save as: jpg or bmp?

[cheez]

Howdy, I feel like I need to say again how grateful I am for this forum.

If I had a choice to save an image as a bitmap or a jpeg for use as an mc in Flash, which would it be? How about if it was for use as just a graphic? It most likely will be static background. Clarity and resolution of very important. Possibly resizing 2-3x larger would be involved.

Thanks,
Cheez

[snapple]

jpg's are much lighter and are better quality, so i really would stick with them if you can.

regards, snapple :)

Happy new year

[pixelwit]

When bringing raster images into Flash it's probably best to have them at their final size and with as much color detail as possible. This means no lossy compression (which means no JPG's).

When Flash exports your image to a SWF it will re-compress your JPG (unless you created the JPG with Macromedia Fireworks) which results in a lower quality image than an image that's only been compressed once.

Using a non-compressed image also gives you the flexibility to set your image compression levels as high or as low as you like when publishing your SWF file. But on the other hand using a JPG means you can never publish your SWF with a higher quality setting than your original JPG (well, you can but it won't look any better than the original imported JPG).

You can set how much Flash compresses an image by right-clicking the image in the Library or by choosing PublishSettings-Flash-JPEGQuality.

Hope it helps,

-PiXELWiT
http://www.pixelwit.com

[Ricod]

So cheez, it depends. If you go for quality, go with bmps. If you're gonna load on the fly, jpegs it it, unless quality is the most important thing (for instance a portfolio site for a photographer)

[pixelwit]

You're talking about importing images into the Flash authoring environment right? Because I don't think you can load a BMP into a SWF "on the fly".

Just to make sure I wasn't talking out of my butt earlier, I did a little test.

I took an uncompressed raster image and saved it as "BMP.bmp". I saved another version of "BMP.bmp" as "JPG60.jpg" and used a compression setting of 60%. I saved another version of "BMP.bmp" as "JPG20.jpg" and used a compression setting of 20%. BMP.bmp looks real good, JPG60.jpg looks adequate and JPG20.jpg looks chunky. I imported all three images into Flash and opened the Library panel then tweaked the compression settings of each image until they produced (chunky but small) 10k files. You can do this by opening the library, double-clicking the iamge's icon, un-checking "use document default quality", entering a number into the "quality" box and pressing "Test" until you get the desired results. I then published the file (attached).

Left is "JPG20", middle is "JPG60" and right is "BMP". If you zoom in you can see that image quality is increased as initial compression is reduced.

If you want the highest image quality you can get from a given file size (you did say clarity and resolution were important) start with an uncompressed raster image.

I guess geeks say "garbage in, garbage out" for a reason. :)

Hope it helps,

-PiXELWiT
http://www.pixelwit.com

[cheez]

Wow, thanks ricod, snapple, pixelwit for the input. My own quick impression was when I was saving an image off the 'net. I could save it as a bmp or jpeg. I imported into the library and used them in a scene. I both cases the images, in the way I wanted them, were too small. Resizing allowed me to see that the bmp became more pixelated sooner than the jpg.

Hehe, Pix, I did see that in your comparisons.swf, the bitmap looked the best! Your test, how should we say, had a little bit more scientific backbone than mine! Well done. Thanks.

When this comes up again, I'll let y'all know what happens.

See ya,
Cheez

[Ricod]

I'm pretty sure you've just helped a lot of people pixelwit ! And nobody was talking about 'on-the-fly' stuff, 'cept for me. :) Anyway, also a thank you from myself, cuz I didn't knew this one either !

[cheez]

Hehe, good stuff this forum.

Aw criminy, I forgot to ask, after seeing them images, I says to myself:

"How do I take screenshots again with win2k?"

Either I'm perty dumb or my printscreen ain't workin'. Thought they'd be saved as bmp, no? Hehe, any gentle nudge in the right direction would be much appreciated ;)

-Cheez

Originally posted by Ricod
I'm pretty sure you've just helped a lot of people pixelwit ! And nobody was talking about 'on-the-fly' stuff, 'cept for me. :) Anyway, also a thank you from myself, cuz I didn't knew this one either !

[pixelwit]

Originally posted by cheez
...when I was saving an image off the 'net. I could save it as a bmp or jpeg...Well, that kind of defeats the whole "start with an uncompressed raster image" concept (unless the image you're saving from the web isn't a JPG).

If you're saving an image from the web it's best to leave it in it's native file format. Converting JPG's into BMP's will only result in increasing file size without adding anything to image quality.

What I said before only applies to images which have never been compressed.

Hope that clears things up a bit, and "you're welcome", glad to have helped out some.

-PiXELWiT
http://www.pixelwit.com