Flash Templates Tutorials - PNG Properties
Configuring PNG properties
PNG is the only bitmap format with a crossed platform supporting transparency (alpha channel). It is also the native file format for Macromedia Fireworks. Flash exports first clip frame as PNG, if you do not check other keyframes for export by checking Static frame box.
PNG settings properties management in Publish Settings dialog box
Dimensions - Sets the size of the exported bitmap image in pixels, which you enter in the fields Width and Height. If you enable Match Movie, entering any data into the fields Width and Height has no effect, and Flash makes PNG at the same size as the clip. Flash ensures that the size that you determine always has the same compression ratio as your original image.
Bit Depth - determines the number of bits in the pixel to use in creating an image. Bit depth determines the number of colors to be used in the image. For 256 - color image, select 8 - bit; for thousands of colors, select the 24 - bit; for thousands of colors with transparency (32 bits) choose 24 – bit with Alpha. The higher the bit depth, the larger the file is.
Options - identify the range of settings for the exported PNG.
Optimize Colors - removes any unused colors from the colors table of PNG file. It can reduce the size of PNG file to 1000-1500 bytes without losing image quality. However, it requires a small increase of memory usage. Please note that this option has no effect with an adaptive palette.
Smooth - enables or disables smoothing within the exported dotted image. Smoothing produces a bitmap image of higher quality. Text quality of the display looks poor without smoothing. But there may appear an image grey ghos placed on a colored background. Export without smoothing, if there is an image ghost, or create a transparent PNG which will be placed on top of the multicolored background. Disabling this option makes it PNG files smaller.
Interlace - makes the exported PNG file upgradable while loading. Interlaced PNG provides the user with a basic graphical content before the file is fully loaded and can be quickly loaded on a slow network connection.
Dither Solids - applies the transfer of semitones to the solid colors as well as to gradient images.
Transparent - shows transparent PNG. Transparent PNG allows your browser to show the background through the parts of PNG where there are no images. If you create a transparent PNG, set the background color be selecting Modify / Movie to make it correspondent to the page background. Use smoothing properties to optimize a color match.
Remove Gradients - converts all gradients, fills the clip with solid colors, used as the first color in gradients. Gradients increase the size of PNG, and often have poor quality. When using this option, you must select the first color of your gradients carefully to prevent the unexpected results. The default value is false.
Dither - enables or disables the transfer of semitones and determines the method of transfer of semitones in pixels in the range of similar colors in order to simulate colors that are not available in the current palette. When transferring semitones from Flash, colors not from the main table but from the table with solid colors, which most closely approximate the requested color, are replaced; without transferring semitones you may produce smaller files, but check the results to see whether the colors are satisfactory. Transferring semitones may help if the transparent image contains objects. Transferring semitones increases the size of the file. None parameter disables the transfer of semitones.
Ordered - provides transfer of semitones of good quality to the least possible increasing of the file size.
Diffusion - provides the better quality of semitones transfer, but increases the file size and the processing time is longer than with custom transfer semitones. This only works with 216 color palette.
Palette Type - determines the color palette used for the image. You can select from the following: Web 216 uses standard 216 - color secured palette of the browser to create a PNG image. This provides good image quality and the fastest processing on the server. Adaptive analyzes colors in the image and creates a unique color table for a specific PNG. This creates the most accurate color for the image, but the final PNG file size is larger than PNG established with web 216 - color palette. You can reduce PNG size established with adaptive palette by reducing the number of colors in the palette. Adaptive palette works best for the systems, displaying thousands or millions of colors. Web Snap Adaptive is the same as Adaptive palette, except that it converts color close to Web 216 color palette. The final color palette is optimized for the image, but when possible, Flash uses colors in Web 216. When Web 216 palette is active at 256 - color system, it produces best colors for the image. Custom allows you to determine a palette that you have optimized for the current image. To use this option, you must be familiar with the creation and use of custom palettes. To select a custom palette, click a button tagged with (...) sign at the right from the field Palette at the bottom of the dialog box, and select the palette file. Flash supports palettes saved in ACT format. It is the same format used by Macromedia Fireworks and other key applications working with graphics.
Max Colors - sets the number of colors used in GIF image. Selecting fewer colors can produce a smaller file, but can degrade the quality of the colors in the image. You can set the value for max colors only when you have selected Adaptive or Web Snap Adaptive as options of Palette Type.
Filter Options - identify the filter method for PNG. Before the compression, PNG image is filtered line by line to make it more compressed. Compare the results of the various options to see what works best for a specific image. Filtering options standard PNG: None does not provide any filtering. Sub passes the difference between each byte and value of the corresponding byte of the preceding pixel. Up forwards the difference between each byte and the value of the corresponding byte of the subsequent pixel.
Average - uses the average number of the two adjacent pixels (left and upper) to predict the pixel value. Paeth calculates a simple linear function of the three adjacent pixels (left, top, top left), then selects the neighboring pixel closest to the calculated value.