[OpenJDK 2D-Dev] <OpenJDK 2D-Dev> Review request for JDK-8143562: JPEG reader returns null for getRawImageType()

[Philip Race]

The quoted code comment is essentially disclaiming the spec comment.
And the spec. comment is misleading in that it strongly suggests 
getRawImageType
will hand you an ImageTypeSpecifier representing YCbCr when in fact it 
does not.

In fact all these comments and behaviours together seem to suggest that 
there
isn't a consistent view of what should happen here.
- one says we can return something that represents YCbCr
- another says don't add it to the returned list of types because we 
can't support this raw type after all.
- the spec says return something (anything!) no matter how dissimilar 
(implied
    by there being at least one (a non-null return)).

Basically that seems to be all the options except supporting it.
All of these need to line up and agree.

So I think we need to update the spec. below to say something like
"Returns an |ImageTypeSpecifier| indicating the |SampleModel| and 
|ColorModel|
which most closely represents the "raw" internal format of the image.
If there is no close match then a type which preserves the most
information from the image should be returned."

-phil

On 12/8/15, 11:31 PM, prasanta sadhukhan wrote:
> The fix looks good to me.
> The spec says "Returns an |ImageTypeSpecifier| indicating the 
> |SampleModel| and |ColorModel| which most closely represents the "raw" 
> internal format of the image. For example, for a JPEG image the raw 
> type might have a YCbCr color space even though the image would 
> conventionally be transformed into an RGB color space prior to display."
> Also,
> private Iterator<ImageTypeSpecifier>  getImageTypesOnThread(int imageIndex)adds RGB for YcbCr raw type
> case JPEG.JCS_YCbCr:
>   832             // As there is no YCbCr ColorSpace, we can't support
>   833             // the raw type.
>   834
>   835             // due to 4705399, use RGB as default in order to avoid
>   836             // slowing down of drawing operations with result image.
>   837             list.add(getImageType(JPEG.JCS_RGB));
>
>
> Regards
> Prasanta
> On 12/1/2015 3:42 PM, Jayathirth D V wrote:
>>
>> Hi,
>>
>> _Please review following fix in JDK9:_
>>
>> Bug : https://bugs.openjdk.java.net/browse/JDK-8143562
>>
>> Webrev : http://cr.openjdk.java.net/~jdv/8143562/webrev.00/ 
>> <http://cr.openjdk.java.net/%7Ejdv/8143562/webrev.00/>
>>
>> Issue : We are getting null for ImageTypeSpecifier when we use 
>> getRawImageType() API for YCbCr Image.
>>
>> Root cause : When colorspace is YCbCr, there is no condition to 
>> create ImageTypeSpecifier in produce() function
>>
>> Solution : Since we add RGB as default ImageType for YCbCr colorspace 
>> in getImageTypes() API. Followed same approach
>>
>>                     and considering it as RGB in getRawImageType().
>>
>> Thanks,
>>
>> Jay
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/2d-dev/attachments/20151210/78890eda/attachment.html>