I have trouble with bbox position and font size

[DonSudak]

Hi everyone
I have trouble with bbox position and font size
When im trying to insert text box into pdf page with font size more than 20 there are offset by Y axis

Your configuration (mandatory)

• arch linux
• Python 3.10.9
• PyMuPDF 1.21.1 from pip

[JorjMcKie]

This is a typical "Discussions" post, so let me first transfer it to there.

[DonSudak]

thx and sorry

[JorjMcKie]

Please be more specific! We would need an example code and output at least.

[DonSudak]

in blue border points that i give
in red border points after "page_without_text.insert_textbox"

def Fill_Template(
        cls,
        page_with_text,
        words,
        page_indx,
        templates_without_text,
        file,
    ):
        doc_without_text = fitz.Document(templates_without_text.path)
        page_without_text = doc_without_text[page_indx]
        new_word_list = []

        for word in page_with_text.words:
            text = cls.Fint_and_Replace_Words(word.word, words)
            if "" == text:
                continue
            new_word_list.append(
                New_Word(
                    word=text,
                    font=word.font,
                    font_size=word.font_size,
                    font_color=word.font_color,
                    line_position=word.line_position,
                    box_position=word.box_position,
                ),
            )

        for word in new_word_list:
            font = fitz.Font(fontfile=cls.findFontFile(word.font))
            text_lenght = font.text_length(
                text=word.word,
                fontsize=word.font_size,
            )
            word_box_position = word.box_position
            if word.box_position[0] > (page_with_text.width / 2):
                if word.box_position[0] + text_lenght > word.box_position[2]:
                    offset = (word.box_position[0] + text_lenght) - word.box_position[2]
                    offset_point = word.box_position[0] - offset
                    word_box_position = (
                        offset_point,
                        word.box_position[1],
                        offset_point + text_lenght,
                        word.box_position[1] + word.font_size,
                    )
            else:
                word_box_position = (
                    word.box_position[0],
                    word.box_position[1],
                    word.box_position[0] + text_lenght,
                    word.box_position[1] + word.font_size,
                )
            hex_color = hex(word.font_color).replace("0x", "")
            if len(hex_color) < 6:
                hex_color = "0" + hex_color
            hex_color = "#" + hex_color
            page_without_text.insert_textbox(
                rect=word_box_position,
                buffer=word.word,
                fontname=word.font,
                fontfile=cls.findFontFile(word.font),
                fontsize=word.font_size,
                color=colors.hex2color(hex_color),
            )
            print(word.font_size)
            print(word_box_position)
        print(page_without_text.get_text("dict"))
        doc_without_text.save(f"{file}.pdf")

[JorjMcKie]

thx and sorry

no problem 😊

[JorjMcKie]

Still don't really understand. Is this a new page?
Or do you insert into an existing page? If yes, you may have to do page.clean_contents() directly after loading the page.

[JorjMcKie]

have you tried page.clean_contents() before doing any inserts on that page?

[DonSudak]

didn't help

[DonSudak]

it's so strange
i have page with one shape and insert text boxes with information from other page( font, color, position ) to it
there are pdf file to insert text to it

page.pdf

[JorjMcKie]

Trying this script works perfectly:

import fitz

ffile = "BebasNeue-Regular.ttf"
font = fitz.Font(fontfile=ffile)
fsize = 35
text = "just for testing"
tl = font.text_length(text, fontsize=fsize)
doc = fitz.open("page.pdf")
page = doc[0]
rect = fitz.Rect(10, 10, 10 + tl + 5, 10 + fsize)
page.insert_font(fontname="F0", fontbuffer=font.buffer)
page.draw_rect(rect, color=(1, 0, 0))
page.insert_textbox(rect, text, fontname="F0", color=(1, 0, 0), fontsize=fsize)
doc.ez_save("x.pdf")

[DonSudak]

pasted to script own values
values like in my script
page size of documents are the same

import fitz

ffile = "BebasNeue.otf"
font = fitz.Font(fontfile=ffile)
fsize = 86
text = "64"
tl = font.text_length(text, fontsize=fsize)
doc = fitz.open("page.pdf")
page = doc[0]
rect = fitz.Rect(
    214,
    117,
    283,
    204,
)
page.insert_font(fontname="F0", fontbuffer=font.buffer)
page.draw_rect(rect, color=(1, 0, 0))
page.insert_textbox(rect, text, fontname="F0", color=(1, 0, 0), fontsize=fsize)
print(page.get_text("dict"))
doc.ez_save("x.pdf")

x.pdf

[DonSudak]

i gave all needed values
and only text box in right bottom corner with big font have trouble with y axis position

[DonSudak]

for me it's:
-1.44 point on y axis for every 10 points of font size
i mean if text box in right bottom corner(only for that box) has font size: 60.0 and position: (132.70899963378906, 83.69829559326172, 208.36499923467636, 147.69829559326172)
then the actually position will be (132.70899963378906, 75.05830383300781, 203.98899841308594, 139.4383087158203)
the difference between two Y0 positions will be 8,63999176025
i really can't understand how it works...
there no changes that my code could make
i think so...

[JorjMcKie]

Well that rectangle is outside the page rectangle ... for the most part.
Of course you are getting junk upon text extraction.
Page rectangle is

page.rect
Rect(0.0, 0.0, 229.6060028076172, 164.40899658203125)

So the page height is 164. A text of font size 60 will actually need more than 60 in height, because almost every font will need additional room aove and below (scender / descender values). In case of that font, the line height is fontsize * 1.2 = 72 points.

But independently from all that: something in your calculation leads to textboxes outside the page limits. For debugging I would suggest to draw computed rectangles to better crosscheck, that text really lands inside them.

[JorjMcKie]

The "natural" lineheight of bebas is 1.2, the one of Helvetica is 1.374. The insert_textbox() method supports a lineheight parameter. This can be used to enforce a value like replacing 1.2 with another value if that is what you want.

[DonSudak]

yeah thx
it's really much better but in first screenshot(print text boxes in console) position of "222" text box by y axis not the same with position that i gave to insert_textbox function
im not sure that position of text little bit higher
position of rect that contains text is wrong.
can it be caused by font.ascender and font.descender?

[zergb]

The "natural" lineheight of bebas is 1.2, the one of Helvetica is 1.374. The insert_textbox() method supports a lineheight parameter. This can be used to enforce a value like replacing 1.2 with another value if that is what you want.

Is there a way to get "natural" lineheight before insert_textbox? In my testing, the lineheight might be bigger than ascender-descender. So the only way to guarantee text output is repeat insert_textbox with smaller and smaller font size. Which is very inefficient.

[JorjMcKie]

Is there any reason that mandates you to use page.insert_textbox()?
If not, I recommend using insert_htmlbox. This advanced method automatically does your indicated iteration for you and ensures finding a shrink factor which causes fitting the text ... always.
When you inspect the documentation you will find a plethora of other advantages beyond this aspect.

[zergb]

Since I'm generating a image dataset for pdf files. By checking output of page.insert_textbox() I can check the actual font size fit the given rect. Then determine to skip current file if the font size is too small to recognize in image. Thus to control distribution of font size to be in reasonable range.

[JorjMcKie]

can it be caused by font.ascender and font.descender?

Yes, there is no other explanation.

[DonSudak]

thanks you sooo much
i solved my problem by switching insert_textbox to insert_text