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Beep6581 / RawTherapee

A powerful cross-platform raw photo processing program
https://rawtherapee.com
GNU General Public License v3.0
2.9k stars 323 forks source link

Allow resizing to physical dimensions #4894

Open Beep6581 opened 6 years ago

Beep6581 commented 6 years ago

Every once in a while someone asks how to resize an image in RawTherapee to a physical dimension in centimeters or inches based on pixels per inch (PPI). I tried to solve that problem.

Beep6581 commented 6 years ago

Duplicates:

Beep6581 commented 6 years ago

Branch hihowdoisaveaphotoat300dpi implements a working solution.

screenshot_20181026_022533

The scaling is based on pixels, so dimensions in centimeters and inches are not stored, just calculated when needed. Only the PPI value is stored.

I know very little about C++ and would appreciate help with several things:

Heads up @TooWaBoo and other theme designers: RawTherapee still hard-codes most widget spacing values instead of leaving that up to the CSS the GTK3 way. The Resize tool now uses two grids without hard-coded spacing, and instead leaves the spacing up to CSS. All grids which require spacing to be set by CSS are assigned a class grid-spacing, see here: https://github.com/Beep6581/RawTherapee/blob/hihowdoisaveaphotoat300dpi/rtdata/themes/RawTherapee-GTK3-20_.css#L1040

Beep6581 commented 6 years ago

Notes to self, review language keys when merging: TP_RESIZE_ALLOW_UPSCALING (capitalization), delete all TP_RESIZE_W and TP_RESIZE_H

Thanatomanic commented 6 years ago

Just to say, love your branch name. What I would prefer from a GUI point of view is to try and reduce the crowding. What I think I have seen elsewhere is a toggle (or tabs) that shows you either the pixel values, or the DPI + physical sizes, not both at the same time.

Hombre57 commented 6 years ago

@Beep6581 I'll have a look at the pedited problem tomorrow. Great that you added this feature :+1:

Hombre57 commented 6 years ago

@Beep6581 Before looking at the pedited problem, the Crop tool already has a PPI spin button for information purpose only, with informational label. I think those should be moved to the Resize tool and updated when the Crop tool is changed.

Instead of adding 2 supplementary spin button not handled in the ProcParams, the unit combobox should simply tell the unit of the actual width and height values, with px / mm / in entries (px as default, for compatibility).

If unit is set to px, the PPI is the consequence of the new size in pixel, in which case the PPI spin button should be made unsensitive (if not in batchmode).

If the unit is set to mm or in, the PPI should be made sensitive (if not in batchmode) and the hint label updated (if not in batchmode).

Beep6581 commented 6 years ago

@Hombre57 I see no need for the PPI stuff being in the crop tool, but that's one of several separate issues with the crop tool, let's not mix those here.

I will consider the other suggestions.

Beep6581 commented 6 years ago

@Hombre57 I like your idea and haven't thought of drawbacks - I'll implement it.

Hombre57 commented 6 years ago

@Beep6581 My comment was i bite incorrect. PPI should always be sensitive and put as is in the output file, but :

In batch mode, you should just hide the informative label. Whatever the unit is set to in each of the selected files, the user is responsible for the coherency of the values set in width and height.

Thanatomanic commented 4 years ago

For reference: https://discuss.pixls.us/t/note-to-the-dev-guys-about-72-ppi-output/18570 There is still a wish for this to work.