Provide access to data offset in WritableRaster in Java 9

[Peter A]

Thanks! I've posted a message to that mailing list and will create a bug
report after a short discussion with them.

- Peter

On Thu, Jul 13, 2017 at 11:22 AM, Phil Race <philip.race at oracle.com> wrote:

> Hi Peter,
>
> 2d-dev would be the right list.
>
> Sounds like you were accessing jdk internals and found that you
> mostly can do away with that except for sub-images.
>
> What you should really do is file an issue at bugs.java.com as
> client-libs/2d for cat/subcat.
>
> If this had been raised earlier in JDK 9 development - we could have
> looked into
> it in time. Now it will have to wait for a follow on release.
>
> -phil.
>
>
> On 07/13/2017 10:47 AM, Alan Bateman wrote:
>
>> The 2d-dev or awt-dev mailing lists may be a better place to bring this
>> up.
>>
>> -Alan
>>
>> On 13/07/2017 17:21, Peter A wrote:
>>
>>> Apologies since this probably not the correct list, but I was referenced
>>> here from another Java list.
>>>
>>> Background:
>>> The high level API in a BufferedImage is very very very slow. To get
>>> around that problem, in previous versions of Java, the internal rasters
>>> which were defined in sun.awt.image were accessed.   Doing so enabled
>>> real-time computer vision in Java.
>>>
>>> Problem:
>>> Accessing the low level Rasters is no longer practical in Java 9.  After
>>> this problem was reported by one of my users I looked into it and found a
>>> work around, for most situations.  Unfortunately the higher level
>>> WritableRaster does not provide access to the offset inside its internal
>>> data array.   This makes processing of subimages impossible.  My
>>> suspicion
>>> is that it is most likely an oversight because it provides access to
>>> every
>>> other piece of information needed and the raw data.    It would be great
>>> if getDataOffset() could be moved into WritableRaster or one of its
>>> parents
>>> instead of being hidden in children of WritableRaster.
>>>
>>> Just to clarify the raw arrays are stored inside of a DataBuffer and that
>>> data structure contains an offset. This offset is always set to zero and
>>> the offset inside of WritableRaster is what is needed,
>>> e.g. IntegerInterleavedRaster.getDataOffsets().
>>>
>>> Thanks,
>>> - Peter
>>>
>>>
>>
>


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