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Fixed normalization of exposure time #43

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Merged
merged 4 commits into from
Aug 12, 2015
Merged

Fixed normalization of exposure time #43

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c3185ba
Fixed normalization of "ExposureTime" (prevent division by zero)
Aug 12, 2015
9cd8186
Updated tests
Aug 12, 2015
eb5a528
Added check for case when exposure time is already a decimal value.
Aug 12, 2015
689a0ac
Cast exposure time to float
Aug 12, 2015
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4 changes: 4 additions & 0 deletions lib/PHPExif/Exif.php
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Original file line number Diff line number Diff line change
Expand Up @@ -346,6 +346,10 @@ public function getExposureMilliseconds()
return false;
}

if (is_numeric($this->data[self::EXPOSURE])) {
return $this->data[self::EXPOSURE] + 0;
}

$exposureParts = explode('/', $this->data[self::EXPOSURE]);

return (int) reset($exposureParts) / (int) end($exposureParts);
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9 changes: 8 additions & 1 deletion lib/PHPExif/Mapper/Exiftool.php
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Expand Up @@ -143,7 +143,14 @@ public function mapRawData(array $data)
}
break;
case self::EXPOSURETIME:
$value = '1/' . round(1 / $value);
// Based on the source code of Exiftool (PrintExposureTime subroutine):
// http://cpansearch.perl.org/src/EXIFTOOL/Image-ExifTool-9.90/lib/Image/ExifTool/Exif.pm
if ($value < 0.25001 && $value > 0) {
$value = sprintf('1/%d', intval(0.5 + 1 / $value));
} else {
$value = sprintf('%.1f', $value);
$value = preg_replace('/.0$/', '', $value);
}
break;
case self::FOCALLENGTH:
$focalLengthParts = explode(' ', $value);
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23 changes: 14 additions & 9 deletions lib/PHPExif/Mapper/Native.php
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Expand Up @@ -150,13 +150,18 @@ public function mapRawData(array $data)
}
break;
case self::EXPOSURETIME:
// normalize ExposureTime
// on one test image, it reported "10/300" instead of "1/30"
list($counter, $denominator) = explode('/', $value);
if (intval($counter) !== 1) {
$denominator /= $counter;
if (!is_float($value)) {
$value = $this->normalizeComponent($value);
}

// Based on the source code of Exiftool (PrintExposureTime subroutine):
// http://cpansearch.perl.org/src/EXIFTOOL/Image-ExifTool-9.90/lib/Image/ExifTool/Exif.pm
if ($value < 0.25001 && $value > 0) {
$value = sprintf('1/%d', intval(0.5 + 1 / $value));
} else {
$value = sprintf('%.1f', $value);
$value = preg_replace('/.0$/', '', $value);
}
$value = '1/' . round($denominator);
break;
case self::FOCALLENGTH:
$parts = explode('/', $value);
Expand Down Expand Up @@ -217,7 +222,7 @@ protected function isSection($field)
*/
protected function extractGPSCoordinate(array $components)
{
$components = array_map(array($this, 'normalizeGPSComponent'), $components);
$components = array_map(array($this, 'normalizeComponent'), $components);

if (count($components) > 2) {
return intval($components[0]) + (intval($components[1]) / 60) + (floatval($components[2]) / 3600);
Expand All @@ -227,12 +232,12 @@ protected function extractGPSCoordinate(array $components)
}

/**
* Normalize GPS coordinates components
* Normalize component
*
* @param mixed $component
* @return int|float
*/
protected function normalizeGPSComponent($component)
protected function normalizeComponent($component)
{
$parts = explode('/', $component);

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17 changes: 13 additions & 4 deletions tests/PHPExif/ExifTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -219,10 +219,19 @@ public function testGetExposure()
*/
public function testGetExposureMilliseconds()
{
$expected = 1/320;
$data[\PHPExif\Exif::EXPOSURE] = '1/320';
$this->exif->setData($data);
$this->assertEquals($expected, $this->exif->getExposureMilliseconds());
$rawData = array(
array(1/300, '1/300'),
array(0.0025, 0.0025),
);

foreach ($rawData as $data) {
$expected = reset($data);
$value = end($data);

$data[\PHPExif\Exif::EXPOSURE] = $value;
$this->exif->setData($data);
$this->assertEquals($expected, $this->exif->getExposureMilliseconds());
}
}

/**
Expand Down
13 changes: 10 additions & 3 deletions tests/PHPExif/Mapper/ExiftoolMapperTest.php
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Expand Up @@ -138,12 +138,19 @@ public function testMapRawDataCorrectlyIgnoresIncorrectCreationDate()
public function testMapRawDataCorrectlyFormatsExposureTime()
{
$rawData = array(
\PHPExif\Mapper\Exiftool::EXPOSURETIME => 1/400,
'1/30' => 10/300,
'1/400' => 2/800,
'1/400' => 1/400,
'0' => 0,
);

$mapped = $this->mapper->mapRawData($rawData);
foreach ($rawData as $expected => $value) {
$mapped = $this->mapper->mapRawData(array(
\PHPExif\Mapper\Exiftool::EXPOSURETIME => $value,
));

$this->assertEquals('1/400', reset($mapped));
$this->assertEquals($expected, reset($mapped));
}
}

/**
Expand Down
36 changes: 33 additions & 3 deletions tests/PHPExif/Mapper/NativeMapperTest.php
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Expand Up @@ -108,12 +108,19 @@ public function testMapRawDataCorrectlyIgnoresIncorrectDateTimeOriginal()
public function testMapRawDataCorrectlyFormatsExposureTime()
{
$rawData = array(
\PHPExif\Mapper\Native::EXPOSURETIME => '2/800',
'1/30' => 10/300,
'1/400' => 2/800,
'1/400' => 1/400,
'0' => 0,
);

$mapped = $this->mapper->mapRawData($rawData);
foreach ($rawData as $expected => $value) {
$mapped = $this->mapper->mapRawData(array(
\PHPExif\Mapper\Native::EXPOSURETIME => $value,
));

$this->assertEquals('1/400', reset($mapped));
$this->assertEquals($expected, reset($mapped));
}
}

/**
Expand Down Expand Up @@ -251,4 +258,27 @@ public function testMapRawDataCorrectlyIgnoresInvalidCreateDate()
$result
);
}

/**
* @group mapper
* @covers \PHPExif\Mapper\Native::normalizeComponent
*/
public function testNormalizeComponentCorrectly()
{
$reflMethod = new \ReflectionMethod('\PHPExif\Mapper\Native', 'normalizeComponent');
$reflMethod->setAccessible(true);

$rawData = array(
'2/800' => 0.0025,
'1/400' => 0.0025,
'0/1' => 0,
'0' => 0,
);

foreach ($rawData as $value => $expected) {
$normalized = $reflMethod->invoke($this->mapper, $value);

$this->assertEquals($expected, $normalized);
}
}
}