Please see https://github.com/tesseract-ocr/tesseract/wiki/4.0-with-LSTM
For info about neural nets used by tesseract On Fri 27 Apr, 2018, 7:48 PM Janpieter Sollie, <[email protected]> wrote: > I had a quick thought about what you could offload to opencl. I will need > some help from you people (I am a C programmer, not C++, at least not > experienced) to do the host code, but this algorithm is perfectly > optimizeable in openCL. > the way I'd do it: > > prerequirements: > - you can define 65k offsets (x,y) in whose you want the openCL engine to > look for dots (x,y), the optimal position and closest neighbour can be > reported in the first part. > - you can make a RAW image of both the image and the characters. size of > the letters doesn't matter, but they must be trimmed properly > > 1. you give me a matrix of 256*256 offsets(short, short) to analyze, with > a max of 64 dots (char, char) (I assume these are neurons) to analyze in > each offset. > so, this gives you a start memory usage of 2⁸ * 2⁸ *4 + 64*2 = 256k + > 128 bytes > each dot MUST contain a black pixel. > then we add the image, this is a charimage of max (to be discussed with > you guys), I assume a 4096*4096 pixel image would be fine, especially when > a character can contain a 4x4 matrix defining a 0/1 (black/white) value. > 2. Then I follow these steps in the openCL engine: > - we analyze the neurons > - draw a cirle around them of x black points. (this circle can be 0, > in which case the neuron is white), for which the circle is completely > black > - when we encounter one or more white points, a direction of the > points is calculated. if there's no whitespace at the other side, the > neuron offset is moved for x/2 in the opposite direction and analyze neuron > is restarted for x/2. else, quit the 'analyze neuron' part. This can be > done in local memory, in which case it will cost you 256*2=512 bytes of > local ram to determine the optimal neuron position. Most graphic cards have > a limit of 32k ram, so this is no problem :-) > - determine the closest dot next to this one: > for each dot != this one, draw a line of black points, if no line can > be found, jump to next dot. > watch distance. If it's smaller than the previous neuron && this dot > id hasn't a link pointing from the destination to this one, save dot id. > so, at the end: > - each neuron of each offset is optimally centered in a return matrix > of 256*256*64*2 = 2²³ = 8M of memory > - each neuron has a unique id to its closest neighbour, to which it's > guaranteed to be attached. an id of -1 means no id could be found. > 256*256*64 = 4M of memory > > 3. we focus on neuron list -> character mapping. this is a separate > kernel. A "probability" factor is involved here, but I will think about it > further. I suggest to use a list of 64 character images at once, otherwise > you need lots of memory :-) > - define the top, left and right neuron. create a zoom factor for the > image. calculate the aspect ratio. The probability is > 1-diff(aspect_ratio1, aspect_ratio2) > - analyze each link in the font character. total probability *= > (found_link_length / total_link_length) > - report the probability. > On the PC: the character with the highest probability is the character you > 're looking for. Be aware that you need to compare the possibilities of > the different offsets if they overlap. > > if the tesseract project can use this, please let me know > > 2018-04-27 9:36 GMT+00:00 Zdenko Podobny <[email protected]>: > >> Only documentation we have is code itself ;-) But you can start with >> searching for opencl issue in tesseract issue tracker on github... >> >> Zdenko >> >> >> pi 27. 4. 2018 o 10:56 Janpieter Sollie <[email protected]> >> napísal(a): >> >>> I'd be glad to help. using tesseract 4, I am able to perform a 90% >>> accuracy on OpenCL. I do not have any experience with neural networks (i'm >>> just a high-school (no college educated IT-support guy with some knowledge >>> about OpenCL), so can you recommend me some documentation to understand the >>> engine of tesseract 4? >>> >>> 2018-04-27 10:50 GMT+02:00 Zdenko Podobny <[email protected]>: >>> >>>> If you have experience your help will be warmly welcomed. >>>> OpenCL is not maintained and it is on good way to be removed if >>>> maintainer/contributor will not be found. >>>> Anyway it is not used extensively, so there is a place for improvement, >>>> >>>> Zdenko >>>> >>>> >>>> pi 27. 4. 2018 o 10:21 Janpieter Sollie <[email protected]> >>>> napísal(a): >>>> >>>>> Hello everyone, >>>>> >>>>> I have a question about the openCL selection procedure of tesseract: >>>>> >>>>> my output: >>>>> >>>>> [DS] Profile read from file (tesseract_opencl_profile_devices.dat). >>>>> [DS] Device[1] 1:Fiji score is 0.202927 >>>>> [DS] Device[2] 1:Ellesmere score is 1.468799 >>>>> [DS] Device[3] 1:Ellesmere score is 1.468799 >>>>> [DS] Device[4] 1:Bonaire score is 1.533776 >>>>> [DS] Device[5] 1:Tonga score is 0.184236 >>>>> [DS] Device[6] 0:(null) score is 1.123015 >>>>> [DS] Selected Device[5]: "Tonga" (OpenCL) >>>>> >>>>> Ugh, this is weird .. why does tesseract take my Tonga instead of my >>>>> fiji device? can I force it to use the fiji? >>>>> I understand the ellesmere have lower access times (they 're behind a >>>>> pcie switch), but fiji and tonga are both directly connected via a pcie >>>>> 2.0 >>>>> X16 bus. Do we need a better tesseract selection procedure? >>>>> If so, I'm quite skilled at opencl, I'd be glad to help! >>>>> >>>>> kind regards, >>>>> >>>>> Janpieter >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "tesseract-ocr" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> To post to this group, send email to [email protected]. >>>>> Visit this group at https://groups.google.com/group/tesseract-ocr. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/tesseract-ocr/4568b2b8-532d-457c-920b-60407e7b278e%40googlegroups.com >>>>> <https://groups.google.com/d/msgid/tesseract-ocr/4568b2b8-532d-457c-920b-60407e7b278e%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> -- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "tesseract-ocr" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/tesseract-ocr/uNRDFTavDfc/unsubscribe >>>> . >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> To post to this group, send email to [email protected]. >>>> Visit this group at https://groups.google.com/group/tesseract-ocr. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/tesseract-ocr/CAJbzG8wHCUBmAs3Q8%3D%2BzBPODuuDPS2g%3DZ-6Gve%3DLWpzVWwvTkw%40mail.gmail.com >>>> <https://groups.google.com/d/msgid/tesseract-ocr/CAJbzG8wHCUBmAs3Q8%3D%2BzBPODuuDPS2g%3DZ-6Gve%3DLWpzVWwvTkw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "tesseract-ocr" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/tesseract-ocr. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/tesseract-ocr/CAJEYFEaZNSWsV-hL-9DYWJahUR-8_3Wi%2BO5XwRkwFPWZHZgSOA%40mail.gmail.com >>> <https://groups.google.com/d/msgid/tesseract-ocr/CAJEYFEaZNSWsV-hL-9DYWJahUR-8_3Wi%2BO5XwRkwFPWZHZgSOA%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "tesseract-ocr" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/tesseract-ocr/uNRDFTavDfc/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/tesseract-ocr. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/tesseract-ocr/CAJbzG8yBJ8UcP-Oy-fkJ_zcszj2OUDag3zJdEd_qZbQpD0F6Yg%40mail.gmail.com >> <https://groups.google.com/d/msgid/tesseract-ocr/CAJbzG8yBJ8UcP-Oy-fkJ_zcszj2OUDag3zJdEd_qZbQpD0F6Yg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "tesseract-ocr" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/tesseract-ocr. > To view this discussion on the web visit > https://groups.google.com/d/msgid/tesseract-ocr/CAJEYFEYVKhsUxP280ZXwMZoS262d8scEbYrCF9QE-0BseUdg6w%40mail.gmail.com > <https://groups.google.com/d/msgid/tesseract-ocr/CAJEYFEYVKhsUxP280ZXwMZoS262d8scEbYrCF9QE-0BseUdg6w%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "tesseract-ocr" group. 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