How to check if an image contains an element I am searchig for

[Arak Rachael]

On Wednesday, 16 June 2021 at 23:44:02 UTC+2, Chris Angelico wrote:
> On Thu, Jun 17, 2021 at 7:35 AM Dan Stromberg <drsa... at gmail.com> wrote:
> > 
> > On Wed, Jun 16, 2021 at 2:04 PM Barry <ba... at barrys-emacs.org> wrote: 
> > 
> > > >>> On Thu, Jun 17, 2021 at 6:06 AM Arak Rachael <arakelt... at gmail.com> 
> > > wrote: 
> > > >>> 
> > > >>> Hi guys, 
> > > >>> 
> > > >>> I have an image from google maps to say and I need to check if it has 
> > > road markings, in order to do that, I believe I need to change the effects 
> > > on the image so the markings and road can be white or something and the 
> > > things I don't need like cars, trees and so on to be black. 
> > > >>> 
> > > >>> images should contain only road surface and/or road markings (lines, 
> > > zebras, stripes. 
> > > >>> 
> > > >>> Can anyone help me on this, I already have the crop code, I just need 
> > > to check if the cropped part contains what I need. 
> > > >> How well can you define the things you're looking for? 
> > > >> 
> > > >> https://xkcd.com/1425/ 
> > > >> 
> > > >> ChrisA 
> > > > Hi Chris, 
> > > > 
> > > > what do you mean? 
> > >
> > > He means that image processing is a hard problem that requires expertise 
> > > to solve. 
> > > 
> > > >
> > > > Here is the image, I need to separate the road and markings from the 
> > > rest and divide the image into squares of 100x100 pixels, for each square I 
> > > need to check if it contains a road and markings: 
> > >
> > > Can you define road in terms of an algorithm that looks at the pixels? 
> > > 
> > 
> > I think that XKCD may be a little out of date.
> It's not out of date. The task still requires a lot of effort - it's 
> just that the effort is now "preparing a suitable corpus" rather than 
> "figuring out how on earth to do this". Even with all the tools at our 
> disposal, there's still a stark (and often surprising) distinction 
> between the easy and the hard. 
> 
> For instance, calculating square roots is pretty hard to do by hand, 
> but computers don't have any trouble with that. But "what's that song 
> about blah blah blah" is incredibly difficult, and if you try to write 
> your own tool to do that (rather than doing what most people would do, 
> and type something into a search engine!), you'll find that it's far 
> easier to just give the job to a human.
> > You could probably train a Deep Learning model to do this, if you have 
> > enough prelabeled data with enough variation.
> That is, in fact, the exact difficulty.
> > And of course dividing a picture up into 100x100 squares is pretty easy if 
> > you convert to ppm. Perhaps Pillow can do this too.
> Sure, but that's the trivially easy part. And probably not even all 
> that helpful in the scheme of things. 
> 
> ChrisA
I understand your concerns. Actually I am doing image processing of satellite pictures for smart cars. I have been given the option to use InfranView and do it manually or create a Python script.