Working with Images
MandalaMaker can import digital images and incorporate them into your mandalas. The program can also export your mandalas as images. This section provides general digital image information that will help you get the most out of these features.
Difference between Vector and Raster Images
There are two basic way to create and store graphic information on computers.
In vector graphics programs like MandalaMaker, graphics elements are objects which maintain their identity and can be moved, edited or deleted after they are created. Vector graphics are also resolution independent. This means that they can be rescaled to any size without changing the quality of the image.
In contrast, raster graphics are made up of a grid of dots or pixels. Elements added to such a image lose their identity, becoming just colored dots. A raster image has a fixed size of so many pixels wide by so many pixels high. Some graphics programs can re-scale raster images, but it does so by discarding pixels (image information) when reducing the size or inventing pixels (information) when increasing the size. Such re-scaling will always, to some extent, reduce the quality of the image.
A digital image has a number of characteristics. Among the most important are its size, resolution, compression, transparency and color space.
Digital image size is generally expressed by pixel dimensions. An image designated as 400px x 600px is 400 pixels wide and 600 pixels high. Size may also be expressed in inches, centimeters, etc, with resolution taken into account.
In vector graphics, size is just a suggestion to the program interpreting the image as to how big to make it appear.
In raster images, pixel size is an absolute, while resolution is simply a suggestion as to how visually large the image should appear.
Resolution refers to the density of pixels in an image and is generally expressed in dots per inch (DPI) or dots per centimeter.
The resolution of an image is what is referred to as metadata, meaning that it has no effect on the actual image data, only on how that information is displayed.
The size at which a raster image is displayed, expressed in inches or CMs, is dependent on resolution. If the resolution of the 400px x 600px image above were 300 DPI, the image would be 1 x 2 inches, if the resolution were 72 DPI the image would be approximately 4.1 x 8.3 inches. Note that the number of pixels has not changed and that the image at either resolution contains the same image information.
Since vector graphics are resolution independent, resolution only has meaning when the image is rendered by a raster device such as a display or printer.
Many raster image formats have the capability to compress images to some extent to shrink file size. Compression can be either lossless or lossy. Lossless compression preserves all image information in the compressed file, while lossy compression discards some information during compression. A good lossy compression method limits its impact on image quality.
Vector graphics files do no have use compression internally, but can be compressed with any file compression utility.
Some raster image formats have an opaque background. In such an image, if there is no image information in an area of the image frame, those areas will appear white. Other formats allow for a transparent background, where areas of the image frame without image information will allow whatever is behind the image to show through.
Vector graphics formats support transparency.
MandalaMaker allows you to create "translucent" paints that allow background objects to show through. These effects will still be visible whether the output format supports transparency or not. However, if the mandala background is translucent, it will export as opaque unless the target format supports transparency.
Image formats vary in their ability to encode colors in different color spaces. For a discussion of color spaces, see the Working with Paints section.
There are numerous digital image formats, each with different capabilities regarding the characteristics discussed above. MandalaMaker can import four different raster image types or formats and can export one vector format and three raster formats.
SVG, or Scalable Vector Graphics, is a vector image format developed by the World Wide Web Consortium as an open standard. SVG files are based on XML, so they are plain text files that can be read and edited with a simple text editor, viewed in most modern web browsers, or viewed and edited in many graphics programs. SVG files can also be used to drive many cutting and/or engraving devices. MandalaMaker can export SVG images, with the limitation that images imported using the Image Effect Palette are not exported. Text elements in a MandalaMaker drawing are converted to shapes when exported to SVG. SVG import may be supported in the future.
JPEG is short for Joint Photographic Experts Group. As the name suggests, this image format was designed to store digital photographs. It is a high quality format for continuous-tone images. JPEG uses lossy compression, however the compression algorithm is designed to have minimal impact on the visual quality of the image. JPEG provides a range of quality settings that allow a custom tradeoff between file size and quality. JPEG images are opaque, and the format can support a range of color spaces, including RGB and CMYK. JPEG images can be created at arbitrary resolutions. MandalaMaker can both import and export JPEG images. When exporting JPEGs, MandalaMaker always uses the maximum quality setting. Unless you are targeting the web or need image transparency, JPEG is the recommended export format.
PNG stands for Portable Network Graphics. This format, which supports lossless compression and transparency, has become the modern standard for web images. As a format designed for the screen display, PNG is limited to RGB colors, but supports arbitrary resolutions. MandalaMaker can import and export PNG images.
GIF, which stands for Graphics Interchange Format, was created by CompuServe (when the internet was young) as a way of sharing images. The format uses a palette-based compression scheme limited to 256 colors, making it ill suited for photographic images. It's compression is technically lossless, but the limited color palette will result in dithering of images with more than 256 colors. GIF does support transparency but is limited to 72 DPI resolution. MandalaMaker can import and export simple (non-animated) GIFs.
BMP, short for bitmap, is a simple image format that supports transparency, arbitrary resolutions, and optional compression. MandalaMaker can import BMP files, but does not export to the format.
As discussed above, MandalaMaker can import JPEG, PNG, GIF or BMP images.
When you add an image to your mandala, the program will require you to set the size parameter of your mandala via the Export Settings dialog. This is because, while the Shape and Text elements of your mandala are resolution independent and will print and export smoothly at any size, image elements have a certain number of pixels to work with. Fixing the size of your mandala allows MandalaMaker can ensure maximum quality of the image elements in output.
When viewing your imported image in Image Edit mode, the size of the Canvas represents the full size of your mandala and the image will be sized proportionally on it. With the Image Scale at 100%, one pixel of the imported image will fill one pixel when exported, yielding maximum image quality.
When you increase the Image Scale, MandalaMaker interpolates (invents) new pixels to fill the larger space. When you reduce the Scale, MandalaMaker throws away the extra pixels and does it's best to maintain the image's integrity. While rescaling works quite well in practice, you should be aware that some amount of image quality will be lost. You can zoom in on your mandala in Preview mode to check that the quality will be acceptable for your purposes.
A Note About Copyright
Be aware that the creator of an image has copyright to that image. If you import images found on the web or from other sources and then distribute or sell the resulting mandala, you may be violating copyright laws. Using parts of copyright images (such as in the Tile Effect) may fall under "fair use," but when in doubt, check with the copyright holder or don't use the image.
Mandalas can be exported at arbitrary sizes (though always square), in one vector format and in three raster formats with four possible resolutions. If your mandala does not contain images, these choices can be made at any time before export. As discussed above in the Import section, when you add an image to your mandala you will need to make this decision before you can add the image.
MandalaMaker can export in SVG, JPEG, PNG or GIF formats. Choose a file format that suits your intended use. See the discussion of formats above.
MandalaMaker allows you to display the size parameter in units of pixels, inches or centimeters. Changing the display unit does not change the size of your exported file.
Choose a resolution suited to your intended use. For printed images 300 DPI is generally high enough. Use 600 DPI where extra high quality is required. 150 DPI is fine for web images. The resolution is irrelevant for SVG export.
About Meta Information
An image file typically contains more information than just the visible image. So called meta information in the file may include the resolution, color space, camera specs and settings (in the case of photos), timestamps, GPS information and much more. There are several "flavors" of meta information and different image viewing and editing applications may read or write in different flavors. MandalaMaker writes resolution information to it's export files, but depending on the program that is reading that file, that information may or may not be visible. Be aware that you can easily set or change the resolution meta data in many image handling applications. If you do this without resampling, your actual image information will remain unchanged.