Maybe this is a good idea, maybe not. 

I take pictures of different objects on the same background, with the same light source and intensity all the time. I use Gimp to edit those pictures. The camera will vary exposure, aperture, ISO, etc... depending on the object which will change the apparent color of the background. 

If I know the actual color of the background (say 90.7, 85.8, 85.8 in a RBG format) how would I apply a filter to color correct the entire image based on the change needed between the current background color and the known background value?

I am looking to try and get the most consistent/accurate colors for the objects. If this is not a good option, please let me know if you think there is a better way to do this. Bear in mind that I am really trying to make up for the camera and getting a better/different camera is not a viabile option at this time.

Out of nowhere  Gimp switched to single window mode with fixed panels. So I unchecked the single window box and it reverted to a blank page. When I go to Windows>Dockable Dialogs and click on the Layers Panel, for example, it opens the panel but it jumps to full page spread out in a horizontal format.

How can I restore my set-up to a normal page with movable panels for Layers, Tools, etc.?

I am doing astrophotography and I added the PyAstro for GIMP plugins (https://stargazy.weebly.com/pyastro-for-gimp.html). 
These plugins use Python and my system is macOS 11.7.10.
They work perfectly on GIMP v. 2.10.32.
But they don’t work at all on GIMP v. 2.10.34.
The error is located in the scripts at : from gimpfu import *
Is the gimpfu file missing in GIMP v. 2.10.34 ?

I wrote a python script that removes a background colour from an image, orientates the remainder, resizes the image and then overwrites the existing image file. All of the functions work as expected...but they don't happen in the order expected. The final two lines (below) happen in reverse order.

Quote:    pdb.gimp_image_resize(imageToBeResized, 900, 1500, widthoffset, heightoffset)
    pdb.gimp_file_save(imageToBeResized, drawable, imageFileName, imageFileName)

1. Running the second line twice makes no difference - it will continue to overwrite without resizing.
   
2. Duplicating both lines (1,2,1,2) actually shifts the affected area so that it saves in 900*1500 but to the image focus' upper left.
   

Quote:def postmatch_resize(image):
    imageFileName = pdb.gimp_image_get_filename(image)
    imageToBeResized = gimp.image_list()[0]
    drawable = pdb.gimp_image_active_drawable(imageToBeResized)
    pdb.gimp_image_crop(imageToBeResized, 1900, 1500, 0, 0)
    colorToDelete1 = gimpcolor.RGB(9, 246, 57)
    colorToDelete2 = gimpcolor.RGB(6, 185, 42)
    colorToDelete3 = gimpcolor.RGB(7, 216, 50)
    colorToDelete4 = gimpcolor.RGB(4, 123, 28)
    colorToDelete5 = gimpcolor.RGB(5, 154, 35)
    colorToDelete6 = gimpcolor.RGB(3, 93, 21)
    colorToDelete7 = gimpcolor.RGB(2, 62, 14)
    pdb.gimp_image_select_color(imageToBeResized, 0, drawable, colorToDelete1)
    if pdb.gimp_selection_is_empty(imageToBeResized) == False:
        pdb.gimp_edit_clear(drawable)
    pdb.gimp_image_select_color(imageToBeResized, 0, drawable, colorToDelete2)
    if pdb.gimp_selection_is_empty(imageToBeResized) == False:
        pdb.gimp_edit_clear(drawable)
    pdb.gimp_image_select_color(imageToBeResized, 0, drawable, colorToDelete3)
    if pdb.gimp_selection_is_empty(imageToBeResized) == False:
        pdb.gimp_edit_clear(drawable)
    pdb.gimp_image_select_color(imageToBeResized, 0, drawable, colorToDelete4)
    if pdb.gimp_selection_is_empty(imageToBeResized) == False:
        pdb.gimp_edit_clear(drawable)
    pdb.gimp_image_select_color(imageToBeResized, 0, drawable, colorToDelete5)
    if pdb.gimp_selection_is_empty(imageToBeResized) == False:
        pdb.gimp_edit_clear(drawable)
    pdb.gimp_image_select_color(imageToBeResized, 0, drawable, colorToDelete6)
    if pdb.gimp_selection_is_empty(imageToBeResized) == False:
        pdb.gimp_edit_clear(drawable)
    pdb.gimp_image_select_color(imageToBeResized, 0, drawable, colorToDelete7)
    if pdb.gimp_selection_is_empty(imageToBeResized) == False:
        pdb.gimp_edit_clear(drawable)
    pdb.plug_in_autocrop(imageToBeResized, drawable)
    preheight = pdb.gimp_image_height(imageToBeResized)
    prewidth = pdb.gimp_image_width(imageToBeResized)
    heightoffset = 1500 - preheight
    widthoffset = (900 - prewidth)/2
    pdb.gimp_image_resize(imageToBeResized, 900, 1500, widthoffset, heightoffset)
    pdb.gimp_file_save(imageToBeResized, drawable, imageFileName, imageFileName)

Hi All

So I have an image with a blank white space and a hand around it, I am selecting the white space and now want it to add an image into that white space, adjusting for perspective etc. Is this possible in gimp? I am aware of how to do it manually, was hoping of a quicker method

There's a very useful function in Adobe Photoshop Elements called Photomerge - this allows you to scan a very large document in several images and then combine them into a single image by just opening each one in the program and choosing the Photomerge tool. There are variations in the tool like Exposure or Panorama - it is the Panorama one I'm particularly interested in. I haven't been able to find anything similar in function or simplicity in GIMP - can anyone tell me if a Photomerge function is available in GIMP please?

I'm currently using Gimp 2.14 on Windows 11. I am having trouble with the selection tool. This is a problem with all selection tools (rectangular, oval, cage, freehand, ect). 

Old behavior (desired): Click selection tool. Select the area of the canvas you want. Work inside the area. Click outside of the selected area. The area is un-selected. To add to the selected area, hold + and select a second area. To remove from the selected area, hold - and select the area to un-select. If no area has been selected, you may work on the entire canvas.

New behavior (make it stop!): Click selection tool. Select the area of the canvas you want. Area remains selected until you un-select it manually. To un-select you hold - and select the area you want to have un-selected. Unless an area has been selected, no tools will work on the canvas. You must select the entire canvas to be able to work on the entire canvas. If the entire canvas has been selected, you must un-select the entire canvas manually to be able to select a small part of the canvas.

The new behavior has been a nightmare for my workflow. I am constantly being forced to zoom out and remove all selected areas manually. I also have to constantly reselect the entire canvas so I can get back to work on the bigger picture. It's tedious and very annoying.

How do I get the old behavior back?

Hi
i used to use in photoshop a tool which was able to transform a polygon with 4 sides to a rectangle. on ordre toi make perspective disappear. you juste select the 4 points if the polygon and then activate the function and you obtain a rectangle.
i no longer have photoshop and need this fonction.
does it exist in the
Gimp ?
thanks for your help !

Is there a tutorial here on how this tool can be utilised. I am pretty sure I have seen it talked about on here. I know I could probably find one at You Tube but yours would be sufficient. Don't need to go to Davies Media for all my info.

Hi, I wish to automate an action that takes actually 6 click, to only 2 clicks , This is what I'm thinkinf of :
I click on a new "button" (I need your help to create it) that opens a setting windows. Then I can choose a kind of shape (circle/ellipse/square) to draw a shape on an image, then click on valid. The result is a blur added on the shape

(Instead of clicking on the shape button in the tool box, then select a zone on the image, then click on the Filters menu, then click on Blur, then click on Gaussian blur, then choose the level of blur, then valid.)

Thanks for your help (I don't know anything about programming!