They are just basic 96-DPI window screen prints, such as those generated by Print Screen key. I've implemented the function by merely rescaling the images to 300 DPI, but just wonder if any more improvement is possible with only minor preprocessing. Any tips would have been appreciated; but otherwise, I'm OK with the improved results from the rescaling.
Thanks for your response. On Sep 1, 3:56 am, "Ian Ozsvald (A.I. Cookbook)" <[email protected]> wrote: > 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.... > > > -- > > 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.
