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Making multiple selections (being a div?)


Paul

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What topic is your new thread on/about?
 
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um.... okay it's pretty specific so here goes.I work for a company that makes vents and vent canopies for windows, and i basically need to cut out an image of a vent, including all the little square holes - BUT what i want to do is do it quickly, and make sure that each line is at the same angle.

now i'm ASSUMING then, that i'd be asking about selections, and adding to selections, or something, but I'm not quite sure if that's the quickest way to go around it...
should i post a photo ?


thanks in advance,

Jenny
 

Tom Mann

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To be honest, this sounds more like a photography problem (ie, minimize distortion when you take the photo), and thereby you'll only need to do minimal touch-up work with Photoshop, after the fact.

BTW, yes, definitely post a photo or two. It will give us a much better idea of what you are dealing with.

Once we see exactly what type of technical problem you have, one of us will almost certainly move the thread to the best forum, and probably even change the title to be more descriptive, so don't worry if you see that happen.

Cheers,

Tom M
 
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hiya Tom,

No, I think judging by your response you may have misunderstood me, but that's probably entirely my fault - and it's also worth noting that even though I do sincerely believe I am asking a photoshop question, I also have no doubt that yes, my photography could also always improve!

Let me show you a file, I think that could help.


View attachment forum help exampel.psdView attachment forum help exampel.psd

ok let me explain. What you can see is a photograph of a vent canopy in picture A. I have already done various effects (curves, saturation etc for my own demands that I know we require for various reasons that are too boring to explain)


Then i cut the image out using polygonal lasso tool, because this image might go in a catalogue, where it overlaps something, so it is useful to have it pre-cut out.

HOWEVER, the issue i'm facing is as follows ; if you can spy the red dot in picture a, that area is actually a hole, showing table top underneath, so i need to cut that out too. the trouble is, every single area with an orange dot in it is exactly the same.

I can sit and do it one by one like in the example picture b, but the problems are as follows;

- INCREDIBLY TIME CONSUMING AND I HAVE LOTS OF DIFFERENT VENTS TO DO

- and the main issue (that is probably quite picky but I don't like it) is that there is no way to gaurantee the angle of the horizontal(ish) lines of each selection i make will match up with one another. Now, from a distance, i doubt it would matter, but the overall effect any closer up than "from a distance" is wonky, un parallel lines.

So i think what my question is, is as follows - is there a way to make a selection point, in one fell swoop, from the green dot a, and the green dot b, and the same between green dot c, and green dot d, and then add extra selections for the vertical (ish) selections?


does that make any sense at all?!

thanks in advance for your patience,
Jenny

p.s. sorry i may have accidentally uploaded two versions of the same file, please check as my question refers to whichever one also includes green dots, not just orange and red :)
 

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  • forum help exampel.psd
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IamSam

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Hello and welcome to PSG.

Unfortunately, this may be a learning experience for you. This is a ultimately a photography problem. The product should have been shot on a completely contrasting background color than the color of the product itself. By doing so, there would be several techniques available to you that would have allowed you the option of making the selection of the small slots in one "fail swoop". As it is, the color of the tabletop is too similar to the color of the product making the selection process almost impossible.

Myself and others will try to see if there is an easier way, in the meantime, you may be stuck selecting them individually as you have been doing.

My only advice is that you learn to use the Pen Tool instead of the Polygonal Lasso Tool and work on a layer mask. By using a layer mask, mistakes can easily be corrected.
 

IamSam

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By using the Pen Tool, you can make exact selections (including the curve at the bottom)........
Screen Shot 2015-07-23 at 8.16.21 AM.png

Screen Shot 2015-07-23 at 8.16.32 AM.png

Once you have the selection, select the layer mask and fill the selection with black.

Screen Shot 2015-07-23 at 8.17.19 AM.png

Screen Shot 2015-07-23 at 8.17.29 AM.png
 
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hiya,

can you talk me through how you would do it if this vent was shot on a black background, as you suggest?

so there is definitely no way, with the shots that I do have, to make a selection, and then basically edit the selection ? so make a selection of the entire grated area, and then add the vertical selections afterwards?

I vaguely know pen tool, but not layer masks - i'll look in to this with a touch of google!

thanks IamSam :) also, just for your reference, it's one fell swoop, not fail swoop as you put. It never seems to be said in the states, I certainly never heard anyone say it when I lived there, but it comes from an old English word "felon" which meant fierce.

so do it quickly, in one fierce strike, if that makes sense.

thanks for help!
Jenny
 

IamSam

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can you talk me through how you would do it if this vent was shot on a black background, as you suggest?
Sure, notice here that I have used SELECT > COLOR RANGE to select the orange.....
Screen Shot 2015-07-23 at 8.25.06 AM.png

Then I added and selected the layer mask and filled the selections with black. All gone "One FELL swoop".
Screen Shot 2015-07-23 at 8.30.02 AM.png

so there is definitely no way, with the shots that I do have, to make a selection, and then basically edit the selection ? so make a selection of the entire grated area, and then add the vertical selections afterwards?
Working on it.

just for your reference, it's one fell swoop, not fail swoop as you put. It never seems to be said in the states, I certainly never heard anyone say it when I lived there, but it comes from an old English word "felon" which meant fierce.
Thanks, I knew this. My spell check changed it and I did not catch it.
 
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hi

great thankyou :D . I hope I didn't offend you, I just quite like etymology - so they obviously DO say it in Texas? this looks really helpful, I will try it at work tomorrow, thank you so much! x
 

IamSam

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No offense.

I lived near Ipswich for 4 years. (RAF Woodbridge/Bentwaters)

edit: spell check again!
 
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IamSam

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A yank..from Texas. My father was USAF and we were stationed at the now closed bases in the UK.
 

MrToM

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Just to add to the excellent advice already given...

You have to appreciate that a digital image is just a bunch of coloured squares, or pixels....that's it.

Us humans can 'see' recognizable patterns of pixels and interpret them as 'objects' that we see in the real world.

In order for that to be done by a 'computer' is extremely difficult....simply distinguishing between an image of a Cat and an image of a Dog is today still an incredibly difficult task to do and more often than not a 'computer' will fail and do no better than a 50:50 guess.

To us though cats and dogs are like chalk and cheese....no problem.

Putting that into context where PS is concerned it too just sees a whole bunch of coloured pixels....it's US that makes the decision on what the pattern of those pixels represent.....in your case a 'vent'.

There isn't, therefore, a way to isolate these 'objects' merely by calculation alone, which is what PS has to use....two identically coloured pixels could [to us] be completely different objects in the image.....like in your case...the 'vent' is very similar to its background, as IamSam has pointed out.

To us it's obvious, but when you go by the numbers there is no 'obvious' difference between any of the pixels at all....they are all the same with only their colour changing.

Therefore in order to differentiate between 'objects' PS needs something numerical to work with.....a difference in luminosity, contrast, colour, sharpness etc etc.....it cannot simply use 'what the image looks like' and it cannot do it by itself....we have to 'tell' PS what method to use.....yeah, PS is actually pretty dumb when you think about it....it's also colour blind too but that's a different story.

The suggestion of a much more contrasting background would have given us the contrast needed for PS to distinguish between a 'dark' pixel and a 'light' one making selecting those 'dark' ones much easier...as it stands the bits we want are almost identical to those we don't......its the "white cat in snow storm" situation.

I'm sure you were fully aware of all this but when people start talking about 'objects' and how to get PS to select them they often don't understand that PS just sees a whole bunch of coloured pixels...well, greyscale pixels actually but whatever.

Using a 'Levels' adjustment layer and a 'Threshold' adj layer I came up with a mask that with a little more 'painting' gives this result...

vents_MT_01.jpg

...but your image is pretty small so its not at its best.

Regards.
MrToM.
 
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hi all,

Mr Tom, that's a great way to explain it - and it's very easy to think as you say, and then start "tutting" because photoshop simply isn't "LOOKING PROPERLY!" but yes you are right, it's not a human, so it can't think like one and view things like one.

I'm back in today and have taken some photos of the white vent on a blue background (i thought we had something black but alas, no)

i'll probably fair better with something like this? IMG_5830.JPG
 

MrToM

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...i'll probably fair better with something like this?...

Better? Yes. :thumbsup:
Best? No. :frown:

Its a big improvement for certain and I managed to get a reasonable result from it...

vent_MT_01.png

...but can you see how your image could be a little different to make it much easier?

Ideally, knowing you will have several of these to do, its makes sense to make things as easy as possible for yourself when in PS...and thus get better results.

You've got the idea of 'contrast' now which makes selection much much easier but....it could be better...here are just some things I would try to do:

1. Keep the lighting constant. Note how your image is lighter on the left.
Whilst not the end of the world selecting a 'narrow' range of a colour is better than a 'wide' range.

2. Avoid shadows.
Again, not the end of the world but avoiding shadows means we don't have to deal with them....and less is more....right? This goes for shadows on the background and also on the object itself...from say a 'flash'.

Lifting the object away from the background not only reduces shadows but also reduces any 'colour cast' created by the background......not too bad in your image but none at all is obviously best.

3. Ratio of object to image.
I did a rough 'outline' of the 'vent' and counted how many pixels it contained.....roughly 218573px.

I then calculated the total amount of pixels in the image...3264 x 2448 = 7990272px

Now, 218573 / 7990272 = 0.027...or just 2.7% !!!

Making the 'object' occupy as much of the image as possible is an absolute must when doing this kind of work.....especially as you have total control over it.

As it stands, 97% of that image we are not interested in.....and that's a lot.

Fill that viewfinder with 'vent' Jennifer......the bigger the better! :thumbsup:

These are just what I'd do.....the most difficult there is getting the object away from the background to remove shadows and colour casting but it really depends on how accurate you need to be...the image you supplied is fine although having the object fill more tha 2.7% of the image would be a huge advantage......and this is really easy as you're the one taking the photo's.

There are many varied ways to 'cut out' those pixels now that there is something to work on.....I didn't use a conventional method but they should all yield pretty much the same results.

We're getting there though......its pretty simple to do and if you could take a photo which is more 'vent' than background I'll go through the method I used.....unless someone beats me to it. :biglaff:

Regards.
MrToM.
 
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hi Mr Tom,

Yes it all makes sense, i've been using a bit of blue tac for anything that won't stand up on it's own, maybe i could raise things up a little with some of that.

In regards to filling the picture, I'm sadly taking these photos with an ihpone - our camera is very out of date, and i read somewhere that you shouldn't zoom in with an iphone camera because it's a lesser quality image? I can't remember the reason why.

I think for now this will be good enough, ultimately the vents are only going to be small, it's not a sexy product in the slightest, it's really simply because we have about 4 proper photographs even though we sell bloomin hundreds of products - we are ALWAYS scrabbling around, and re-using, and I just figured we could do with a few more options.


HOWEVER all your advice is definitely stuff I will take on board for some of my OWN projects :) which is part of the joy of my job, I get to learn it (with help from you peeps) for vents and canopies and mechanical ventilation units but I can then utilise the skills for whatever I like afterwards.

The only problem with the lighting, I am having to compromise between where i put the lamp and where I put the tripod - if i try and light it bang from the front to get even lighting, my tripod will be miles away and the vent will be even less than 2.7% of the photo!

what is your opinion?

Can i just say how grateful I am to all of you for helping, thank you so much :D xx
 

MrToM

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No worries...

The image is fine.....we can work with it.

The points I raised are really just for reference when we go into PS.....hopefully you will be able to see 'why' a particular method / technique is used based on the properties of the image....like gradients and contrast.

If you can give me a short while I'll get something together to explain how I got to the image above.

Regards.
MrToM.
 
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hi Tom,

yes there's no rush, I'm just grateful for any help. Also I'm here on my own so my work pace is my own. and Besides everyone else here seems filled with inertia so no matter how much or little I do in a day I am still more proactive than anyone else!
(not to sound big headed, just, energetic and the youngest person at this work place)

hows this picture? I have taken it with your advice on board (using the more oldschool camera)
IMG_3118.JPG

i'm aware it's quite a bit darker - I have another lamp which I was going to use, one at the front, one at the back, but it's trapped in the meeting room with a director!

thanks everyone!
 

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