ToyViewer can read and display image files in following formats: TIFF, GIF, BMP, PNG, JPG, BIE (JBIG), PCX, PCD, PICT, PNM (PPM, PBM, or PGM), XBM, MAG, SUN Rasterfile, JPEG2000 (JP2, JPC, J2K), and other formats supported by OS X. Displayed images can be saved in following formats: TIFF, PDF, GIF, BMP, PNG, JPG, JPEG2000, BIE (JBIG), PNM, or XBM.
ToyViewer can attach a custom icon to any file as well as newly saved image file.
ToyViewer can read and write GIF or PNG files with transparent color, and also can read and write interlaced (progressive) GIF, PNG, or JPG files.
ToyViewer can scan (auto-display) image files in a folder.
You can also display images in full-screen size.
Displayed images can be scaled (enlarge/shrink).
You can rotate, flip, or clip images.
ToyViewer has ability to adjust brightness, contrast, color tone of images, and has some typical operations to images, such as enhancement, embossing, and so on.
You can replace specified color with other color or transparent color.
Full color images can be reduced into 256, 64, or 8 colors. Also, each color value of images can be cut down to 4-, 2-, or 1-bit.
ToyViewer can make images monochrome (8-bit gray, 2-bit gray, or bi-level). Images can be printed.
You can set ToyViewer to display any image format if there is a filter program to PPM format.
ToyViewer provides image-conversion filter services for other applications.
You can add comments to images (comments are written into only GIF, PNG, JPG, or PNM formats).
You can make Aqua-button-like images.