Import your bitmap into flash, and click it once. Within the Modify>Bitmap>Trace Bitmap, you will see a bunch of confusing fields. Let’s go through them one at a time.
This number determines the color quality of the bitmap into vector. Given two pixels, pixel A and pixel B, and your color threshold of 5. In determining the color of pixel B by pixel A, if B is 5 or less RGB color values away from A, then B will become the same shade as A in the final trace. Essentially, your color quality is determining how many shades off your pixel is from adjacent ones, and determining whether or not to just make it easier for flash and make it the same color. If your number is 1, then each pixel will be within at least one RGB color of the original bitmap color and adjacent pixels. For 10, each pixel will be within 10 colors of RGB. This number can range up to 500, and as low as 1. A higher range will yield a much lower file and processing size, so keep this in mind.
This number chooses the amount of surrounding pixels to do color threshold checks on. The higher the number, the lower the quality.
This chooses how smooth the outlines of colors are for when there are connecting pixels of similar color from threshold checks. You can choose three different levels, with the “pixel” being the best quality.
This decides how sharp to make corners. Sharper corners yield a straighter look, while few corners will eliminate strong corners. This option is less for performance, and more for the effect you are trying to achieve for your tracing.
What is recommended?
If you are looking for a threshold that tends to hit at a good balance of quality and still looking like the bitmap, I would recommend the following arrangement:
Minimum Area: 1
Curve Fit: Tight
Corner Threshold: Many Corners.
Adjusting the curve fit from there is a good way to see other options for bitmap quality.
If you put your tracing on full quality, you may crash your flash window, or may have to wait for a few minutes for the rendering to finish. If you are running into this problem, this should definitely be an indicator that you are producing a trace that is far too good of quality to produce for the web (of course, your computer could just be really slow, but that’s usually not the case either).
Leaving in Bitmap Form
Sometimes, I would even suggest you just leave the bitmap in bitmap form. Because flash will just read it like a normal bitmap file, it will load quickly and really have no calculations or shapes to render. In some cases, your bitmap can be even smaller that a traced version, and better quality as well.
If you have bitmaps on the screen, it is best to minimize the amount of bitmaps on the screen as once. If at all possible, reuse the same bitmaps over again to minimize file memory. The larger your library, the larger the filesize, so minimize the amount of bitmaps you are importing. Instead of importing four corner pieces, try importing just one, and rotating 4 times. Easy, right?
When you export your movie, you do have the option or changing the overall bitmap compression. Open up File>Publish Settings>Flash Tab, and find the jpeg quality sliding bar. Here, you can set the compression at which flash will compress for runtime (for all bitmaps, not just jpeg). This does not affect the quality of the bitmap; what it does is sets how much compression there should be to lower the swf file size. What happens is that when you export the flash file, it compresses the images into smaller files. The more compression, the lower the file size, but more compression also means more work for flash to decompress the images. So finding a good balance again (80 is good), for compression is important.
Now, when you actually want to affect the image quality, start by right clicking on the image in the library, and selecting properties. You have the same options as the Publish Settings window, except you may also choose to smooth the bitmap, which will analyze your pixels and choose pixel colors based on adjacent pixels.
Remember, if you are importing jpeg, you are already importing an image with compression on it. If you are importing a gif or png, you are importing an image that is lossless, which means that the image has no loss of quality when saved (full pixels). However, flash will automatically compress gif or png as jpg during export, so if you do not want this to happen, you can switch between jpg or lossless through the bitmap properties window.
Anti-aliasing is a way for flash to create better rasters of text, by cutting down on text quality and shading, thus shrinking file size. It is a good habit to get into setting the anti-aliasing for text. To set the alias, select a text, and open the properties panel. You will find a drop down with many options.
Use Device Fonts
This takes the fonts the user has in their own computer, and uses it to generate text. This will keep the flash file smallest, as it imports the user’s fonts at runtime.
This will turn off text smoothing, and save the outlines of all the text of the font. It will fill text in dynamically, and export at the size you desire (dependent on how you import to the library). Note that the quality will suffer due to the blocky type if you choose a low font size at import, but expand your text above the level you set. Your file size will be smaller.
Anti-Alias for Animation
Embedding the font outlines at export and at medium quality, this creates a good balance for animated text. It is not recommended that you use this method for small or static text. The file size is large due to embedding of font outlines.
Anti-Alias for Readability
Embedding the font outlines at export and great quality, this method makes it easiest to read small fonts, but has problems with animation. It is recommended that you do not use this font for animation, but to use it for blocks of text (especially small font sizes).
At times, you may need to set your own anti-aliasing. However, it is not quite necessary unless you are working with very crucial text, such as text on cell phones or portable devices.
Please do not post... this is not the end of the tutorial... (3/4)