iScreensaver Forums

posted 01-12-2003 10:00 AM            

I tried Publishing a SWF with JPEG Quality 10 and 100 and the final iScreensaver movie (800 x 600) was the same size. Do I need to downgrade the original JPEG size that I created in Photoshop (12) and then import them and downgrade them again in the Publish settings?

I read that the minimum size is 2.6 or 2.5 mb—wow! How did you get that? Mine, as discribed above is 7mb no matter what I do.

Help!

posted 01-12-2003 10:10 AM            

There is a certain amoung of software overhead for our screensaver, which as mentioned is about 2.5 MB (which seems rather large, until you realize that this compresses down to about 900K using Stuffit or WinZip).

So, if you are seeing a 7MB final installer size, that means that your SWF file must be about 5.5MB.

Making SWF files smaller is part science and part art, and probably beyond the scope of what we can do here. You may want to get some consulting from some Flash experts?

If you are doing slide shows, you may want to try our 3.0 product which has a built in slide show module; the cool thing is that you can control the compression of EACH Image!

A rule of thumb is that for a full-screen JPEG image (1024x768) it's going to need about 100K-200K to look decent. Therefore, let's say you have 20 images. The final size would be (20 * 100K = 2MB) + overhead (2.5MB) for a total of 4.5MB.

So, you may want to try using a higher compression (lower quality) setting in flash.

Also, don't use too many pixels. If you final slide show is destined for 800x600 size, don't use 1600x1200 images in flash!

posted 01-12-2003 02:49 PM            

I think what you are also telling me though is that it's not absolutely necessary for me to publish a QuickTime movie out of Flash to make it smaller, the SWF format is perfectly acceptable? I saw a reference to that in another post somewhere here.

posted 01-12-2003 03:54 PM            

quote:

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I think what you are also telling me though is that it's not absolutely necessary for me to publish a QuickTime movie out of Flash to make it smaller, the SWF format is perfectly acceptable? I saw a reference to that in another post somewhere here.
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posted 01-12-2003 05:34 PM            

COMPRESSION UTILIZING PUBLISH SETTINGS
1. Photo’s out of Photoshop (800 X 600 @ 72 DPI) were saved as JPEG Quality 12.
2. Import into Flash and place on timeline (800 x 600 @ 1 fps).
3. Go into Publish settings and publish one set with JPEG Quality set to 100 and another Published at Quality 10. File size difference is nada! Both SWF’s were exactly the same size (4.8 mb) and image quality was fantastic. Why? Because there’s no compression applied to the images that came from Photoshop.

COMPRESSION BY DISABLING JPEG DATA
1. The second time around, I imported the same photos accept this time I disabled the “Use imported JPEG data” check box. The default Quality level was set to 50. I left it there.
2. I continued to disable the JPEG data check box and let the default of 50 stand for each of the 10 images.
3. In the Publish settings, I set the JPEG Quality to 100 then published the file.

The SWF that came from the disabling process was only 516k and looked just as the 4.8 mb version. Just for kicks, I changed the Publish JPEG Quality setting from 100 to 10. There was a little bit of image difference but not a great deal. The file size on the other hand barely changed at all going from about 516k to about 510k! So much for the Publish settings.

I’m going to guess that if I had imported Pict files instead of JPEGs the Publish settings would have made a difference—but because I don’t feel like testing it right now I’ll have to leave that as speculation. Anyway my final screen saver installer came out to 3.1 mb instead of the 7 mb I would have had by importing the 4.8 mb swf into iScreensaver.

Now, the only other question I have has to do with Stuffing. It was mentioned that a 2.6 mb file could be Stuffed down to about 900k. How in the world did you do that? I put my installer file into DropStuff and it only went down to 1.6 as a .bin and 2.2 as an .hqx. Are you compressing it from within a full version of Stuffit and if so, what are you doing to make it so small? Are there special settings? I used to have a full version (about 8 years ago) but I never noticed a difference between what would get stuffed using the full version and the free version that could be downloaded from the web. Please give me a clue.

I learned another important thing about image quality while doing this exercise —NEVER SCALE AN IMPORTED RASTER IMAGE! I had placed a logo in my fla file. As each image appeared, I would have the logo placed in a different location of the photo and at a different size—I started with an oversized logo and just scaled it down to fit the area I was addressing. When I viewed the render, the edges of the logo appeared to stair-step. So I went back into Photoshop and made two additional, smaller versions of the same logo, each half the size of the previous one. Imported them and replaced the scaled versions—What a difference!!

posted 01-12-2003 05:53 PM            

Again, excellent info. (Maybe you should apply for a job here? Just kidding :-) )

In any case, I'll make another plug for iScreensaver Designer 3.0. (just about to be released). It has built in support for JPEG compression, and you can see the results in realtime on your screen. Here's a teaser of our interface...:

posted 01-12-2003 06:11 PM            

BTW: I'm unemployed right now—not kidding.

posted 01-12-2003 06:45 PM            

quote:

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Originally posted by mgilvey:
Oh, you didn't answer my question about Stuffit. Second to last paragraph in my novel before your screen shot post.

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Sorry,
The 900K number was pulled from memory, and may have been for the windows installer size. I think about 1.1MB is the base mac stuffed size, so if you are seeing 1.6MB that sounds about right. Unfortunately, JPEGs don't compress AT ALL (they are already fully compressed).