Re. your questions - I don't know :-( For my videos I took 640x480 FLV screencasts (from ShowMeDo.com - pretty high quality videos with hardly any artefacts) and I ran tesseract 2 on the colour screengrabs without rescaling.
What resolution are you capturing at? If the fonts are small you might want to manually try to sharpen the image, in case anti-aliasing/smoothing is blending adjacent characters into one another? You could visually confirm if this looks to be the case. Maybe you could upload a sample screengrab and explain what it gets right and which errors it gets (maybe by drawing on the image)? i. On 1 September 2010 03:26, Quan Nguyen <[email protected]> wrote: > Hi Ian, > > I'm implementing a feature in my program to enable OCR of screenshots. > The results have been generally better after the captured images were > rescaled from 96 DPI to 300 DPI. I was wondering if other simple > manipulations could be done programmatically to the images to produce > even better results. > > The types of the screenshots are either 32bppArgb or 24bppRgb. Would > changing to grayscale or stripping the Alpha help? > > Quan > > On Aug 31, 12:17 pm, "Ian Ozsvald (A.I. Cookbook)" > <[email protected]> wrote: >> Hi Quan. >> >> I've used tesseract to OCR frames from 640x480 screencast videos, >> generally it worked >> fine:http://ianozsvald.com/2010/05/17/extracting-keyword-text-from-screenc... >> >> What problems are you seeing when you try tesseract? >> >> Ian. >> >> On 30 August 2010 23:46, Quan Nguyen <[email protected]> wrote: >> >> > I understand the resolutions of screenshots are typically inadequate >> > for OCR, but besides rescaling to a higher resolution, say, 300 DPI, >> > what other preprocessing operations may be needed on the images to >> > yield optimal OCR results? >> >> > Thanks. >> >> > -- >> > You received this message because you are subscribed to the Google Groups >> > "tesseract-ocr" group. >> > To post to this group, send email to [email protected]. >> > To unsubscribe from this group, send email to >> > [email protected]. >> > For more options, visit this group >> > athttp://groups.google.com/group/tesseract-ocr?hl=en. >> >> -- >> Ian Ozsvald (A.I. researcher, screencaster) >> [email protected] >> >> http://IanOzsvald.comhttp://MorConsulting.com/http://blog.AICookbook.com/http://TheScreencastingHandbook.comhttp://FivePoundApp.com/http://twitter.com/IanOzsvald > > -- > You received this message because you are subscribed to the Google Groups > "tesseract-ocr" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/tesseract-ocr?hl=en. > > -- Ian Ozsvald (A.I. researcher, screencaster) [email protected] http://IanOzsvald.com http://MorConsulting.com/ http://blog.AICookbook.com/ http://TheScreencastingHandbook.com http://FivePoundApp.com/ http://twitter.com/IanOzsvald -- You received this message because you are subscribed to the Google Groups "tesseract-ocr" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/tesseract-ocr?hl=en.
