CS cropping tool

[darb]

Ive found when i use the cropping tool in PS CS and set to 12 x 4 inches, that it actually increases the res to 3600 x whatever ... is there a way to use the cropping tool to force the crop to a certain aspect ratio, but not actually upsize or downsize the image?

ie, if youi just use the normal selection tool, then choose image crop, it simply crops off the pixels, but the cropping tool actually resizes the image ... id like to force an AR when cropping, but not upsize it. Likewise when just cropping a normal 3:2 image.

[Alex]

Darb,

In a top bar there is a box to be checked "preserve aspect ratio" or something to that effect.
Alex

[joolz]

Hi Darb,
I think what is happening is that you have a number entered in the resolution box in the crop control panel (at the top). This resizes the image to that particular pixel density when you crop. It's useful when you want an exact replica or specific resolution, but obviously not in your case.
Leave it blank & see if it helps

Joolz

[darb]

if i leave those fields blank however, the crop tool becomes non-forced in regards to aspect ratio, if you get what i mean?

[joolz]

Fill in the width & height as 12 & 4 (note: clicking on the arrows in between quickly switches the values - landscape to portrait or vice versa). Leave the resolution box (next to pixels/inch) empty. This should constrain your crop tool selection to the correct aspect ratio (ie. 3:1) but not resize the selection resolution.

Hope that helps

Joolz

[Deano]

Darb,

I think what Joolz is saying is set the width and hieght but leave resolution blank. This is what I do when I'm cropping to a specific dimension. You can then use image resize to set the resolution for printing later if required.

Cheers
Dean

Edit: I was too slow - opened CS to check what I was saying.

[Hlop]

Darb,

You have to use "Select" tool instead of "Crop" tool. When using "Select" tool , in toolbar you can choose Style -> Fixed Aspect Ratio, select what you want, and then menu "Image -> Crop". In this case picture will be cropped witout resampling, like you cropping postcard with scissors

[darb]

thanks y'all will try it shortly. hlop, sounds exactly like what im after.

[darb]

Darb,

You have to use "Select" tool instead of "Crop" tool. When using "Select" tool , in toolbar you can choose Style -> Fixed Aspect Ratio, select what you want, and then menu "Image -> Crop". In this case picture will be cropped witout resampling, like you cropping postcard with scissors

perfect. Exactly what i was after

the crop tool, even if the 'pixels per inch" is left out, still resamples the image rather than just "trimming" so to speak.

[Hlop]

Glad to help!

The only disadvantage of this method is that Select Tool isn't too felxibe and convenient as Crop Tool but if you find out how to use "add", "substract" etc. options in toolbar you'll be fine

[Deano]

the crop tool, even if the 'pixels per inch" is left out, still resamples the image rather than just "trimming" so to speak.

I disagree Darb.

Just did the following test;
- created 10cm x 10cm blank image at 300ppi = 1181 pixels square
- crop using 5 x 5 with resolution blank
= 5cm x 5cm image at 299.72ppi (rounding) = 590 pixels square.

OK, I should have used inches for easier maths but the result is the same

To me this is not a resample.

Either way if you have found a solution which works for you then cool.

Cheers
Dean

[joolz]

Yes, I agree with Deano,
It shouldn't resize your pic with the crop tool if you leave resolution blank. (check with image> image size - ppi will remain the same)
However, one of the great things about PS is there are usually several ways to do any one thing just in case you don't like one particular way.

Joolz

[Hlop]

Sorry guys, have to disagree with that.

Experiment (just done it):
Source: NEF, 3008x2000, 300 ppi. So, it's 25.47 x 16.93 cm

Cropping with a crop tool, say to 20 x 10 cm, leaving resolution field blank.
Result: 269.494 ppi

Cropping with a select tool, using fixed size
Result: 300ppi

Cropping with a select tool, using fixed aspect ratio
Result: 300 ppi, but different size in cm

But it doesn't resample image

[Deano]

Now that is weirder than a very weird thing with weird bits on it...

I did your experiment - 3008 x 2000 NEF @300 ppi. Crop tool set 20cm x 10cm, resolution blank. Crop to 20 x 10 and got 299.974 ppi (rounding again).

Interesting...

Cheers
Dean

[Deano]

Perhaps I am stupider than a stupid thing hit with the stupid stick and dipped in stupid but the way I understand this is...

Setting a width/height in the crop tool means that the resulting crop will print at the specified size. Without setting a resolution this will not resample and the resulting resolution will be #pixels/# inches. If you set a dimension within the existing size of the image and then crop to exactly that dimension then the PPI will not change. Any smaller or larger will restate the PPI in terms of the number of pixels spread over the requested output size.

For example an image 10" x 10" at 300ppi will be 3000 x 3000 pixels.
Set crop dimensions to 4" x 6" (blank resolution) and then actually select 4" x 6" (1200 x 1800 pixels) you will get 300ppi. If however you leave the dimensions the same and select 2" x 3" worth (600 x 900 pixels) then the ppi will be 150 as the pixels are spread over a wider area when output to 4" x 6".

In either case no resampling has occured.

Makes sense to me

Cheers
Dean

[Hlop]

Deano, you're right but when you're using select tool with "Fixed aspect ratio" option it will not resample image in ANY case. You can select few pixels and crop the rest. That's my point.

[darb]

hlop : that tool is great, except you cant fine tune your selection, you have to deselect and redo it ... so the crop tool is better in that regard

with regard to the whole resample, resize, wahtever points ... im more talking about simply 'trimming' off the edges using a forced aspect ratio

Ie, i want to force and maintain the 3:2 ratio, and use the crop tool to do it.

the only way i know at the moment is to type in say "12 x 8 inch" (to put ina relevant aspect ratio) ... i leave the resolution blank, and make my crop ... the WxH went to 2269 x 1513 which appears to have "trimmed" as i wanted ... but it has modified the resolution to 189 pixels per inch ... which i DIDNT want to modify.

I dont want to modify the image to a certain print size, i want to leave as much info there as possible. I dont want to enlarge or reduce, i just wanna lob the edges off, if i trim HEAPS off, then end up with a H X W thats fine.

Using HLOPS tool (and turning on the "fixed aspect ratio" and just put a 3 and a 2 (ratio integers, not actual pixel or inch measurements) ) , choosing the same crop, i got the same WxH (2269 x 1513), but the resolution stayed at 300PixelsPerInch

im not sure i mathematically understand whats going on here ... just not sure why its reduced PPI to 189 when i use a crop tool. If i specify 300PPI and 12 x 8 inch (as a way to instruct the tool what aspect ratio i want.) ... then i end up a 3600 x 2400 version of my crop !

[joolz]

Sorry guys, my Sony.
The crop tool does recalculate the ppi.
However, it does not resample the image.
What happens is that it recalculates the image ppi as if it were the requested width/height.
The number of pixels is exactly the same, however, the calculated ppi is changed.
This is rectifiable by using image>image size and changing the resolution back to 300. (Do not check resample image)
This will correct values back in line with the original image.
This does not alter the actual image in any way. It merely is a calculated value from the number of pixels and the intended print size.
Hopefully that will clear up the confusion.

Joolz

[darb]

ok so it doesnt actually muff the image, just calculates it different?

cant say i understand the maths of it, but its late and im tired, so meh!