CODEWITHSUNDEEP
phpexif
Airikr
Airikr

Reputation: 6436

Convert EXIF data to how it should looks like

According to PHP, the EXIF information for a image is 20/10 for F-number, 51/10 for focal length, and 10/150 for exposure. This is not how these values should look like! It should looks like F/2 for F-number, 5, mm for focal length, and 1/150 for exposure. These values are just some examples! Please see this link for how I really mean how it should looks like. Note that I will not use any third party software! Just pure PHP.

Is it possible to convert these values (for example 20/10) to the real values (for example F/2) in PHP? If yes, how can I convert them?

Thanks in advance.

EDIT

The following code convert 150/10 to 150 seconds which is 2 minutes and 30 seconds. This is wrong because I took the photo with 15 seconds shutter. How can I make it to calculate to the correct amount of seconds?

list($d1, $d2) = str_split('/', 'P1220379.JPG');

if($d1 > 0 AND $d2 > 0) {
    $e = $d1 / $d2;
} else {
    $e = 'P1220379.JPG';
}

if($e < 1 AND $e > 0) {
    $e = '1/'.round(1 / $e, 0).' sekunder';
} else {
    $e = round($e, 1).' sekunder';
}

Upvotes: 1

Views: 1988

Answers (2)

Roger Alien
Roger Alien

Reputation: 3080

This is my solution in kotlin if anyone needs

fun convertShutterSpeed(value: String?): String {
    if (value.isNullOrBlank()) {
        return ""
    }
    val split = value.split("/")
    val ed: Float = split[0].toFloat()
    val ed1: Float = split[1].toFloat()

    val fl = ed / ed1

    return if (ed < 0) {
        Math.round(1 / Math.pow(2.toDouble(), fl.toDouble())).toString() + "s"
    } else {
        "1/" + Math.round(Math.pow(2.toDouble(), fl.toDouble()))
    }
}

And here are some tests

@Test
fun convertShutterSpeed() {
    assertEquals("1/8", imageExif.convertShutterSpeed("3/1"))
    assertEquals("1/10", imageExif.convertShutterSpeed("3321928/1000000"))
    assertEquals("1/20", imageExif.convertShutterSpeed("4321928/1000000"))
    assertEquals("1/125", imageExif.convertShutterSpeed("6965784f/1000000"))
    assertEquals("1/250", imageExif.convertShutterSpeed("7965784/1000000"))
    assertEquals("1/320", imageExif.convertShutterSpeed("8321928/1000000"))
    assertEquals("1/400", imageExif.convertShutterSpeed("8643856/1000000"))
    assertEquals("1/640", imageExif.convertShutterSpeed("9321928/1000000"))
    assertEquals("1/800", imageExif.convertShutterSpeed("9643856/1000000"))
    assertEquals("1/1000", imageExif.convertShutterSpeed("9965784/1000000"))
    assertEquals("2s", imageExif.convertShutterSpeed("-1/1"))
    assertEquals("6s", imageExif.convertShutterSpeed("-2584963/1000000"))
}

Values that I got is from Canon images, but it works for other camera models as well.

Upvotes: 0

TheTechGuy
TheTechGuy

Reputation: 17364

"drpain" on this link says

Please note that when resizing images with GD and most image processing scripts or applications you will loose the EXIF information.What I did as a workaround is book this information into MySQL before I re-size images.

His little program below

<?php

$camera = cameraUsed("/img/myphoto.jpg");
echo "Camera Used: " . $camera['make'] . " " . $camera['model'] . "<br />";
echo "Exposure Time: " . $camera['exposure'] . "<br />";
echo "Aperture: " . $camera['aperture'] . "<br />";
echo "ISO: " . $camera['iso'] . "<br />";
echo "Date Taken: " . $camera['date'] . "<br />";

?>

does produce these numbers in correct format, according to him

Will display the following, depending on the data:

Camera Used: SONY DSC-S930
Exposure Time: 1/400
Aperture: f/4.3
ISO: 100
Date Taken: 2010:12:10 18:18:45

Upvotes: 2

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