fpiqr_ratio	1.5	Pitch IQR/Gap IQR threshold
textord_heavy_nr	0	Vigorously remove noise
textord_initialasc_ile	0.9	Ile of sizes for xheight guess
textord_initialx_ile	0.75	Ile of sizes for xheight guess
textord_interpolating_skew	1	Interpolate across gaps
textord_linespace_iqrlimit	0.2	Max iqr/median for linespace
textord_lms_line_trials	12	Number of linew fits to do
textord_max_blob_overlaps	4	Max number of blobs a big blob can overlap
textord_max_noise_size	7	Pixel size of noise
textord_max_pitch_iqr	0.2	Xh fraction noise in pitch
textord_min_blob_height_fraction	0.75	Min blob height/top to include blob top into xheight stats
textord_min_blobs_in_row	4	Min blobs before gradient counted
textord_min_linesize	1.25	* blob height for initial linesize
textord_min_xheight	10	Min credible pixel xheight
textord_minxh	0.25	fraction of linesize for min xheight
textord_new_initial_xheight	1	Use test xheight mechanism
textord_no_rejects	0	Don’t remove noise blobs
textord_noise_area_ratio	0.7	Fraction of bounding box for noise
textord_noise_debug	0	Debug row garbage detector
textord_noise_hfract	0.015625	Height fraction to discard outlines as speckle noise
textord_noise_normratio	2	Dot to norm ratio for deletion
textord_noise_rejrows	1	Reject noise-like rows
textord_noise_rejwords	1	Reject noise-like words
textord_noise_rowratio	6	Dot to norm ratio for deletion
textord_noise_sizefraction	10	Fraction of size for maxima
textord_noise_sizelimit	0.5	Fraction of x for big t count
textord_noise_sncount	1	super norm blobs to save row
textord_noise_sxfract	0.4	xh fract width error for norm blobs
textord_noise_syfract	0.2	xh fract height error for norm blobs
textord_noise_translimit	16	Transitions for normal blob
textord_occupancy_threshold	0.4	Fraction of neighbourhood
textord_ocropus_mode	0	Make baselines for ocropus
textord_old_baselines	1	Use old baseline algorithm
textord_old_xheight	0	Use old xheight algorithm
textord_oldbl_debug	0	Debug old baseline generation
textord_oldbl_jumplimit	0.15	X fraction for new partition
textord_oldbl_merge_parts	1	Merge suspect partitions
textord_oldbl_paradef	1	Use para default mechanism
textord_oldbl_split_splines	1	Split stepped splines
textord_overlap_x	0.375	Fraction of linespace for good overlap
textord_parallel_baselines	1	Force parallel baselines
textord_pitch_range	2	Max range test on pitch
textord_pitch_rowsimilarity	0.08	Fraction of xheight for sameness
textord_pitch_scalebigwords	0	Scale scores on big words
textord_projection_scale	0.2	Ding rate for mid-cuts
textord_really_old_xheight	0	Use original wiseowl xheight
textord_restore_underlines	1	Chop underlines & put back
textord_show_blobs	0	Display unsorted blobs
textord_show_boxes	0	Display unsorted blobs
textord_show_expanded_rows	0	Display rows after expanding
textord_show_final_blobs	0	Display blob bounds after pre-ass
textord_show_final_rows	0	Display rows after final fitting
textord_show_initial_rows	0	Display row accumulation
textord_show_initial_words	0	Display separate words
textord_show_page_cuts	0	Draw page-level cuts
textord_show_parallel_rows	0	Display page correlated rows
textord_show_row_cuts	0	Draw row-level cuts
textord_single_height_mode	0	Script has no xheight, so use a single mode
textord_skew_ile	0.5	Ile of gradients for page skew
textord_skew_lag	0.02	Lag for skew on row accumulation
textord_skewsmooth_offset	4	For smooth factor
textord_skewsmooth_offset2	1	For smooth factor
textord_space_size_is_variable	0	If true, word delimiter spaces are assumed to have variable width, even though characters have fixed pitch.
textord_spacesize_ratioprop	2	Min ratio space/nonspace
textord_spline_medianwin	6	Size of window for spline segmentation
textord_spline_minblobs	8	Min blobs in each spline segment
textord_spline_shift_fraction	0.02	Fraction of line spacing for quad
textord_straight_baselines	0	Force straight baselines
textord_tabfind_aligned_gap_fraction	0.75	Fraction of height used as a minimum gap for aligned blobs.
textord_tabfind_find_tables	1	run table detection
textord_tabfind_force_vertical_text	0	Force using vertical text page mode
textord_tabfind_only_strokewidths	0	Only run stroke widths
textord_tabfind_show_finaltabs	0	Show tab vectors
textord_tabfind_show_images	0	Show image blobs
textord_tabfind_show_initialtabs	0	Show tab candidates
textord_tabfind_show_strokewidths	0	Show stroke widths
textord_tabfind_show_vlines	0	Debug line finding
textord_tabfind_vertical_text	1	Enable vertical detection
textord_tabfind_vertical_text_ratio	0.5	Fraction of textlines deemed vertical to use vertical page mode
textord_tablefind_recognize_tables	0	Enables the table recognizer for table layout and filtering.
textord_tabvector_vertical_box_ratio	0.5	Fraction of box matches required to declare a line vertical
textord_tabvector_vertical_gap_fraction	0.5	max fraction of mean blob width allowed for vertical gaps in vertical text
textord_test_landscape	0	Tests refer to land/port
textord_test_x	-2147483647	coord of test pt
textord_test_y	-2147483647	coord of test pt
textord_testregion_bottom	-1	Bottom edge of debug rectangle in Leptonica coords (bottom=0/top=height), with horizontal lines x/y-flipped
textord_testregion_left	-1	Left edge of debug reporting rectangle in Leptonica coords (bottom=0/top=height), with horizontal lines x/y-flipped
textord_testregion_right	2147483647	Right edge of debug rectangle in Leptonica coords (bottom=0/top=height), with horizontal lines x/y-flipped
textord_testregion_top	2147483647	Top edge of debug reporting rectangle in Leptonica coords (bottom=0/top=height), with horizontal lines x/y-flipped
textord_underline_offset	0.1	Fraction of x to ignore
textord_underline_threshold	0.5	Fraction of width occupied
textord_underline_width	2	Multiple of line_size for underline
textord_use_cjk_fp_model	0	Use CJK fixed pitch model
textord_width_limit	8	Max width of blobs to make rows
textord_words_def_fixed	0.016	Threshold for definite fixed
textord_words_def_prop	0.09	Threshold for definite prop
textord_words_default_maxspace	3.5	Max believable third space
textord_words_default_minspace	0.6	Fraction of xheight
textord_words_default_nonspace	0.2	Fraction of xheight
textord_words_definite_spread	0.3	Non-fuzzy spacing region
textord_words_initial_lower	0.25	Max initial cluster size
textord_words_initial_upper	0.15	Min initial cluster spacing
textord_words_maxspace	4	Multiple of xheight
textord_words_min_minspace	0.3	Fraction of xheight
textord_words_minlarge	0.75	Fraction of valid gaps needed
textord_words_pitchsd_threshold	0.04	Pitch sync threshold
textord_words_veto_power	5	Rows required to outvote a veto
textord_wordstats_smooth_factor	0.05	Smoothing gap stats
textord_xheight_error_margin	0.1	Accepted variation
textord_xheight_mode_fraction	0.4	Min pile height to make xheight
thresholding_debug	0	Debug the thresholding process
thresholding_kfactor	0.34	Factor for reducing threshold due to variance. This parameter is used by the Sauvola thresholding method. Normal range: 0.2-0.5
thresholding_method	0	Thresholding method: 0 = Otsu, 1 = LeptonicaOtsu, 2 = Sauvola
thresholding_score_fraction	0.1	Fraction of the max Otsu score. This parameter is used by the LeptonicaOtsu thresholding method. For standard Otsu use 0.0, otherwise 0.1 is recommended
thresholding_smooth_kernel_size	0	Size of convolution kernel applied to threshold array (to be multiplied by image DPI). Use 0 for no smoothing. This parameter is used by the LeptonicaOtsu thresholding method
thresholding_tile_size	0.33	Desired tile size (to be multiplied by image DPI). This parameter is used by the LeptonicaOtsu thresholding method
thresholding_window_size	0.33	Window size for measuring local statistics (to be multiplied by image DPI). This parameter is used by the Sauvola thresholding method
tosp_all_flips_fuzzy	0	Pass ANY flip to context?
tosp_block_use_cert_spaces	1	Only stat OBVIOUS spaces
tosp_debug_level	0	Debug data
tosp_dont_fool_with_small_kerns	-1	Limit use of xht gap with odd small kns
tosp_enough_small_gaps	0.65	Fract of kerns reqd for isolated row stats
tosp_enough_space_samples_for_median	3	or should we use mean
tosp_few_samples	40	No.gaps reqd with 1 large gap to treat as a table
tosp_flip_caution	0	Don’t autoflip kn to sp when large separation
tosp_flip_fuzz_kn_to_sp	1	Default flip
tosp_flip_fuzz_sp_to_kn	1	Default flip
tosp_force_wordbreak_on_punct	0	Force word breaks on punct to break long lines in non-space delimited langs
tosp_fuzzy_kn_fraction	0.5	New fuzzy kn alg
tosp_fuzzy_limit_all	1	Don’t restrict kn->sp fuzzy limit to tables
tosp_fuzzy_sp_fraction	0.5	New fuzzy sp alg
tosp_fuzzy_space_factor	0.6	Fract of xheight for fuzz sp
tosp_fuzzy_space_factor1	0.5	Fract of xheight for fuzz sp
tosp_fuzzy_space_factor2	0.72	Fract of xheight for fuzz sp
tosp_gap_factor	0.83	gap ratio to flip sp->kern
tosp_ignore_big_gaps	-1	xht multiplier
tosp_ignore_very_big_gaps	3.5	xht multiplier
tosp_improve_thresh	0	Enable improvement heuristic
tosp_init_guess_kn_mult	2.2	Thresh guess - mult kn by this
tosp_init_guess_xht_mult	0.28	Thresh guess - mult xht by this
tosp_kern_gap_factor1	2	gap ratio to flip kern->sp
tosp_kern_gap_factor2	1.3	gap ratio to flip kern->sp
tosp_kern_gap_factor3	2.5	gap ratio to flip kern->sp
tosp_large_kerning	0.19	Limit use of xht gap with large kns
tosp_max_sane_kn_thresh	5	Multiplier on kn to limit thresh
tosp_min_sane_kn_sp	1.5	Don’t trust spaces less than this time kn
tosp_narrow_aspect_ratio	0.48	narrow if w/h less than this
tosp_narrow_blobs_not_cert	1	Only stat OBVIOUS spaces
tosp_narrow_fraction	0.3	Fract of xheight for narrow
tosp_near_lh_edge	0	Don’t reduce box if the top left is non blank
tosp_old_sp_kn_th_factor	2	Factor for defining space threshold in terms of space and kern sizes
tosp_old_to_bug_fix	0	Fix suspected bug in old code
tosp_old_to_constrain_sp_kn	0	Constrain relative values of inter and intra-word gaps for old_to_method.
tosp_old_to_method	0	Space stats use prechopping?
tosp_only_small_gaps_for_kern	0	Better guess
tosp_only_use_prop_rows	1	Block stats to use fixed pitch rows?
tosp_only_use_xht_gaps	0	Only use within xht gap for wd breaks
tosp_pass_wide_fuzz_sp_to_context	0.75	How wide fuzzies need context
tosp_recovery_isolated_row_stats	1	Use row alone when inadequate cert spaces
tosp_redo_kern_limit	10	No.samples reqd to reestimate for row
tosp_rep_space	1.6	rep gap multiplier for space
tosp_row_use_cert_spaces	1	Only stat OBVIOUS spaces
tosp_row_use_cert_spaces1	1	Only stat OBVIOUS spaces
tosp_rule_9_test_punct	0	Don’t chng kn to space next to punct
tosp_sanity_method	1	How to avoid being silly
tosp_short_row	20	No.gaps reqd with few cert spaces to use certs
tosp_silly_kn_sp_gap	0.2	Don’t let sp minus kn get too small
tosp_stats_use_xht_gaps	1	Use within xht gap for wd breaks
tosp_table_fuzzy_kn_sp_ratio	3	Fuzzy if less than this
tosp_table_kn_sp_ratio	2.25	Min difference of kn & sp in table
tosp_table_xht_sp_ratio	0.33	Expect spaces bigger than this
tosp_threshold_bias1	0	how far between kern and space?
tosp_threshold_bias2	0	how far between kern and space?
tosp_use_pre_chopping	0	Space stats use prechopping?
tosp_use_xht_gaps	1	Use within xht gap for wd breaks
tosp_wide_aspect_ratio	0	wide if w/h less than this
tosp_wide_fraction	0.52	Fract of xheight for wide
unlv_tilde_crunching	0	Mark v.bad words for tilde crunch
unrecognised_char	"|"	Output char for unidentified blobs
use_ambigs_for_adaption	0	Use ambigs for deciding whether to adapt to a character
use_only_first_uft8_step	0	Use only the first UTF8 step of the given string when computing log probabilities.
user_defined_dpi	0	Specify DPI for input image
user_patterns_file	""	A filename of user-provided patterns.
user_patterns_suffix	""	A suffix of user-provided patterns located in tessdata.
user_words_file	""	A filename of user-provided words.
user_words_suffix	""	A suffix of user-provided words located in tessdata.
word_to_debug	""	Word for which stopper debug information should be printed to stdout
wordrec_debug_blamer	0	Print blamer debug messages
wordrec_debug_level	0	Debug level for wordrec
wordrec_display_segmentations	0	Display Segmentations (ScrollView)
wordrec_display_splits	0	Display splits
wordrec_enable_assoc	1	Associator Enable
wordrec_max_join_chunks	4	Max number of broken pieces to associate
wordrec_run_blamer	0	Try to set the blame for errors
wordrec_skip_no_truth_words	0	Only run OCR for words that had truth recorded in BlamerBundle
words_default_fixed_limit	0.6	Allowed size variance
words_default_fixed_space	0.75	Fraction of xheight
words_default_prop_nonspace	0.25	Fraction of xheight
words_initial_lower	0.5	Max initial cluster size
words_initial_upper	0.15	Min initial cluster spacing
x_ht_acceptance_tolerance	8	Max allowed deviation of blob top outside of font data
x_ht_min_change	8	Min change in xht before actually trying it
xheight_penalty_inconsistent	0.25	Score penalty (0.1 = 10%) added if an xheight is inconsistent.
xheight_penalty_subscripts	0.125	Score penalty (0.1 = 10%) added if there are subscripts or superscripts in a word, but it is otherwise OK.

pub fn set_debug_variable( &mut self, name: &CStr, value: &CStr, ) -> Result<(), InvalidVariable>

Set tesseract variable.

Includes debug variables.

See set_variable for more information.

pub fn get_variable_i32(&self, name: &CStr) -> Option<i32>

Get integer variable value.

pub fn get_variable_bool(&self, name: &CStr) -> Option<bool>

Get boolean variable value.

pub fn get_variable_f64(&self, name: &CStr) -> Option<f64>

Get floating point variable value.

pub fn get_variable_c_str<'a>(&'a self, name: &CStr) -> Option<&'a CStr>

Get string variable value.

pub fn read_config_file(&mut self, filename: &Path) -> Result<()>

Read variables from the configuration file.

Doesn’t include debug variables.

This is a re-implementation of the original library call that handles I/O errors and invalid variables.

pub fn read_debug_config_file(&mut self, filename: &Path) -> Result<()>

Read variables from the configuration file.

Includes debug variables.

This is a re-implementation of the original library call that handles I/O errors and invalid variables.

pub fn print_variables_to_file( &self, filename: &CStr, ) -> Result<(), WriteFailed>

Print all variables to a file.

Trait Implementations

impl Deref for TextRecognizer

type Target = Tesseract

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for TextRecognizer

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.