Hi, readers & friends!
Information below will be useful for the Adobe Flash Professional users.

To achieve a satisfying balance between file size and quality of images in your Flash Pro project, you should tune the compression settings for every image you have in your project. As you could know, compression setting could be tuned via the “Bitmap Properties” dialog available from the library image context menu.
So, in case of JPEG images compression, Flash Pro could put JPEG images into SWF without recompressing (use original JPEG) or recompressing them with a custom quality.
Some time ago I searched the web for the clear explanation in which cases Flash Pro offers to use original JPEG (“Use imported JPEG data” option button) and in which – recompress it (“Use publish settings”) to code the original JPEG using detect rule in my XFLTool. Unfortunately, I didn’t find what I searched for, so I asked guys from Adobe about this and got a really clear and fast answer!

I’ll describe it shortly:
– we see the “Use imported JPEG data” radio button only if image is a JPEG and not progressive or arithmetic coded and not in the Grayscale, CMYK or YCCK color spaces, otherwise we see the “Use publish settings” option button
– exporting an image from Flash Pro will cause the image to be rendered and then encoded in the output format and you will lose whatever type of formatting you had before for that image
– we can’t detect JPEGs with the “Use imported JPEG data” option button neither from XFL, nor form JSFL – there is no way to do it at this moment

I’d like to thank all people from Adobe assisted me gathering this information.

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