PNG and JPEG download Issues

Can anyone give some recommendations as to settings to use when creating a PNG file so that it will download correctly as both a PNG and a JPEG using the default retrieval task of NONE.

I need to upload files as PNG with a transparent background. If I create the PNG as PNG-24, it downloads fine as a PNG file but it ends up a mess when downloading with JPEG retrieval task (black background when it should be white and some other really weird stuff happening). If I create the file as a PNG-8, it downloads fine jpeg retrieval task but loses the transparency if download with default retrieval task of none (works fine with get original).

The requirement is that I upload PNG files that people can download as PNG with transparency (recommended) but also as a JPEG for those that just really have to have them for whatever reason.

The people that will be downloading this are using the system for this purpose only, probably never again, and it needs to be as easy as possible. Telling them to use "GET Original" just won't work as they won't even pay attention to the instructions.

Any advice on this is greatly appreciated.

Stephanie

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Comments

lyman

Unfortunately the JPEG file format has no concept of transparency and so when you convert a transparent PNG to JPEG it is showing the pixels that were in the file but marked transparent.

However, you may be able to use the image compositor primitive (in 4.6.2...preferred) or the watermark adder (prior to 4.6.2...assuming you have AGS) to construct a task that will flatten the PNG onto a white background and then encode as JPEG.

Of course the end users will just see a task called "Get me a JPEG" or some such and will never have to worry about how!

Cheers,

Lyman Hurd

Thils

Unfortunately the JPEG file format has no concept of transparency and so when you convert a transparent PNG to JPEG it is showing the pixels that were in the file but marked transparent.

However, you may be able to use the image compositor primitive (in 4.6.2...preferred) or the watermark adder (prior to 4.6.2...assuming you have AGS) to construct a task that will flatten the PNG onto a white background and then encode as JPEG.

Of course the end users will just see a task called "Get me a JPEG" or some such and will never have to worry about how!

Cheers,

Lyman Hurd

Hi,
I am facing same problem. can you please tell me what is "image compositor primitive (in 4.6.2...preferred) or the watermark adder (prior to 4.6.2...assuming you have AGS) to construct a task that will flatten the PNG onto a white background and then encode as JPEG."

I couldn't understand this .please explain me.

testReport2.rptdesign

lyman

The image compositor puts together two images. If you have a PNG with a transparency channel you could (assuming that the image size is fixed) create a white image in Photoshop and use it as one of the inputs to the compositor (i.e., tell it to make a new image out of your original image and the fixed white image). Somewhat of a kludge I realize but unfortunately we do not have control over the background when rendering PNG's.

Cheers,

Lyman Hurd