PNG is short for Portable Network Graphics It was developed as a replacement for the GIF standard, partly because of legal entanglements resulting from GIF's use of the patented LZW compression scheme, and partly because of GIF's many limitations.
PNG images can either use palette-indexed color or be made up of one or more channels (numerical values directly representing quantities about the pixels). When there is more than one channel in an image all channels have the same number of bits allocated per pixel .The PNG specification always talks about the bit depth of channels.
PNG is superior to GIF in many ways, offering the following features:
- Images are the same size or much smaller than their GIF counterparts when keeping lossless compression
- Support for indexed colors, gray-scale, and RGB .
- Support for 2-D progressive rendering, which is based on pixels rather than lines (as in interlaced GIFs and progressive JPEGs); this means that contents of a progressively rendered PNG file become apparent earlier in the load process
You can convertformat in a command line by HTML Converter Command Line which can make your conversion faster and easier.
HTML Converter Command Line is a powerful converting software.It allows you to create previews or thumbnails of web pages in a number of different formats, such as TIF, TIFF, JPG, JPEG, GIF, PNG, BMP, PCX, TGA, JP2 (JPEG2000), PNM, etc. HTML Converter Command Line also allows you to convert web pages to PDF, PS (postscript), WMF, EMF vector formats.
You can download HTML Converter Command Line at http://www.verypdf.com/htmltools/htmltools.zip.
The following contents are the steps of convertingformat.If you have some problems about this conversion,you can read this article.
1.Run cmd.exe dialog box by clicking button.Then click “run” in the menu to pop up a dialog box.Input “cmd” in “open” edit box and click “OK” button.You can also use the hot key “Windows” + “R” to realize the same function.
2.Input DOS commands in cmd.exe dialog box.The commands contain called program,source file and target file.Please see the following command line.
“htmltools.exe” “input.wmf” output.png
We can take the commands of converting wmf to png format as the interpretations to the command line above if you don’t understand.
"C:\Documents and Settings\admin\Local Settings\Temp\htmltools\htmltools.exe" "C:\Program Files\Microsoft Office\CLIPART\PUB60COR\AN00790_.WMF" "C:\Documents and Settings\admin\Desktop\New Folder1.png"
"C:\Documents and Settings\admin\Local Settings\Temp\htmltools\htmltools.exe" is the directory of htmltools.exe.
"C:\Program Files\Microsoft Office\CLIPART\PUB60COR\AN00790_.WMF" is the directory of source file.
"C:\Documents and Settings\admin\Desktop\New Folder1.png" is the directory of target file.
NOTE of called program and source file:If you dislike to input the long path in cmd.exe dialog box,you can drag the file you need into the dialog directly.You will find the file will turn to the path of itself.
NOTE of target file:You can specify the target file yourself.If not,you will find the target file saved in current directory.
3.Find the target file in specified location after converting wmf to png format file.