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glViewImage is an image viewer, converter and even a very limited editor.
glViewImage was originally developed to test and demonstrate the power of image handling inside our VRML engine, but it became quite usable utility on it's own. Viewed image can be quickly scaled and moved, you can browse images list, you can test how image looks when tiled (to test is it good for a texture or desktop wallpaper), you can see how alpha channel of the image looks on various background colors. The ability to load and save even some uncommon image formats (DDS, RGBE) is also very useful.
Various image formats are supported:
These are the binaries of the program. No special installation is required, just unpack the archive and run glViewImage.
You can simply run the glViewImage without parameters, and open / save images using the menu commands.
| Keys not available as menu items: | |
|---|---|
| Arrows | move image |
| Arrows + Ctrl | move image 10 x faster |
| - / + | scale image (smaller / larger) |
| x / X | scale only horizontally (smaller / larger) |
| y / Y | scale only vertically (smaller / larger) |
Notes about opening image: glViewImage guesses image format using file extension (yes, yes, I will change it at some time to recognize image format based on file content), so it's important for files to have good filename extension. JPEG images may have extension jpg or jpeg, RGBE images - rgbe or pic, rest is obvious.
Opened image is also added to the image list.
glViewImage remembers image list that you can browse using N (next image on the list) and P (previous image on the list) keys. When you run glViewImage you can give it as parameters a list of images to browse.
Every parameter must be one of:
A directory name — glViewImage will display all images found in this directory.
E.g. run glViewImage ~/my_images/ to display all images in ~/my_images/ directory.
A filename mask — glViewImage will display all images matching given mask, where '?' matches any char and '*' matches any number of any chars. Of course, users of bash and similar non-Windows shells can utilize shell filename expansion instead.
E.g. run glViewImage ~/my_images/*.png to display all PNG images in directory ~/my_images/. Or just run glViewImage ~/my_image.png to display only one image in file ~/my_image.png.
@<filename> — glViewImage will read image filenames from file <filename>, each line is one filename (<filename> "-" means "standard input", as usual; so you can pipe output of e.g. find program to glViewImage).
Running glViewImage with no parameters is equivalent
to running
glViewImage .
so you will view all images (that glViewImage can handle) in the current directory.
If none found, the default welcome image will be displayed.
Oh, and (as usual) all parameters described in those pages: standard options understood by my OpenGL programs and some notes about command-line options understood by my programs are available. If you will not give any parameter that forces some window size (like --geometry) then program will open a window with the same size as the first displayed image.
Resulting image format is determined by filename extension, unknown extension will result in BMP format.
Image loaded and displayed by glViewImage is internally always stored in format comfortable for OpenGL. This includes many formats, but not RGBE. It means that if you will load RGBE image to glViewImage and then you will save it (even to the RGBE format again) then you loose RGBE precision (and clamp color values above 1.0).
Also, S3TC compressed images (from DDS files) will be always decompressed, and saving them back will always make uncompressed files.
convert program from ImageMagick package must be available on $PATH for some image formats to work.
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Copyright Michalis Kamburelis. This page is considered part of documentation of my programs, and you are free to modify and further distribute it on terms of GNU General Public License. |  |