如何從影像文件中提取文字

如何在C#中使用Iron Tesseract

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在C#中使用Iron Tesseract是透過建立一個Read()方法。 這將使用Tesseract 5的優化引擎將文字圖像轉換為可搜尋的PDF。

IronOCR提供了一個直觀的API來使用客製化和優化的Tesseract 5,稱之為Iron Tesseract。 通過使用IronOCR和IronTesseract,您將能夠將文字和掃描的文件圖像轉換為文字和可搜尋的PDF。 該程式庫支援125種國際語言,並包括像條碼閱讀電腦視覺這樣的先進功能。

快速開始:設置IronTesseract配置在C#中

此範例展示如何使用特定設置配置IronTesseract並在一行程式碼中執行OCR。

  1. 使用NuGet套件管理器安裝https://www.nuget.org/packages/IronOcr

    PM > Install-Package IronOcr
  2. 複製並運行這段程式碼片段。

    var result = new IronOcr.IronTesseract { Language = IronOcr.OcrLanguage.English, Configuration = new IronOcr.TesseractConfiguration { ReadBarCodes = false, RenderSearchablePdf = true, WhiteListCharacters = "ABCabc123" } }.Read(new IronOcr.OcrInput("image.png"));
  3. 部署以在您的實時環境中測試

    今天就開始在您的專案中使用IronOCR,透過免費試用

    arrow pointer

我如何建立一個IronTesseract實例?

使用此程式碼初始化一個Tesseract物件:

:path=/static-assets/ocr/content-code-examples/how-to/irontesseract-initialize-irontesseract.cs
using IronOcr;

IronTesseract ocr = new IronTesseract();
Imports IronOcr

Dim ocr As New IronTesseract()
$vbLabelText   $csharpLabel

您可以通過選擇不同的語言、啟用條碼閱讀以及白名單/黑名單字元來自定義IronTesseract的行為。 IronOCR提供了全面的配置選項以微調您的OCR過程:

:path=/static-assets/ocr/content-code-examples/how-to/irontesseract-configure-irontesseract.cs
IronTesseract ocr = new IronTesseract
{
    Configuration = new TesseractConfiguration
    {
        ReadBarCodes = false,
        RenderHocr = true,
        TesseractVariables = null,
        WhiteListCharacters = null,
        BlackListCharacters = "`ë|^",
    },
    MultiThreaded = false,
    Language = OcrLanguage.English,
    EnableTesseractConsoleMessages = true, // False as default
};
Dim ocr As New IronTesseract With {
	.Configuration = New TesseractConfiguration With {
		.ReadBarCodes = False,
		.RenderHocr = True,
		.TesseractVariables = Nothing,
		.WhiteListCharacters = Nothing,
		.BlackListCharacters = "`ë|^"
	},
	.MultiThreaded = False,
	.Language = OcrLanguage.English,
	.EnableTesseractConsoleMessages = True
}
$vbLabelText   $csharpLabel

一旦配置好,您就可以使用Tesseract功能來讀取OcrInput物件。 OcrInput類提供了靈活的方法來載入各種輸入格式:

:path=/static-assets/ocr/content-code-examples/how-to/irontesseract-read.cs
IronTesseract ocr = new IronTesseract();

using OcrInput input = new OcrInput();
input.LoadImage("attachment.png");
OcrResult result = ocr.Read(input);
string text = result.Text;
Dim ocr As New IronTesseract()

Using input As New OcrInput()
	input.LoadImage("attachment.png")
	Dim result As OcrResult = ocr.Read(input)
	Dim text As String = result.Text
End Using
$vbLabelText   $csharpLabel

對於複雜的場景,您可以利用多執行緒功能同時處理多個文件,大大提高批處理操作的性能。

什麼是高級Tesseract配置變數?

IronOcr Tesseract介面允許通過IronOcr.TesseractConfiguration類全面控制Tesseract配置變數。 這些高級設置使您能夠為特定用例優化OCR性能,例如修正低質量掃描閱讀特定文件型別

如何在程式碼中使用Tesseract配置?

:path=/static-assets/ocr/content-code-examples/how-to/irontesseract-tesseract-configuration.cs
using IronOcr;
using System;

IronTesseract Ocr = new IronTesseract();

Ocr.Language = OcrLanguage.English;
Ocr.Configuration.PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd;

// Configure Tesseract Engine
Ocr.Configuration.TesseractVariables["tessedit_parallelize"] = false;

using var input = new OcrInput();
input.LoadImage("/path/file.png");

OcrResult Result = Ocr.Read(input);
Console.WriteLine(Result.Text);
Imports IronOcr
Imports System

Private Ocr As New IronTesseract()

Ocr.Language = OcrLanguage.English
Ocr.Configuration.PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd

' Configure Tesseract Engine
Ocr.Configuration.TesseractVariables("tessedit_parallelize") = False

Dim input = New OcrInput()
input.LoadImage("/path/file.png")

Dim Result As OcrResult = Ocr.Read(input)
Console.WriteLine(Result.Text)
$vbLabelText   $csharpLabel

IronOCR還提供了針對不同文件型別的專用配置。例如,當閱讀護照處理MICR支票時,您可以應用特定的預處理過濾器和區域檢測以提高準確性。

金融文件的範例配置:

:path=/static-assets/ocr/content-code-examples/how-to/iron-tesseract-6.cs
// Example: Configure for financial documents
IronTesseract ocr = new IronTesseract
{
    Language = OcrLanguage.English,
    Configuration = new TesseractConfiguration
    {
        PageSegmentationMode = TesseractPageSegmentationMode.SingleBlock,
        TesseractVariables = new Dictionary<string, object>
        {
            ["tessedit_char_whitelist"] = "0123456789.$,",
            ["textord_heavy_nr"] = false,
            ["edges_max_children_per_outline"] = 10
        }
    }
};

// Apply preprocessing filters for better accuracy
using OcrInput input = new OcrInput();
input.LoadPdf("financial-document.pdf");
input.Deskew();
input.EnhanceResolution(300);

OcrResult result = ocr.Read(input);
Imports IronOcr

' Example: Configure for financial documents
Dim ocr As New IronTesseract With {
    .Language = OcrLanguage.English,
    .Configuration = New TesseractConfiguration With {
        .PageSegmentationMode = TesseractPageSegmentationMode.SingleBlock,
        .TesseractVariables = New Dictionary(Of String, Object) From {
            {"tessedit_char_whitelist", "0123456789.$,"},
            {"textord_heavy_nr", False},
            {"edges_max_children_per_outline", 10}
        }
    }
}

' Apply preprocessing filters for better accuracy
Using input As New OcrInput()
    input.LoadPdf("financial-document.pdf")
    input.Deskew()
    input.EnhanceResolution(300)

    Dim result As OcrResult = ocr.Read(input)
End Using
$vbLabelText   $csharpLabel

所有Tesseract配置變數的完整列表是什麼?

這些可以使用IronTesseract.Configuration.TesseractVariables["key"] = value;設置。 配置變數允許您微調OCR行為,以便針對特定文件獲得最佳結果。 有關優化OCR性能的詳細指南,請參閱我們的快速OCR配置指南

0Use old baseline algorithm 0All doc is proportial text 0Debug on fixed pitch test 0Turn off dp fixed pitch algorithm 0Do even faster pitch algorithm 0Write full metric stuff 0Draw row-level cuts 0Draw page-level cuts 0Use correct answer for fixed/prop 0Attempt whole doc/block fixed pitch 0Display separate words 0Display separate words 0Display forced fixed pitch words 0Moan about prop blocks 0Moan about fixed pitch blocks 0Dump stats when moaning 0Do current test 0.08Fraction of xheight for sameness 0.5Max initial cluster size 0.15Min initial cluster spacing 0.25Fraction of xheight 0.75Fraction of xheight 0.6Allowed size variance 0.3Non-fuzzy spacing region 2.8Min ratio space/nonspace 2Min ratio space/nonspace 1.5Pitch IQR/Gap IQR threshold 0.2Xh fraction noise in pitch 0.5Min width of decent blobs 0.1Fraction of x to ignore 0Debug level for unichar ambiguities 0Classify debug level 1Normalization Method ... 0Matcher Debug Level 0Matcher Debug Flags 0Learning Debug Level: 1Min # of permanent classes 3Reliable Config Threshold 5Enable adaption even if the ambiguities have not been seen 230Threshold for good protos during adaptive 0-255 230Threshold for good features during adaptive 0-255 229Class Pruner Threshold 0-255 15Class Pruner Multiplier 0-255: 7Class Pruner CutoffStrength: 10Integer Matcher Multiplier 0-255: 0Set to 1 for general debug info, to 2 for more details, to 3 to see all the debug messages 0Debug level for hyphenated words. 2Size of dict word to be treated as non-dict word 0Stopper debug level 10Max words to keep in list 10000Maximum 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. 1Fix blobs that aren't chopped 0Chop debug 10000Split Length 2Same distance 6Min Number of Points on Outline 150Max number of seams in seam_pile -50Min Inside Angle Bend 2000Min Outline Area 90Width of (smaller) chopped blobs above which we don't care that a chop is not near the center. 3X / Y length weight 0Debug level for wordrec 4Max number of broken pieces to associate 0SegSearch debug level 2000Maximum number of pain points stored in the queue 0Language model debug level 8Maximum order of the character ngram model 10Maximum number of prunable (those for which PrunablePath() is true) entries in each viterbi list recorded in BLOB_CHOICEs 500Maximum size of viterbi lists recorded in BLOB_CHOICEs 3Minimum length of compound words 0Display Segmentations 6Page 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) 2Which OCR engine(s) to run (Tesseract, LSTM, both). Defaults to loading and running the most accurate available. 0Whether to use the top-line splitting process for Devanagari documents while performing page-segmentation. 0Whether to use the top-line splitting process for Devanagari documents while performing ocr. 0Debug level for BiDi 1Debug level 0Page number to apply boxes from 0Amount of debug output for bigram correction. 0Debug reassignment of small outlines 8Max diacritics to apply to a blob 16Max diacritics to apply to a word 0Reestimate debug 2alphas in a good word 39Adaptation decision algorithm for tess 0Print multilang debug info. 0Print paragraph debug info. 2Only preserve wds longer than this 10For adj length in rating per ch 1How many potential indicators needed 4Don't crunch words with long lower case strings 4Don't crunch words with long lower case strings 3Crunch words with long repetitions 1How many non-noise blbs either side? 1What constitues done for spacing 0Contextual fixspace debug 8Max allowed deviation of blob top outside of font data 8Min change in xht before actually trying it 0Debug level for sub & superscript fixer 85Set JPEG quality level 0Specify DPI for input image 50Specify minimum characters to try during OSD 0Rejection algorithm 2Rej blbs near image edge limit 8Reject any x-ht lt or eq than this -1-1 -> All pages, else specific page to process 1Run in parallel where possible 2Allows 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. 5Sets 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. 0Debug data 3or should we use mean 10No.samples reqd to reestimate for row 40No.gaps reqd with 1 large gap to treat as a table 20No.gaps reqd with few cert spaces to use certs 1How to avoid being silly 7Pixel size of noise 0Baseline debug level 10Fraction of size for maxima 16Transitions for normal blob 1super norm blobs to save row 0Use ambigs for deciding whether to adapt to a character 0Prioritize blob division over chopping 1Enable adaptive classifier 0Character Normalized Matching 0Baseline Normalized Matching 1Enable adaptive classifier 0Use pre-adapted classifier templates 0Save adapted templates to a file 0Enable match debugger 0Non-linear stroke-density normalization 0Bring up graphical debugging windows for fragments training 0Use two different windows for debugging the matching: One for the protos and one for the features. 0Assume the input is numbers [0-9]. 1Load system word dawg. 1Load frequent word dawg. 1Load unambiguous word dawg. 1Load dawg with punctuation patterns. 1Load dawg with number patterns. 1Load dawg with special word bigrams. 0Use only the first UTF8 step of the given string when computing log probabilities. 0Make AcceptableChoice() always return false. Useful when there is a need to explore all segmentations 0Don't use any alphabetic-specific tricks. Set to true in the traineddata config file for scripts that are cursive or inherently fixed-pitch 0Save Document Words 1Merge the fragments in the ratings matrix and delete them after merging 1Associator Enable 0force associator to run regardless of what enable_assoc is. This is used for CJK where component grouping is necessary. 1Chop enable 0Vertical creep 1Use new seam_pile 0include fixed-pitch heuristics in char segmentation 0Only run OCR for words that had truth recorded in BlamerBundle 0Print blamer debug messages 0Try to set the blame for errors 1Save alternative paths found during chopping and segmentation search 1Words are delimited by space 0Use sigmoidal score for certainty 0Take segmentation and labeling from box file 0Conversion of word/line box file to char box file 0Generate training data from boxed chars 0Generate more boxes from boxed chars 0Break input into lines and remap boxes if present 0Dump intermediate images made during page segmentation 1Try inverting the image in LSTMRecognizeWord 0Perform training for ambiguities 0Generate and print debug information for adaption 0Learn both character fragments (as is done in the special low exposure mode) as well as unfragmented characters. 0Each bounding box is assumed to contain ngrams. Only learn the ngrams whose outlines overlap horizontally. 0Draw output words 0Dump char choices 0Print timing stats 1Try to improve fuzzy spaces 0Don't bother with word plausibility 1Crunch double hyphens? 1Add words to the document dictionary 0Output font info per char 0Block and Row stats 1Enable correction based on the word bigram dictionary. 0Enable single word correction based on the dictionary. 1Remove and conditionally reassign small outlines when they confuse layout analysis, determining diacritics vs noise 0Do minimal rejection on pass 1 output 0Test adaption criteria 0Test for point 1Run paragraph detection on the post-text-recognition (more accurate) 1Use ratings matrix/beam search with lstm 1Reduce rejection on good docs 1Reject spaces? 0Add font info to hocr output 0Add coordinates for each character to hocr output 1Before word crunch? 0Take out ~^ early? 1As it says 1Don't touch sensible strings 0Use dictword test 1Individual rejection control 1Individual rejection control 1Individual rejection control 0Extend permuter check 0Extend permuter check 0Output text with boxes 0Capture the image from the IPE 0Run interactively? 1According to dict_word 0In multilingual mode use params model of the primary language 0Debug line finding 0Use CJK fixed pitch model 0Allow feature extractors to see the original outline 0Only initialize with the config file. Useful if the instance is not going to be used for OCR but say only for layout analysis. 0Turn on equation detector 1Enable vertical detection 0Force using vertical text page mode 0Preserve multiple interword spaces 1Detect music staff and remove intersecting components 0Script has no xheight, so use a single mode 0Space stats use prechopping? 0Constrain relative values of inter and intra-word gaps for old_to_method. 1Block stats to use fixed pitch rows? 0Force word breaks on punct to break long lines in non-space delimited langs 0Space stats use prechopping? 0Fix suspected bug in old code 1Only stat OBVIOUS spaces 1Only stat OBVIOUS spaces 1Only stat OBVIOUS spaces 1Only stat OBVIOUS spaces 1Use row alone when inadequate cert spaces 0Better guess 0Pass ANY flip to context? 1Don't restrict kn->sp fuzzy limit to tables 0Don't remove noise blobs 0Display unsorted blobs 0Display unsorted blobs 1Reject noise-like words 1Reject noise-like rows 0Debug row garbage detector Class str to debug learning A filename of user-provided words. A suffix of user-provided words located in tessdata. A filename of user-provided patterns. A suffix of user-provided patterns located in tessdata. Output file for ambiguities found in the dictionary Word for which stopper debug information should be printed to stdout Blacklist of chars not to recognize Whitelist of chars to recognize List of chars to override tessedit_char_blacklist .expExposure 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 前置標點符號).,;:?!1st Trailing punctuation 2nd Trailing punctuationPage separator (default is form feed control character) 0.2Character Normalization Range ... 1.5Veto ratio between classifier ratings 5.5Veto difference between classifier certainties 0.125Good Match (0-1) 0Great Match (0-1) 0.02Perfect Match (0-1) 0.15Bad Match Pad (0-1) 0.1New template margin (0-1) 12Avg. noise blob length 0.015Maximum angle delta for prototype clustering 0Penalty to apply when a non-alnum is vertically out of its expected textline position 1.5Rating scaling factor 20Certainty scaling factor 0.00390625Scale factor for features not used 2.5Prune poor adapted results this much worse than best result -1Threshold at which classify_adapted_pruning_factor starts -3Exclude fragments that do not look like whole characters from training and adaption 0.3Max large speckle size 10Penalty to add to worst rating for noise 0.125Score penalty (0.1 = 10%) added if there are subscripts or superscripts in a word, but it is otherwise OK. 0.25Score penalty (0.1 = 10%) added if an xheight is inconsistent. 1Score multiplier for word matches which have good case and are frequent in the given language (lower is better). 1.1Score multiplier for word matches that have good case (lower is better). 1.3125Default score multiplier for word matches, which may have case issues (lower is better). 1.25Score multiplier for glyph fragment segmentations which do not match a dictionary word (lower is better). -2.25Worst certainty for words that can be inserted into the document dictionary -2.25Good blob limit 2最大字元寬高比
Tesseract配置變數 Default 含義
classify_num_cp_levels3類剪裁程式的層級數量
textord_debug_tabfind0除錯標籤查找
textord_debug_bugs0啟用關於標籤查找中的錯誤的輸出
textord_testregion_left-1除錯報告矩形的左邊緣
textord_testregion_top-1除錯報告矩形的上邊緣
textord_testregion_right2147483647除錯矩形的右邊緣
textord_testregion_bottom2147483647除錯矩形的底部邊緣
textord_tabfind_show_partitions0顯示分區邊界,若>1則等待
devanagari_split_debuglevel0分割shiro-rekha過程的除錯級別。
edges_max_children_per_outline10字元輪廓內最大子項數量
edges_max_children_layers5字元輪廓內巢狀子項的最大層數
edges_children_per_grandchild10丟棄輪廓的重點比例
edges_children_count_limit45blob中允許的最大孔洞數
edges_min_nonhole12方框中潛在字元的最少像素
edges_patharea_ratio40Max lensq/area for acceptable child outline
textord_fp_chop_error2允許的切割單元最大彎曲度
textord_tabfind_show_images0Show image blobs
textord_skewsmooth_offset4平滑因子
textord_skewsmooth_offset21平滑因子
textord_test_x-2147483647測試點的坐標
textord_test_y-2147483647測試點的坐標
textord_min_blobs_in_row4在梯度计数前的最小Blob數
textord_spline_minblobs8Min blobs in each spline segment
textord_spline_medianwin6Size of window for spline segmentation
textord_max_blob_overlaps4Max number of blobs a big blob can overlap
textord_min_xheight10Min credible pixel xheight
textord_lms_line_trials12Number of linew fits to do
oldbl_holed_losscount10Max lost before fallback line used
pitsync_linear_version6Use new fast algorithm
pitsync_fake_depth1Max advance fake generation
textord_tabfind_show_strokewidths0Show stroke widths
textord_dotmatrix_gap3Max pixel gap for broken pixed pitch
textord_debug_block0Block to do debug on
textord_pitch_range2Max range test on pitch
textord_words_veto_power5Rows required to outvote a veto
equationdetect_save_bi_image0Save input bi image
equationdetect_save_spt_image0Save special character image
equationdetect_save_seed_image0Save the seed image
equationdetect_save_merged_image0Save the merged image
poly_debug0Debug old poly
poly_wide_objects_better1More accurate approx on wide things
wordrec_display_splits0Display splits
textord_debug_printable0Make debug windows printable
textord_space_size_is_variable0If true, word delimiter spaces are assumed to have variable width, even though characters have fixed pitch.
textord_tabfind_show_initial_partitions0Show partition bounds
textord_tabfind_show_reject_blobs0Show blobs rejected as noise
textord_tabfind_show_columns0Show column bounds
textord_tabfind_show_blocks0Show final block bounds
textord_tabfind_find_tables1run table detection
devanagari_split_debugimage0Whether to create a debug image for split shiro-rekha process.
textord_show_fixed_cuts0Draw fixed pitch cell boundaries
edges_use_new_outline_complexity0Use the new outline complexity module
edges_debug0turn on debugging for this module
edges_children_fix0Remove boxy parents of char-like children
gapmap_debug0Say which blocks have tables
gapmap_use_ends0Use large space at start and end of rows
gapmap_no_isolated_quanta0Ensure gaps not less than 2quanta wide
textord_heavy_nr0Vigorously remove noise
textord_show_initial_rows0Display row accumulation
textord_show_parallel_rows0Display page correlated rows
textord_show_expanded_rows0Display rows after expanding
textord_show_final_rows0Display rows after final fitting
textord_show_final_blobsDisplay blob bounds after pre-ass
textord_test_landscape0Tests refer to land/port
textord_parallel_baselines1Force parallel baselines
textord_straight_baselines0Force straight baselines
textord_old_baselines1
textord_old_xheight0Use old xheight algorithm
textord_fix_xheight_bug1Use spline baseline
textord_fix_makerow_bug1Prevent multiple baselines
textord_debug_xheights0Test xheight algorithms
textord_biased_skewcalc1Bias skew estimates with line length
textord_interpolating_skew1Interpolate across gaps
textord_new_initial_xheight1Use test xheight mechanism
textord_debug_blob0Print test blob information
textord_really_old_xheight0Use original wiseowl xheight
textord_oldbl_debug0Debug old baseline generation
textord_debug_baselines0Debug baseline generation
textord_oldbl_paradef1Use para default mechanism
textord_oldbl_split_splines1Split stepped splines
textord_oldbl_merge_parts1Merge suspect partitions
oldbl_corrfix1Improve correlation of heights
oldbl_xhfix0Fix bug in modes threshold for xheights
textord_ocropus_mode0Make baselines for ocropus
textord_tabfind_only_strokewidths0Only run stroke widths
textord_tabfind_show_initialtabs0Show tab candidates
textord_tabfind_show_finaltabs0Show tab vectors
textord_show_tables0Show table regions
textord_tablefind_show_mark0Debug table marking steps in detail
textord_tablefind_show_stats0Show page stats used in table finding
textord_tablefind_recognize_tables0Enables the table recognizer for table layout and filtering.
textord_all_prop
textord_debug_pitch_test
textord_disable_pitch_test
textord_fast_pitch_test
textord_debug_pitch_metric
textord_show_row_cuts
textord_show_page_cuts
textord_pitch_cheat
textord_blockndoc_fixed
textord_show_initial_words
textord_show_new_words
textord_show_fixed_words
textord_blocksall_fixed
textord_blocksall_prop
textord_blocksall_testing
textord_test_mode
textord_pitch_rowsimilarity
words_initial_lower
words_initial_upper
words_default_prop_nonspace
words_default_fixed_space
words_default_fixed_limit
textord_words_definite_spread
textord_spacesize_ratiofp
textord_spacesize_ratioprop
textord_fpiqr_ratio
textord_max_pitch_iqr
textord_fp_min_width
textord_underline_offset
ambigs_debug_level
classify_debug_level
classify_norm_method
matcher_debug_level
matcher_debug_flags
classify_learning_debug_level
matcher_permanent_classes_min
matcher_min_examples_for_ prototyping
matcher_sufficient_examples_ for_prototyping
classify_adapt_proto_threshold
classify_adapt_feature_threshold
classify_class_pruner_threshold
classify_class_pruner_multiplier
classify_cp_cutoff_strength
classify_integer_matcher_multiplier
dawg_debug_level
hyphen_debug_level
stopper_smallword_size
stopper_debug_level
tessedit_truncate_wordchoice_log
max_permuter_attempts
repair_unchopped_blobs
chop_debug
chop_split_length
chop_same_distance
chop_min_outline_points
chop_seam_pile_size
chop_inside_angle
chop_min_outline_area
chop_centered_maxwidth
chop_x_y_weight
wordrec_debug_level
wordrec_max_join_chunks
segsearch_debug_level
segsearch_max_pain_points
segsearch_max_futile_classifications20Maximum number of pain point classifications per chunk that did not result in finding a better word choice.
language_model_debug_level
language_model_ngram_order
language_model_viterbi_list_ max_num_prunable
language_model_viterbi_list_max_size
language_model_min_compound_length
wordrec_display_segmentations
tessedit_pageseg_mode
tessedit_ocr_engine_mode
pageseg_devanagari_split_strategy
ocr_devanagari_split_strategy
bidi_debug
applybox_debug
applybox_page
tessedit_bigram_debug
debug_noise_removal
noise_maxperblob
noise_maxperword
debug_x_ht_level
quality_min_initial_alphas_reqd
tessedit_tess_adaption_mode
multilang_debug_level
paragraph_debug_level
tessedit_preserve_min_wd_len
crunch_rating_max
crunch_pot_indicators
crunch_leave_lc_strings
crunch_leave_uc_strings
crunch_long_repetitions
crunch_debug0As it says
fixsp_non_noise_limit
fixsp_done_mode
debug_fix_space_level
x_ht_acceptance_tolerance
x_ht_min_change
superscript_debug
jpg_quality
user_defined_dpi
min_characters_to_try
suspect_level99Suspect marker level
suspect_short_words2Don't suspect dict wds longer than this
tessedit_reject_mode
tessedit_image_border
min_sane_x_ht_pixels
tessedit_page_number
tessedit_parallelize
lstm_choice_mode
lstm_choice_iterations
tosp_debug_level
tosp_enough_space_samples_for_median
tosp_redo_kern_limit
tosp_few_samples
tosp_short_row
tosp_sanity_method
textord_max_noise_size
textord_baseline_debug
textord_noise_sizefraction
textord_noise_translimit
textord_noise_sncount
use_ambigs_for_adaption
prioritize_division
classify_enable_learning
tess_cn_matching
tess_bn_matching
classify_enable_adaptive_matcher
classify_use_pre_adapted_templates
classify_save_adapted_templates
classify_enable_adaptive_debugger
classify_nonlinear_norm
disable_character_fragments1Do not include character fragments in the results of the classifier
classify_debug_character_fragments
matcher_debug_separate_windows
classify_bln_numeric_mode
load_system_dawg
load_freq_dawg
load_unambig_dawg
load_punc_dawg
load_number_dawg
load_bigram_dawg
use_only_first_uft8_step
stopper_no_acceptable_choices
segment_nonalphabetic_script
save_doc_words
merge_fragments_in_matrix
wordrec_enable_assoc
force_word_assoc
chop_enable
chop_vertical_creep
chop_new_seam_pile
assume_fixed_pitch_char_segment
wordrec_skip_no_truth_words
wordrec_debug_blamer
wordrec_run_blamer
save_alt_choices
language_model_ngram_on0Turn on/off the use of character ngram model
language_model_ngram_use_ only_first_uft8_step0Use only the first UTF8 step of the given string when computing log probabilities.
language_model_ngram_space_ delimited_language
language_model_use_sigmoidal_certainty
tessedit_resegment_from_boxes
tessedit_resegment_from_line_boxes
tessedit_train_from_boxes
tessedit_make_boxes_from_boxes
tessedit_train_line_recognizer
tessedit_dump_pageseg_images
tessedit_do_invert
tessedit_ambigs_training
tessedit_adaption_debug
applybox_learn_chars_and_char_frags_mode
applybox_learn_ngrams_mode
tessedit_display_outwords
tessedit_dump_choices
tessedit_timing_debug
tessedit_fix_fuzzy_spaces
tessedit_unrej_any_wd
tessedit_fix_hyphens
tessedit_enable_doc_dict
tessedit_debug_fonts
tessedit_debug_block_rejection
tessedit_enable_bigram_correction
tessedit_enable_dict_correction
enable_noise_removal
tessedit_minimal_rej_pass1
tessedit_test_adaption
test_pt
paragraph_text_based
lstm_use_matrix
tessedit_good_quality_unrej
tessedit_use_reject_spaces
tessedit_preserve_blk_rej_perfect_wds1Only rej partially rejected words in block rejection
tessedit_preserve_row_rej_perfect_wds1Only rej partially rejected words in row rejection
tessedit_dont_blkrej_good_wds0Use word segmentation quality metric
tessedit_dont_rowrej_good_wds0Use word segmentation quality metric
tessedit_row_rej_good_docs1Apply row rejection to good docs
tessedit_reject_bad_qual_wds1Reject all bad quality wds
tessedit_debug_doc_rejection0Page stats
tessedit_debug_quality_metrics0Output data to debug file
bland_unrej0unrej potential with no checks
unlv_tilde_crunching0Mark v.bad words for tilde crunch
hocr_font_info
hocr_char_boxes
crunch_early_merge_tess_fails
crunch_early_convert_bad_unlv_chs
crunch_terrible_garbage
crunch_leave_ok_strings
crunch_accept_ok1Use acceptability in okstring
crunch_leave_accept_strings0Don't pot crunch sensible strings
crunch_include_numerals0Fiddle alpha figures
tessedit_prefer_joined_punct0Reward punctuation joins
tessedit_write_block_separators0Write block separators in output
tessedit_write_rep_codes0Write repetition char code
tessedit_write_unlv0Write .unlv output file
tessedit_create_txt0Write .txt output file
tessedit_create_hocr0Write .html hOCR output file
tessedit_create_alto0Write .xml ALTO file
tessedit_create_lstmbox0Write .box file for LSTM training
tessedit_create_tsv0Write .tsv output file
tessedit_create_wordstrbox0Write WordStr format .box output file
tessedit_create_pdf0Write .pdf output file
textonly_pdf0Create PDF with only one invisible text layer
suspect_constrain_1Il0UNLV keep 1Il chars rejected
tessedit_minimal_rejection0Only reject tess failures
tessedit_zero_rejection0Don't reject ANYTHING
tessedit_word_for_word0Make output have exactly one word per WERD
tessedit_zero_kelvin_rejection0Don't reject ANYTHING AT ALL
tessedit_rejection_debug0Adaption debug
tessedit_flip_0O1Contextual 0O O0 flips
rej_trust_doc_dawg0Use DOC dawg in 11l conf. detector
rej_1Il_use_dict_word
rej_1Il_trust_permuter_type1Don't double check
rej_use_tess_accepted
rej_use_tess_blanks
rej_use_good_perm
rej_use_sensible_wd
rej_alphas_in_number_perm
tessedit_create_boxfile
tessedit_write_images
interactive_display_mode
tessedit_override_permuter
tessedit_use_primary_params_model
textord_tabfind_show_vlines
textord_use_cjk_fp_model
poly_allow_detailed_fx
tessedit_init_config_only
textord_equation_detect
textord_tabfind_vertical_text
textord_tabfind_force_vertical_text
preserve_interword_spaces
pageseg_apply_music_mask
textord_single_height_mode
tosp_old_to_method
tosp_old_to_constrain_sp_kn
tosp_only_use_prop_rows
tosp_force_wordbreak_on_punct
tosp_use_pre_chopping
tosp_old_to_bug_fix
tosp_block_use_cert_spaces
tosp_row_use_cert_spaces
tosp_narrow_blobs_not_cert
tosp_row_use_cert_spaces1
tosp_recovery_isolated_row_stats
tosp_only_small_gaps_for_kern
tosp_all_flips_fuzzy
tosp_fuzzy_limit_all
textord_no_rejects
textord_show_blobs
textord_show_boxes
textord_noise_rejwords
textord_noise_rejrows
textord_noise_debug
classify_learn_debug_str
user_words_file
user_words_suffix
user_patterns_file
user_patterns_suffix
output_ambig_words_file
word_to_debug
tessedit_char_blacklist
tessedit_char_whitelist
tessedit_char_unblacklist
tessedit_write_params_to_fileWrite all parameters to the given file.
applybox_exposure_pattern
chs_leading_punct('`"
chs_trailing_punct1
chs_trailing_punct2)'`"
outlines_odd%|非標準輪廓數量
outlines_2ij!?%":;非標準輪廓數量
numeric_punctuation.,Punct. chs expected WITHIN numbers
unrecognised_char|Output char for unidentified blobs
ok_repeated_ch_non_alphanum_wds-?*=Allow NN to unrej
conflict_set_I_l_1Il1 []Il1 conflict set
file_type.tifFilename extension
tessedit_load_sublangsList of languages to load with this one
page_separator
classify_char_norm_range
classify_max_rating_ratio
classify_max_certainty_margin
matcher_good_threshold
matcher_reliable_adaptive_result
matcher_perfect_threshold
matcher_bad_match_pad
matcher_rating_margin
matcher_avg_noise_size
matcher_clustering_max_angle_delta
classify_misfit_junk_penalty
rating_scale
certainty_scale
tessedit_class_miss_scale
classify_adapted_pruning_factor
classify_adapted_pruning_threshold
classify_character_fragments_ garbage_certainty_threshold
speckle_large_max_size
speckle_rating_penalty
xheight_penalty_subscripts
xheight_penalty_inconsistent
segment_penalty_dict_frequent_word
segment_penalty_dict_case_ok
segment_penalty_dict_case_bad
segment_penalty_dict_nonword
certainty_scale20Certainty scaling factor
stopper_nondict_certainty_base-2.5Certainty threshold for non-dict words
stopper_phase2_certainty_rejection_offset1Reject certainty offset
stopper_certainty_per_char-0.5Certainty to add for each dict char above small word size.
stopper_allowable_character_badness3Max certaintly variation allowed in a word (in sigma)
doc_dict_pending_threshold0Worst certainty for using pending dictionary
doc_dict_certainty_threshold
tessedit_certainty_threshold
chop_split_dist_knob0.5Split length adjustment
chop_overlap_knob0.9Split overlap adjustment
chop_center_knob0.15Split center adjustment
chop_sharpness_knob0.06Split sharpness adjustment
chop_width_change_knob5Width change adjustment
chop_ok_split100OK split limit
chop_good_split50Good split limit
segsearch_max_char_wh_ratio

為了獲得最佳效果,建議在應用OCR之前使用IronOCR的圖像預處理濾鏡。 這些濾鏡可以顯著提高準確性,特別是在處理低質量掃描或像表格這樣的複雜文件時。

常見問題

如何在 C# 中配置 IronTesseract 進行 OCR?

要配置 IronTesseract,請建立 IronTesseract 實例,並設置如 Language 和 Configuration 等屬性。您可以指定 OCR 語言(從 125 個支援語言中),啟用條碼閱讀,配置可搜尋 PDF 輸出,及設置字元白名單。例如:var tesseract = new IronOcr.IronTesseract { Language = IronOcr.OcrLanguage.English, Configuration = new IronOcr.TesseractConfiguration { ReadBarCodes = false, RenderSearchablePdf = true } };

IronTesseract 支援哪些輸入格式?

IronTesseract 接受透過 OcrInput 類的各種輸入格式。您可以處理影像(PNG、JPG等)、PDF 檔案及掃描文件。OcrInput 類提供靈活的方法來載入這些不同格式,讓您可以輕鬆地對幾乎任何包含文字的文件進行 OCR。

我可以使用 IronTesseract 同時讀取條碼和文字嗎?

可以,IronTesseract 包括進階的條碼閱讀功能。您可以在 TesseractConfiguration 中設定 ReadBarCodes = true 來啟用條碼檢測。這允許您在單次 OCR 操作中從同一文件提取文字及條碼資料。

如何從掃描文件建立可搜索的 PDF?

IronTesseract 可以通過在 TesseractConfiguration 中設定 RenderSearchablePdf = true 將掃描文件和圖像轉換成可搜尋的 PDF。這樣做會建立文字可選取和搜尋的 PDF 檔案,同時保留原始文件的外觀。

IronTesseract 支援哪幾種語言的 OCR?

IronTesseract 支援 125 種國際語言的文字識別。您可以設置 IronTesseract 實例的 Language 屬性來指定語言,如 IronOcr.OcrLanguage.English、西班牙語、中文、阿拉伯語等。

我可以限制 OCR 識別哪些字元嗎?

可以,IronTesseract 允許透過 TesseractConfiguration 中的 WhiteListCharacters 屬性進行字元白名單和黑名單設定。當您知道預期的字元集時,此功能有助於提高準確性,例如僅限於識別字母及數字字元。

如何同時對多個文件進行 OCR?

IronTesseract 支援多執行緒功能以進行批量處理。您可以利用平行處理同時對多個文件進行 OCR,從而大幅提升處理大量圖像或 PDF 檔案的效能。

IronOCR 使用哪一個版本的 Tesseract?

IronOCR 使用一個自定義且經過優化的 Tesseract 5 版本,稱為 Iron Tesseract。這個增強引擎在提高準確度及性能的同時,仍保持與 .NET 應用程式的相容性。

IronOCR如何提高資料精確性?

IronOCR通過其先進的識別算法和影像校正功能提高資料精確性,確保文字提取過程既可靠又精確。

IronOCR有免費試用版嗎?

有的,Iron Software提供IronOCR的免費試用版,允許使用者在做出購買決定前測試其功能和能力。

Curtis Chau
技術作家

Curtis Chau擁有Carleton大學的電腦科學學士學位,專精於前端開發,擁有Node.js、TypeScript、JavaScript和React的專業知識。Curtis熱衷於建立直觀且美觀的使用者介面,喜愛使用現代框架並建立結構良好、視覺吸引力的手冊。

除了開發,Curtis對物聯網(IoT)有濃厚的興趣,探索創新的方法來整合硬體和軟體。在空閒時間,他喜歡玩遊戲和建立Discord機器人,結合他對技術的熱愛與創造力。

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Jeff Fritz
Jeffrey T. Fritz
首席計劃經理 - .NET社區團隊
Jeff還是.NET和Visual Studio團隊的首席計劃經理。他是.NET Conf虛擬會議系列的執行製作人,並主持每週兩次的開發者直播節目'Fritz and Friends',在節目中討論技術並與觀眾一起撰寫程式碼。Jeff撰寫工作坊、演講和內容計劃,為微軟開發者的最大活動如Microsoft Build、Microsoft Ignite、.NET Conf和Microsoft MVP Summit提供內容支援。
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