pdfbox get begintext section (BT ET) coordinates

StackOverflow https://stackoverflow.com/questions/6802586

Question

can someone please help me with getting real pixel coordinates for pdf begintext sections? I am using pdfbox to retrieve texts from pdf files but now i need to get rects sorounding that text sections/paragraphs.

$contents = $page->getContents();
$contentsStream = $page->getContents()->getStream();
$resources=$page->getResources();
$fonts = $resources->getFonts();
$xobjects = $resources->getImages();
$tokens=$contentsStream->getStreamTokens();

  • [PDFOperator{q}, COSFloat{690.48}, COSInt{0}, COSInt{0}, COSFloat{633.6}, COSInt{0}, COSInt{0}, PDFOperator{cm}, COSName{im1}, PDFOperator{Do}, PDFOperator{Q},

  • PDFOperator{BT}, COSInt{1}, COSInt{0}, COSInt{0}, COSInt{1}, COSFloat{25.92}, COSFloat{588.48}, PDFOperator{Tm}, COSInt{99}, PDFOperator{Tz}, COSName{F30}, COSInt{56}, PDFOperator{Tf}, COSInt{3}, PDFOperator{Tr}, COSFloat{0.334}, PDFOperator{Tc}, COSString{Pospremanj}, PDFOperator{Tj}, COSInt{0}, PDFOperator{Tc}, COSString{e}, PDFOperator{Tj}, COSFloat{9.533}, PDFOperator{Tw}, COSString{ i}, PDFOperator{Tj}, COSFloat{6.062}, PDFOperator{Tw}, COSFloat{0.95}, PDFOperator{Tc}, COSString{ ciscenj}, PDFOperator{Tj}, COSInt{0}, PDFOperator{Tc}, COSString{e }, PDFOperator{Tj}, COSInt{1}, COSInt{0}, COSInt{0}, COSInt{1}, COSFloat{55.68}, COSFloat{539.76}, PDFOperator{Tm}, COSInt{0}, PDFOperator{Tw}, COSFloat{0.262}, PDFOperator{Tc}, COSString{uoè}, PDFOperator{Tj}, COSInt{0}, PDFOperator{Tc}, COSString{i}, PDFOperator{Tj}, COSFloat{5.443}, PDFOperator{Tw}, COSFloat{-2.145}, PDFOperator{Tc}, COSString{ zimslco}, PDFOperator{Tj}, COSInt{0}, PDFOperator{Tc}, COSString{g}, PDFOperator{Tj}, COSFloat{7.202}, PDFOperator{Tw}, COSFloat{-0.148}, PDFOperator{Tc}, COSString{ odmor}, PDFOperator{Tj}, COSInt{0}, PDFOperator{Tc}, COSString{a }, PDFOperator{Tj}, PDFOperator{ET},

  • PDFOperator{BT}, COSInt{1}, COSInt{0}, COSInt{0}, COSInt{1}, COSFloat{6.72}, COSFloat{513.12}, PDFOperator{Tm}, COSInt{0}, PDFOperator{Tw}, COSName{F30}, COSInt{14}, PDFOperator{Tf}, COSString{}, PDFOperator{Tj}, COSFloat{2.751}, PDFOperator{Tw}, ...

i would like to get output something like PrintTextLocations function does for every word/character. I can get bottom and left coordinate, but how to get width and top coordinate?

PrintTextLocations:

  • string[25.92,45.119995 fs=56.0 xscale=55.440002 height=40.208004 space=15.412322 width=36.978485]p string[63.22914,45.119995 fs=56.0 xscale=55.440002 height=40.208004 space=15.412322 width=33.87384]o string[97.43364,45.119995 fs=56.0 xscale=55.440002 height=40.208004 space=15.412322 width=30.824646]s string[128.58894,45.119995 fs=56.0 xscale=55.440002 height=42.168 space=15.412322 width=33.87384]p string[162.79344,45.119995 fs=56.0 xscale=55.440002 height=42.168 space=15.412322 width=21.566162]r string[184.69026,45.119995 fs=56.0 xscale=55.440002 height=42.168 space=15.412322 width=30.824646]e string[215.84557,45.119995 fs=56.0 xscale=55.440002 height=42.168 space=15.412322 width=49.286148]m ...
Was it helpful?

Solution

...as BT section gives you bottom left coordinates, you need to parse trough all words/letters contained in current BT block to get all other coordinates. First word height + BT bottom = top, max (left coordinate+width) = right, last word bottom = bottom coordinate.

i hope this helps someone...

Example string for a single letter:

string[32.94,35.099976 fs=8.0 xscale=1.0 height=4.4240003 space=2.2240002 width=3.959999]p

Extracted, parsed and prepared line:

32.94,35.099976 fs=8.0 xscale=1.0 height=4.4240003 space=2.2240002 width=3.959999

Function:

/**
 * Parse single word / letter element
 *
 * @param string $str_raw  Extracted word string line.
 * @param string $str_elem Element of interest, word, char.
 * @param int    $pdf_w    Pdf page width.
 * @param int    $pdf_h    Pdf page height.
 * @param int    $pdf_d    Pdf page dpi.
 * @param int    $pdf_r    Pdf page relative dpi.
 *
 * @return array
 */
function createRealCoordinates($str_raw, $str_elem, $pdf_w, $pdf_h, $pdf_d = 400, $pdf_r = 72)
{
    $stringstrip = array('fs=', 'xscale=', 'height=', 'space=', 'width=');
    $string_info = str_replace($stringstrip, '', $str_raw);

    $coord_info = explode(' ', $string_info);
    $coord_xy   = explode(',', $coord_info[0]);

    $coord = array(
        'pdfWidth'  => $pdf_w,
        'pdfHeight' => $pdf_h,
        'pdfDpi'    => $pdf_d,
        'pdfRel'    => $pdf_r,
        'word'      => $str_elem,

        'x1' => null,
        'y1' => null,
        'x2' => null,
        'y2' => null,

        'fontSize'     => null,
        'xScale'       => null,
        'HeightDir'    => null,
        'WidthDir'     => null,
        'WidthOfSpace' => null,
    );

    // Left, Bottom coordinate.
    $coord['x1'] = ($coord_xy[0] / $pdf_r) * $pdf_d;
    $coord['y2'] = ($coord_xy[1] / $pdf_r) * $pdf_d;

    $coord['fontSize']     = $coord_info[1]; // font size.
    $coord['xScale']       = $coord_info[2]; // x size scale.
    $coord['HeightDir']    = $coord_info[3]; // height.
    $coord['WidthDir']     = $coord_info[5]; // word width.
    $coord['WidthOfSpace'] = ($coord_info[4] / $pdf_r) * $pdf_d; // width of space.

    // Right, Top coordinate.
    $coord['x2'] = $coord['x1'] + (($coord['WidthDir'] / $pdf_r) * $pdf_d);
    $coord['y1'] = $coord['y2'] - (($coord['HeightDir'] / $pdf_r) * $pdf_d);

    return $coord;
}

-matija kancijan

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