The actual hq2x.exe can sorta do this for you. Although it will save in only .tga or .bmp format. You could just convert that to a .png. Download the exe:
http://web.archive.org/web/20070624082212/www.hiend3d.com/hq2x.htmlIt excepts a .tga or .bmp as the input image. I also think it doesn't like 8bit images. Which isn't a problem really, as you can convert 8bit to something higher anyways.
To use the program easily, without the command prompt. Create a shortcut of the hq2x.exe in the same folder as the actual hq2x.exe. Make sure you have the image you want to convert in the same folder as well. Right click the hq2x shortcut, and choose "Properties". You will see a textbox labeled "Target". The target will have the path leading to the actual hq2x.exe.
eg: C:\Programs\hq2x\hq2x.exe
Now, your just gonna add some arguments to the end of it like so:
eg: C:\Programs\hq2x\hq2x.exe your_image.bmp name_of_new_image.bmp
The first argument is the name of the image you want to convert. It has to be .bmp or .tga. The second argument is the desired name of the new converted image it'll create.
Once you have everything in order, click "Ok". Then double click the short cut. It'll create your new hq2x image. In the same folder.
