Division problem

[caperucitaroja]

Hi @ll!

[davegee]

if you want to be really accurate you need a 4:3 resolution which is divisible by three.

1200*900 fits the bill.

drag guides in to 400 & 800 and down to 300 & 600.

crop to the guides at max magnification for accuracy.

re assemble in a 1200*900 frame and use zoom on the frame to fit to 1024*768 in pte.

dg

[Lin Evans]

You didn't say "how" you want to split the image. You can do it horizontally, vertically, or with three across and three down rectangles. You can do it as David suggests with Photoshop or your favorite editor, or you can do it the "easy" way with PhotoScape. I would suggest trying PhotoScape, it's free, powerful, and easy to use. Splitting is only one of many features. See it here:

http://download.cnet.com/PhotoScape/3000-2192_4-10703122.html

Best regards,

Lin

Hi @ll!

I have a question:

I would like to split an image of 1024 x 768 in nine equal rectangles.

Somebody know any way to do it. (Photoshop?)

Little Red Riding Hood

[davegee]

like venetian blinds?in thar case use 1200*900 and bring the guides down at 100 px intervals?

dg

[David Porter]

if you want to be really accurate you need a 4:3 resolution which is divisible by three.

1200*900 fits the bill.

drag guides in to 400 & 800 and down to 300 & 600.

crop to the guides at max magnification for accuracy.

re assemble in a 1200*900 frame and use zoom on the frame to fit to 1024*768 in pte.

dg

Insead of cropping to the guides why not use the rectangular marque tool set at 300 x 200 and this will then snap to the guides.

[davegee]

Mick,

I went through that a long time ago - it's just not accurate enough.

If you want pixel perfection for the OP's purposes you need to make sure that your guides are perfectly placed (Max Magnification). Then you need to make sure that your Crop or Rectangular Marquee is perfectly aligned to the guides.

Try it?

DG

[vilara]

There is in Photoshop slice tool (in crop tool) that allows to cut an image into parts

[David Porter]

Mick,

I went through that a long time ago - it's just not accurate enough.

If you want pixel perfection for the OP's purposes you need to make sure that your guides are perfectly placed (Max Magnification). Then you need to make sure that your Crop or Rectangular Marquee is perfectly aligned to the guides.

Try it?

DG

Hi Dave,

I would not have suggested my method had I not tried it (see my Leeds Castle or Bodium opening and closing shots somewhere here). To clarify - select your photo and size in our case to 900 x 600 px,type the figures you want for the guides in View/New Guide,300, 600 and 900 one way and 200 and 400 the other way. The guides are then perfectly placed. Type the figures for the rectangles (in the case we were assuming 300 x 200 pixels)into Fixed Size on the Rectangular Marque Tool. Click into a rectangle on the grid and with "Snap" ticked move marque towards the grid lines and it will snap into place. Ctrl J to make this a layer. Do the same for all the other rectangles then hide the background layer. You will then have a perfect copy of the original and you can magnify this as much as you want and move one of the layers out of position and back again and you will not see the join.

Academic, I know as LRRH is using Photoscape.

[fh1805]

Little Red Riding Hood,

Your problem is caused because all the nine images are slightly different sizes. To achieve perfect alignment it is essential that all the images are EXACTLY the same size. As DaveGee said, you must begin with an image that is EXACTLY divisible by 3 on both axes. A size of 1024 x 768 is not exactly divisible by 3 on its long axis. Having said that, it is possible that you might be able to work around the problem by turning off "Edge anti-aliasing" for each of the nine segments in the O&A Properties tab.

regards,

Peter

[fh1805]

Hi LRRH,

Bosque4_001 and bosque4_002 are still the original sized versions. You have not replaced these with 1200x900 versions.

Peter

[davegee]

Mick,

EXCELLENT tip re: Precise positioning of guides.

Now all I have to do is remember!

I have been dragging guides in whilst in maximum magnification to ensure precise guides. After that the "snap" takes care of things.

Thanks,

DG

[davegee]

Bosque4_001 and 002 are 341x256 as Peter noticed?

Presumably these are 4:3 crops from a 1024x768 image? This is impossible on the long side as you would need a decimal part of a pixels - cannot be done.

I rebuilt your project at 1200x900 on my 1920x1200 monitor and can make it work albeit that the pan figures have decimal parts of a percentage point - Peter uses Excel for this and would be able to tell you exactly what you require - 66.666% (I think).

Using this figure with a 100% view (in O&A) on my monitor there are no lines. There are also no lines in Preview.

You have probably noticed that the lines are vertical and that there are no horizontal line problems?

DG

[fh1805]

Dave,

Actually, bosque4_002 is 342x256. It seems as though Photoscape realised it couldn't divide 1024 exactly by 3 and so cut the two outer images at 341 and the middle one at 342 on each row.

Peter

[davegee]

Peter,

This goes back to JPD's original objections to the abolition of Original Mode.

DG

[Barry Beckham]

Can I ask why the need to create your artwork at 1024*768, I am sure your not using a monitor of that resolution. What is your monitor resolution?

[Lin Evans]

Hi Barry,

Why would you assume that she isn't using 1024x768? That's the resolution I use. I have monitors which support up to 1920x1080 but the print is too difficult to see at the higher resolutions and none of my cameras shoot at 16:9 aspect ratio.

I don't have a problem working at 1024x768 and have no problems with image quality.

Best regards,

Lin

Can I ask why the need to create your artwork at 1024*768, I am sure your not using a monitor of that resolution. What is your monitor resolution?

[Barry Beckham]

Lin

It think it was a reasonably assumption to make based on my gut feeling that most people are using higher resolutions. That seems to be backed up by one or two surveys I have seen that quote 80+% of users are using a resolutions above 1024*768. I think its also reasonable to assume that if the same survey was carried out among photographers the figure would be at least 80% and probably higher.

I don't mean to insult anyones choice, just thought the task that was asked may have been a little easier at a higher resolution.

[davegee]

I suspect that if the OP had a 1080 high monitor this thread would not exist. The OP would then be working at 1440x1080.

I'll do the maths for you.

1440 and 1080 are divisible by BOTH 4 and 3.

100% of desktop computer packages sold in High Street computer shops in the UK come with 1080 high monitors.

I belong to a CC with 100 members. I don't know of any digital workers who works at anything below 1080 high.

Some of those members lecture with 1024x768 projectors (the FRPS member has a 1920x1080 projectors the same as the club's own). There is absolutely no need for any of them to work with projects smaller than 1440x1080.

I have a 1920x1200 monitor and have had for a few years. A search of this forum would probably pinpoint the date I bought it accurately. I made up my mind a couple of years ago that when the time comes to replace it I will opt for 1920x1080 (my TV is 1920x1080 - that's a clue). All of my projects end up on my TV as MPEG4 so I work to the TV's 1080 high. I have been using 1620x1080 (3:2) quite a lot (my camera is 3:2 - that's a clue). However, my 3:2 shows are superimposed on a 1920x1080 background to preserve the 16:9 AR.

I suspect that the 1200 high monitor is doomed and that I will not be able to replace like for like anyway. There are plans to up the TV resolutions so that will probably, at some time in the future, bring about another resolution revolution. I'm trying to keep up - it's the only way.

DG

[Barry Beckham]

caperucitaroja

My apologies, I seemed to have asked the wrong question about screen resolution, which I now regret asking. Please forget I ever asked.

[davegee]

Davegee, I think you've gone through the branches in this forest. :D

Is that related with my simple question?

Yes, it relates to the use of a more suitable resolution for what you are/were trying to acheive, but I'll drop it.

DG