[
https://issues.apache.org/jira/browse/IMAGING-285?focusedWorklogId=649792&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-649792
]
ASF GitHub Bot logged work on IMAGING-285:
------------------------------------------
Author: ASF GitHub Bot
Created on: 12/Sep/21 23:11
Start Date: 12/Sep/21 23:11
Worklog Time Spent: 10m
Work Description: gwlucastrig commented on a change in pull request #164:
URL: https://github.com/apache/commons-imaging/pull/164#discussion_r706926789
##########
File path: src/main/java/org/apache/commons/imaging/common/RationalNumber.java
##########
@@ -73,8 +124,41 @@ private static long gcd(final long a, final long b) {
return gcd(b, a % b);
}
+ /**
+ * Negates the value of the RationalNumber. If the numerator of this
+ * instance has its high-order bit set, then its value is too large
+ * to be treated as a Java 32-bit signed integer. In such a case, the
+ * only way that a RationalNumber instance can be negated is to
+ * sacrifice one bit of precision by dividing both the numerator and
+ * the denominator by 2. However, if that computation would result
Review comment:
by the computed greatest common denominator.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
Issue Time Tracking
-------------------
Worklog Id: (was: 649792)
Time Spent: 1h 20m (was: 1h 10m)
> Decoding of Rational Numbers broken when large values present
> -------------------------------------------------------------
>
> Key: IMAGING-285
> URL: https://issues.apache.org/jira/browse/IMAGING-285
> Project: Commons Imaging
> Issue Type: Bug
> Components: imaging.common.*
> Affects Versions: 1.0-alpha2
> Reporter: John Andrade
> Priority: Major
> Attachments: DJI_0267 cropped.JPG
>
> Original Estimate: 1h
> Time Spent: 1h 20m
> Remaining Estimate: 0h
>
> Decoding Lat/Long EXIF data from JPEGs does not work for some values. I have
> attached a file where the conversion fails. I used the
> getLatitudeAsDegreesNorth and getLongitudeAsDegreesEast methods from the
> TiffImageMetaData.GPSInfo class. The values are close, but seemingly off by
> a few miles.
> I've traced the source and I believe the issue is with how the RationalNumber
> class uses two 32-bit signed integers for the numerator and denominator. The
> definition of a RATIONAL data type uses 32-bit unsigned numbers. It seems as
> if the RationalNumber class already expects this as it has a non-public
> static method called factoryMethod to create a RationalNumber from two 64-bit
> numbers.
> This error is introduced in the ByteConversions class, specifically the
> toRational method where it uses the regular RationalNumber constructor and
> thus ensures any rational numbers that have numerator or denominator greater
> than the max signed 32-bit value will produce invalid values.
> I am attaching a JPEG that has this problem. I had to crop it to reduce the
> size, but the EXIF data was preserved.
> The EXIF GPS data contained in the JPEG is:
> GpsLatitudeRef: "N"
> GpsLatitude: 38, 1, 36, 1, 4120083230, 70000000
> GpsLongitudeRef: "W"
> GpsLongitude: 90, 1, 12, 1, 2379156648, 70000000
> According to the properties of the image (right-clicking on Windows 10), the
> L/L of the image is:
> Latitude: 38: 36: 58.85833....
> Longitude: 90: 12: 33.98795... (Windows doesn't show E/W)
> These values convert to:
> 38.616349536627
> -90.2094410978095
> When I use the getLatitudeAsDegreesNorth and getLongitudeAsDegreesEast
> methods, I get the following values:
> 38.59930601561111
> -90.19239757679365
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
