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Groups > comp.lang.python > #100539
| From | BartC <bc@freeuk.com> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Why my image is in bad quality ? |
| Date | 2015-12-16 23:20 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <n4srh1$kv$1@dont-email.me> (permalink) |
| References | (5 earlier) <mailman.16.1450284070.30845.python-list@python.org> <0f56d024-0193-4d28-97ac-7d71c806f379@googlegroups.com> <f21c3910-11d4-4d22-88f8-55940141bbca@googlegroups.com> <n4slc7$6gp$1@dont-email.me> <2c67af3c-6954-4398-81c8-0459025bc5c7@googlegroups.com> |
On 16/12/2015 21:53, fsn761304@gmail.com wrote: > On Thursday, December 17, 2015 at 1:36:55 AM UTC+4, BartC wrote: >> You need to test step by step to see at what point it goes wrong. You're >> scaling by 20 (which is a massive amount); what happens when scaling by >> 1? And anti-alias is turned off? (Which might let you see by how many >> pixels each successive line is out and could give a clue.) >> >> It does seem as though something is going amiss with recognising the >> image dimensions, or you've inadvertently applied a 'shear' or 'slant' >> transformation. (Maybe you can apply a reverse transform to fix it!) >> >> -- >> Bartc > > Original size: 150x30 > Original image the same, but without skew (usual upright letters). > When scaling by less than 20 recognition quality is bad (in another code, which doesn't use buffer, screenshot, but loads image from a directory). > Antialias makes no difference. > Shear, slant - ok, show me how. I've played with a 150x30 reduced image. The best I can do is apply a shift that makes the letters slant the other way, but at only half the angle. Trying to get them upright makes them wobbly. (I did this with some code - not Python - that read each pixel and stored it at a shifted position. But this is because I'm not familiar with manipulation programs.) So whatever's gone wrong might be more complex. You should forget about recognition quality, and find out what it is that's applying the skew (another name for shear or slant). That seems to be being applied before the scaling, which is giving the 'steps' in the sloping edges. -- Bartc
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Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-16 06:04 -0800
Re: Why my image is in bad quality ? Denis McMahon <denismfmcmahon@gmail.com> - 2015-12-16 14:15 +0000
Re: Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-16 06:21 -0800
Re: Why my image is in bad quality ? Chris Angelico <rosuav@gmail.com> - 2015-12-17 01:33 +1100
Re: Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-16 08:33 -0800
Re: Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-16 08:35 -0800
Re: Why my image is in bad quality ? Chris Angelico <rosuav@gmail.com> - 2015-12-17 03:41 +1100
Re: Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-16 09:01 -0800
Re: Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-16 09:17 -0800
Re: Why my image is in bad quality ? BartC <bc@freeuk.com> - 2015-12-16 21:36 +0000
Re: Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-16 13:53 -0800
Re: Why my image is in bad quality ? BartC <bc@freeuk.com> - 2015-12-16 23:20 +0000
Re: Why my image is in bad quality ? Nobody <nobody@nowhere.invalid> - 2015-12-17 01:27 +0000
Re: Why my image is in bad quality ? fsn761304@gmail.com - 2015-12-17 03:31 -0800
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