Cache image format Selection

After generating the AGS cache image, many people should have encountered this problem. The cut image has obvious noise. Sometimes even the slices on the left show normal, and there is a noise on the right, the cause of the difference between the left and right is unknown, but the method for eliminating noise is to use the png32 format to cut the image.

If you have done web design, remember that the PNG image is not compatible with Some browsers, especially the transparency of some formats is difficult to achieve. The official AGS blog recently gave professional suggestions:

Png8-Use this format for overlay services that need to have a transparent background, such as roads and boundaries. PNG 8 creates tiles of very small size on disk with no loss of information. however, you shocould use a different PNG format if your map contains more than 256 colors. imagery, hillshades, gradient fills, transparency, and the Antialiasing caching option can easily push your map over 256 colors.

Png24-You can use this format for overlay services, such as roads and boundaries, that have more than 256 colors (if fewer than 256 colors, use PNG 8 ). do not use PNG 24 if your tiles will be viewed in Internet Explorer version 6 or previous.

Png32-Use this format for overlay services, such as roads and boundaries, that have more than 256 colors. This format creates larger tiles than PNG 24, but the tiles are fully supported in all browsers.

JPEG -use this format for base map services that have large color variation and do not need to have a transparent background. for example, raster imagery tends to work well with JPEG.

it is easy to understand why png8 is prone to noise, because our basemap can easily exceed 256 colors, although the png32 file is relatively larger than the png8 and png24 files, I still prefer it in the formal project and it shows excellent results, the perfect support for mainstream browsers is enough to strengthen our confidence. The large file size can be digested by massive hard disks.

when caching a grid or vector layer, you must first check the slicing Effect in a small part of the map to avoid a complete cut on the computer, after waiting for the last few days, I find that all the work is done. We recommend that you use a high-performance PC or workstation as the cache computer. CPU and stability are the key.