How to replace text in Gimp image programatically-CodePudding

As in the title - imagine there is some Gimp .xcf file containing many layers. Part of these layers contain text. Is there any format I can export .xcf file to, that it somehow preserve 'human readable' text ?

The final goal is to process that text and put it again into the file, I am aware that this sounds unusual but maybe some of you have an idea how to achieve scenario like that.

I did some research and I saw I can export image to .psd format and then using NPM package process that image and extract text. This is just partially solves the problem, because I will not know how to put the processed text back into this .psd file (unless I decompile this NPM package and try to write some implementation myself...)

Any solutions and alternatives higly appreciated

CodePudding user response：

You can script Gimp (using Scheme or Python). Technically you cannot change the text in a layer (there is no API for that), but you can recover the characteristics of a text layer (original text, font type, font size...) and recreate a new layer with a new text. Here is some Python code to recover the text information:

def text_info(img,layer):
    parasites=None
    try:
        parasites=layer.parasite_list()
    except Exception as e:
        pass;
    if parasites and 'gimp-text-layer' in parasites:
        data=layer.parasite_find('gimp-text-layer').data
        pdb.gimp_message('Text layer "%s": %s' % (layer.name,data))
    else:
        pdb.gimp_message('No text information found for layer "%s"' % layer.name)

(this information is only present of the file has been saved, it is not available on a newly created layer, but this shouldn't bea problem in your case)

Of course if the text is in a plain bitmap layer of its own this cannot be done, you have to guess the font type & size (but sometimes the code above can still recover the text information)

But if your XCF has a simple structure, it can be a lot simpler to decompose it into individual images, and build a new image with ImageMagick, using some of these layers plus new text images (or directly rendered text).