Exporting high resolution pictures and local manipulation tool

(Gianni Saccardo) #1

Hi all,
I am Gianni and I am a newbie and I am facing a little problem that I can not solve by myself:
After having worked on a raw file in RT 5.4 (both Linux and Mac), I need to output as a 100% size at 300ppi Tif.
I have managed to do the steps described in rawpedia to have the result I need but… I am still having a perfect TIF file 4 times sized but at 72 ppi. There is any way to have my file at 300ppi out of RT?!?!?

I take the occasion to ask if there is also a tool (maybe a brush) to work on my photo locally?
Thanks a lot for your help.!!!

(Morgan Hardwood) #2

Hi @Gianni_Saccardo

PPI means nothing, ignore it.
Learn more about what it is here:

If you disable the Resize tool, you will get a full-sized, 100% image.

Local editing is not possible in RT, but RT can export the image directly to GIMP.

(Gianni Saccardo) #3

Thanks Morgan,
for the tool… I’ve argued that there is any other way than external editor.

Speaking about resolution, please take a look at the 2 screenshot

As You may see the result is a 72ppi image. I need it to be 300.
I can’t find a way to do it in RT.

Thanks for your support.

(Mica) #4

In Photoshop, just change the 72 to 300.

(Morgan Hardwood) #5

@Gianni_Saccardo what about the image do you expect to change by setting it to 300PPI?

(Gianni Saccardo) #6

Too basic to be useful…

(Gianni Saccardo) #7

Easy, size and resolution.
That means no lost of time resizing elsewhere :wink:

(Alberto) #8

Hi @Gianni_Saccardo,

without knowing the output size in inches (or in some saner unit like cm :-), saying that you need “300PPI” doesn’t mean anything… what is the output size you want?

(Gianni Saccardo) #9

I’m developing some images for a book on Blurb, they ask for a certain size and a certain resolution, having to resize all in some external editors sounds tricky and need a passage more, this means time.
After all RT is a great piece of software, sharpening and noise reduction modules are first class product.
Alsa color correction is quite easy and powerfull, local contrast and retinex works perfectly.
But not having the possibility to export in a certain size on a certain resolution… make no sense for me!
(A brush for local correction would be the perfect gift)

(Gianni Saccardo) #10

As you can see from the screenshot, I was expecting a 34x51 cm /300ppi image.
At the end I had a 72x200cm /72ppi…

(Alberto) #11

Which means you need an (approx) 6000x4000 image. When printed at 300ppi resolution, it will result in 6000/300 x 4000/300 inches, i.e. 20x13.33 inches, i.e. 50.8x33.8 cm…

Or perhaps you are asking that the intended PPI is part of the image metadata?

(Alberto) #12

If this is the case, this should do (assuming your image is actually 6000x4000):

$ exiftool -XResolution=20 -YResolution=13.3 -ResolutionUnit=in FILENAME.tif

(Morgan Hardwood) #13

So what you’re really asking for is not setting some metadata tag, but changing the pixel resolution of an image to fit a given physical size at a given pixel density. That is not easily doable yet. Keep an eye out on issue #54.

(Alberto) #14

There must be something I’m missing… :thinking:
sure it would be convenient to have this in RT, but if you know the PPI, determining the required size in pixels is not that hard, isn’t it?

(Morgan Hardwood) #15

@agriggio it’s not easily doable in RT. You’d either need to whip out the calculator.exe, or abuse the crop tool’s PPI calculation. Neither is user-friendly.

(Gianni Saccardo) #16

Ok, found how to do it.
CROP panelworks only exporting a jpg, tif comes out at 72, strange…

(Gianni Saccardo) #17

It could work… tif, would be better, but it works.
@Morgan_Hardwood Morgan, are you the engineer behind RT?

(Morgan Hardwood) #18

@Gianni_Saccardo JPEGs come out with XResolution=YResolution=300. TIFFs don’t have those tags set at all. The PPI setting in the Resize tool does not get saved as a tag.

@agriggio and I are from the RawTherapee project, there are others.

(Morgan Hardwood) #19

I’ll see what I can do about #54 once I’m done with a few other issues.

(Gianni Saccardo) #20

Thanks a lot for your help.
I think that RT worth gold, so developping it is a great (and hard job).
@agriggio I think you are italian, right?
Tell me how may I contribute (not only economically) to enhance this wonderful project.
I see a great potential in it!