OCR - 使用tesseract 3.0和imagemagick 6.6.5从图像中获取文本 [英] OCR - Getting text from image using tesseract 3.0 and imagemagick 6.6.5
问题描述
我正在尝试构建一个允许我在图像中搜索文本的shell脚本。根据文本，脚本将尽力从图像中获取文本。我想要你的输入，因为这个脚本似乎适用于大多数图像，但不是那些文本字体颜色类似于文本周围较小环境的图像。
I am trying to build a shell script that allows me to search for text in an image. Based on the text, the script will try its best to get the text from the image. I wanted your input on this as this script seems to work with most images, but not those images where the text font color is similar to smaller-surroundings around the text.
# !/bin/bash
#
# imt-ocr.sh is image magick tessearc OCR tool that is used for finding out text in image
#
# Arguments:
# 1 -- image filename (with path)
# 2 -- text to search in image (default to '')
# 3 -- occurence of text (default to 1)
# Usage:
# imt-ocr.sh [image_filename] [text_to_search] [occurence]
#
image=$1
txt=$2
occurence=$3 # Default to 1
if [ "$occurence" == "" ]
then
occurence=1
fi
get_major_color ()
# Returns the major color of an image with its hex value
# Parameter: Image filename (with path)
# Return format: Returns a string "hex_val_of_color major_color_name"
{
convert $1 -format %c histogram:info: > x.txt
cat x.txt | awk '{print $1}' > x1.txt
h=$(sort -n x1.txt | tail -1);
color_info=$(cat x.txt | grep "$h" | cut -d '#' -f2)
rm -rf x.txt x1.txt
echo "$color_info"
}
invert_color()
# Inverts the color hex value
# Parameter: Hex value to be inverted
# Return format: Returns in hex
{
input_color_hex=$1 # Input color's hex value
white_color_hex=FFFFFF # White color's hex vlaue
inv_color_hex=`echo $(printf '%06X\n' $((0x$white_color_hex - 0x$input_color_hex)))`
echo $inv_color_hex
}
start_scale=100
end_scale=300
increment_scale=100
tmp_img=dst.tif
attempt=1
for ((scale=$start_scale, attempt=$attempt; scale <= $end_scale ; scale=scale+$increment_scale, attempt++))
do
echo "IMT-OCR-LOG: Scaling image to $scale% in attempt #$attempt"
convert $image -type Grayscale -scale $scale% $tmp_img
tesseract $tmp_img OUT
found_oc=$(grep -o "$txt" OUT.txt | wc -l)
echo "IMT-OCR-LOG: Found $found_oc occurence(s) of text '$txt' in attempt #$attempt"
if [ $occurence -le $found_oc ] && [ $found_oc -ne 0 ]
then
echo "IMT-OCR-LOG: Printing out the last text found on image"
echo "IMT-OCR-LOG: ======================================================"
cat OUT.txt
echo "IMT-OCR-LOG: ======================================================"
rm -rf $tmp_img OUT.txt
exit 1
else
echo "IMT-OCR-LOG: Getting major color of image in attempt #$attempt"
color_info=`get_major_color $image`
true_color=$(echo $color_info | awk '{print $2}')
true_val=$(echo $color_info | awk '{print $1}')
echo "IMT-OCR-LOG: Major color of image is '$true_color' with hex value of $true_val in attempt #$attempt"
# Blur the image
echo "IMT-OCR-LOG: Bluring image in attempt #$attempt"
convert $tmp_img -blur 1x65535 $tmp_img
# Flip the color
inverted_val=`invert_color $true_val`
echo "IMT-OCR-LOG: Inverting the major color of image from 0x$true_val to 0x$inverted_val in attempt #$attempt"
convert $tmp_img -fill \#$inverted_val -opaque \#$true_val $tmp_img
# Sharpen the image
echo "IMT-OCR-LOG: Sharpening image in attempt #$attempt"
convert $tmp_img -sharpen 1x65535 $tmp_img
# Find text
tesseract $tmp_img OUT
found_oc=$(grep -o "$txt" OUT.txt | wc -l)
echo "IMT-OCR-LOG: Found $found_oc occurence(s) of text '$txt' in attempt #$attempt"
if [ "$found_oc" != "0" ]
then
if [ $occurence -le $found_oc ]
then
echo "IMT-OCR-LOG: Printing out the last text found on image"
echo "IMT-OCR-LOG: ======================================================"
cat OUT.txt
echo "IMT-OCR-LOG: ======================================================"
rm -rf $tmp_img OUT.txt
exit 1
fi
fi
fi
rm -rf OUT.txt
done
rm -rf $tmp_img
以下是一个有问题的示例示例，
image（test.jpeg） http：/ /www.igoipad.com/wp-content/uploads/2012/07/03-Word-Collage-iPad.jpeg
Here is a sample example with problem, image (test.jpeg) http://www.igoipad.com/wp-content/uploads/2012/07/03-Word-Collage-iPad.jpeg
[admin@ba-callgen image-magick-tesseract-processing]$ sh imt-ocr.sh test.jpeg Common
IMT-OCR-LOG: Scaling image to 100% in attempt #1
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Common' in attempt #1
IMT-OCR-LOG: Getting major color of image in attempt #1
IMT-OCR-LOG: Major color of image is 'grey96' with hex value of F5F5F5 in attempt #1
IMT-OCR-LOG: Bluring image in attempt #1
IMT-OCR-LOG: Inverting the major color of image from 0xF5F5F5 to 0x0A0A0A in attempt #1
IMT-OCR-LOG: Sharpening image in attempt #1
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Common' in attempt #1
IMT-OCR-LOG: Scaling image to 200% in attempt #2
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 1 occurence(s) of text 'Common' in attempt #2
IMT-OCR-LOG: Printing out the last text found on image
IMT-OCR-LOG: ======================================================
Settings M...
Text
Common words
Exclude numbers
word case
Theme & Layuul
Color theme
Fnnl
Word layout
Clrien lalion
7301
Lrmclsc ape
\u2018OTC
Ergl sw v.-ords >
li( `
I):Jntc1'\:1r\qa )
Landon Spring >
Hough Trad >
H3'fJ|1d :-Ialf >
H L
IMT-OCR-LOG: ======================================================
[admin@ba-callgen image-magick-tesseract-processing]$
[admin@ba-callgen image-magick-tesseract-processing]$
[admin@ba-callgen image-magick-tesseract-processing]$
[admin@ba-callgen image-magick-tesseract-processing]$
[admin@ba-callgen image-magick-tesseract-processing]$
[admin@ba-callgen image-magick-tesseract-processing]$
[admin@ba-callgen image-magick-tesseract-processing]$ sh imt-ocr.sh test.jpeg Portrait
IMT-OCR-LOG: Scaling image to 100% in attempt #1
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Portrait' in attempt #1
IMT-OCR-LOG: Getting major color of image in attempt #1
IMT-OCR-LOG: Major color of image is 'grey96' with hex value of F5F5F5 in attempt #1
IMT-OCR-LOG: Bluring image in attempt #1
IMT-OCR-LOG: Inverting the major color of image from 0xF5F5F5 to 0x0A0A0A in attempt #1
IMT-OCR-LOG: Sharpening image in attempt #1
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Portrait' in attempt #1
IMT-OCR-LOG: Scaling image to 200% in attempt #2
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Portrait' in attempt #2
IMT-OCR-LOG: Getting major color of image in attempt #2
IMT-OCR-LOG: Major color of image is 'grey96' with hex value of F5F5F5 in attempt #2
IMT-OCR-LOG: Bluring image in attempt #2
IMT-OCR-LOG: Inverting the major color of image from 0xF5F5F5 to 0x0A0A0A in attempt #2
IMT-OCR-LOG: Sharpening image in attempt #2
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Portrait' in attempt #2
IMT-OCR-LOG: Scaling image to 300% in attempt #3
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Portrait' in attempt #3
IMT-OCR-LOG: Getting major color of image in attempt #3
IMT-OCR-LOG: Major color of image is 'grey96' with hex value of F5F5F5 in attempt #3
IMT-OCR-LOG: Bluring image in attempt #3
IMT-OCR-LOG: Inverting the major color of image from 0xF5F5F5 to 0x0A0A0A in attempt #3
IMT-OCR-LOG: Sharpening image in attempt #3
Tesseract Open Source OCR Engine with Leptonica
IMT-OCR-LOG: Found 0 occurence(s) of text 'Portrait' in attempt #3
[admin@ba-callgen image-magick-tesseract-processing]$
如你所见，我可以找到文本常见，但不是肖像。原因是肖像的字体颜色。任何改进此脚本的帮助......
As you can see I can find text "common", but not "Portrait". The reason is because of the font color of the Portrait. Any help to improve this script...
我使用的是Centos 5.
I am using Centos 5.
推荐答案
在操作输入图像时，不要人为限制自己只评估一种或两种方法。您似乎现在只使用 -blur 和 -scale 。
Do not artificially limit yourself to just evaluate one or two methods when you manipulate your input image. You seem to only use -blur and -scale right now.
您还应该考虑使用以下操作：
You should also consider to use the following operations:
-
-contrast -
-despeckle -
-edge -
-negate -
-normalize -
-posterize -
-type灰度 -
-monochrome -
-gamma -
-antialias / + antialias
-contrast-despeckle-edge-negate-normalize-posterize-type grayscale-monochrome-gamma-antialias / +antialias
输入图片：
请参阅此命令生成的内容：
See for example what this command produces:
convert 03-Word-Collage-iPad.jpeg \
-scale 1000% \
-blur 1x65535 -blur 1x65535 -blur 1x65535 \
-contrast \
-normalize \
-despeckle -despeckle \
-type grayscale \
-sharpen 1 \
-posterize 3 \
-negate \
-gamma 100 \
-compress zip \
a.tif
输出图片： < br>
（对不起，当将TIFF上传到这个网站时，它会自动转换为PNG。因此，在下载上面看到的图像时，你并没有真正得到我的TIFF - 但你仍然可以看到我真实结果的足够图片。）
Output Image:
(Sorry, when uploading a TIFF to this website it gets auto-converted to PNG. So you don't really get my TIFF when downloading the image you see above -- but you'll nevertheless see a close-enough picture of my real result.)
注1：我使用此ImageMagick版本对此进行了测试：
Note 1: I tested this with this ImageMagick version:
convert -version
Version: ImageMagick 6.7.6-9 2012-05-12 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features:
注2： ImageMagick的旧版本或更新版本的行为可能有所不同，尤其是涉及到 -posterize ！
Note 2: Older or newer versions of ImageMagick may behave differently, especially when it comes to -posterize!
这是Tesseract的OCR a.tif ：
And this is the result of Tesseract's OCR for a.tif:
tesseract a.tif OUT && cat OUT.txt
Tesseract Open Source OCR Engine v3.01 with Leptonica
Page 0
Text
Common words Remove English words >
Exclude numbers
Word case Don't change 1+
Theme & Layout
Color theme London Spring >
Font Rough Trad >
Word layout Half and Half >
Orientation
Landscape
Q
u
-0
"H
I
更新：
我验证了最新版本of ImageMagick 6.7.9-0 （昨天发布）与我在上面显示的命令+截图（用版本 6.7制作）产生的结果不一样.6-9 ）。区别在于：
Update:
I verified that the most recent version of ImageMagick 6.7.9-0 (released yesterday) does not produce the same exact result as I showed with above command + screenshot (made with version 6.7.6-9). Here is the difference:
无论如何，我确定你是否稍微调整了我的命令，玩各种参数，你无论你的ImageMagick版本是什么，都能让它为你工作......
In any case, I'm sure if you tweak my command a bit, playing with various parameters, you'll get it to work for you, whatever your ImageMagick version is...
这篇关于OCR - 使用tesseract 3.0和imagemagick 6.6.5从图像中获取文本的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
![http：/ /www.igoipad.com/wp-content/uploads/2012/07/03-Word-Collage-iPad.jpeg](\"http://www.igoipad.com/wp-content/uploads/2012/07/03-Word-Collage-iPad.jpeg\"){kind=link}