Upsizing / Downsizing Question - Am I missing it?

[JayS]

All,
    I posted this embedded in another topic and thought perhaps it could stand on its own.  During the export function, the only way I can see that you can "resize" in LR is via the Constrain Maximum Size and then supply width and height.  Although I haven't tried it, how would this work in a process where a larger group of photos have been edited, both Landscape and Portrait, and I now wanted the entire group to be downsized by 50% of the original pixel count.  Most all packages I've seen have Percentage as an option.  Am I totally missing something here?  I suppose one could set up various Export files to do 50% Portrait and one for 50% Landscape, etc., but this seems like quite a number of extra steps.  All the RAW Processors I've got, C1, RSP, etc., all allow for a percentage, bypassing the concerns I mentioned.  Thanks in advance.

Jay S.

[tomrock]

Just make both dimensions 50% of the longer measurement. In other words, if your original files are 3500 x 2300, enter 1750 x 1750 in the resize box.

[JayS]

Just make both dimensions 50% of the longer measurement. In other words, if your original files are 3500 x 2300, enter 1750 x 1750 in the resize box.
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Tom,
    Then proportionally, the image wouldn't be correct and length to width ratio is lost.  That is why in packages such as allow you to specify a percentage and constrain the typical 1.5 proportion.  Even though in Adobe Raw, the save function is limited to that constraint with a drop down selection, other packages at least allow you to not have to treat Portrait and Landscape separately, or calculate what you sizes you need if you want say 40% of the original size.  I truly hope that this isn't the only place to be able to resize an image, or that the answer is to convert to JPEG and have to resize through Photoshop or another package where you also have choices for up and down sampling methods, such as bicubic, etc.

Jay S.

[Richard Marcellus]

As Tom mentioned, if you set the width and height to the same value with Constrain Maximum Size selected, then the longest dimension of your file (whether it is portrait or landscape) will be set at that size. The shorter side will be appropriately shorter depending on your aspect ratio. Your image will not be turned into a square.

Richard

[JayS]

As Tom mentioned, if you set the width and height to the same value with Constrain Maximum Size selected, then the longest dimension of your file (whether it is portrait or landscape) will be set at that size. The shorter side will be appropriately shorter depending on your aspect ratio. Your image will not be turned into a square.

Richard
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Richard and Tom,
     O.K., got it understand the logic now.. Not an absolutely intuitive way of getting there and still would love to see a percentage option a well, but works and thanks.  Now the next question.  What methods are being used for up and down sampling vs. some of what is there in CS2, and even QImage for that matter.  Thanks again.

Jay S.

[tomrock]

Now the next question.  What methods are being used for up and down sampling vs. some of what is there in CS2, and even QImage for that matter.  Thanks again.

Jay S.
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I really don't know what method LR uses but you could try this: Open an image in PS and resize it using the various bicubics PS offers. Save the files.

Then export the same image from LR at the same size as above and see if it matches any of your files from above.

You could use the compare feature in LR to look at them side by side.

Then come back and tell me what you find. I'm curious, but I'm lazy. :-)

Tom

[julian_love]

On a related note, how do I upsize photos on export from Lightroom? My picture library wants 50MB TIFF files, and the output of my 1DsII are 48MB files. Currently I have to export as TIFF and then run a batch action in PS.


I can't see any option for upsizing in the export dialogue from LR...and would prefer to do it all in one step if possible.

Julian

[tomrock]

Julian, Take a look at the Image Settings section of the Export dialog. You can put in whatever size you need, up to a point.

[JayS]

On a related note, how do I upsize photos on export from Lightroom? My picture library wants 50MB TIFF files, and the output of my 1DsII are 48MB files. Currently I have to export as TIFF and then run a batch action in PS.
I can't see any option for upsizing in the export dialogue from LR...and would prefer to do it all in one step if possible.

Julian
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Julian,
    I believe I read the max is 10,000 by 10,000.  If you need to go beyond that, or perhaps for even more choices with better results, you may want to also look at QImage.  I know it is mostly known for printing (and is excellent), but has a wealth of different methods for resizing.

Jay S.

[julian_love]

Thanks tomrock - I hadn't realised I could put in image dimensions that were larger than the original file in the Export dialogue. The word "constrain" before "image size" made me think I could only put in a smaller value. It pays to experiment!

Julian