File Type Options - CGM

The File Type Options dialog is entered when you press Options in the Image Export dialog or the Send Attachment dialog. The dialog allows you to specify convert options for the currently selected image file format.

The available options depend on the file format. Here are shown the options for the CGM file format.
The CGM file format can contain different object types, including graphics, text, and images. An image saved as CGM in EasyCopy contains a single image object ("cell array").
Note, that you can read any CGM file by means of the licensable option EasyCGM, but CGM files you read are converted to image format.

Color Mode

Best Fit: Let EasyCopy determine the best color mode. This is the default. EasyCopy will choose the optimal color mode for the given image taking other current settings into account.
RGB: RGB means a 24-bit RGB image ("true color").
256: 256 means a color mapped image with 256 different colors (8 bits per pixel).
n: n Colors means an image containing n colors matching the colors of the input image as closely as possible. n is the number entered in the field labeled Colors. A color map of at least n entries is created, and a color map image is written, if this can be realized. Otherwise, a true color image is written.

Colors
Enter the number of desired colors (>2) in this field. The field is dimmed if the selected Color Mode is not n Colors. The default is the maximum possible number of colors.

Shading
This option specifies the method that applies if the output image contains fewer colors than the input image. Each output image pixel is always chosen as closely as possible to the input color of that pixel.

None: Any difference between input and output color is ignored. This may easily result in "color banding".
Error Diffusion: This is the default. Color differences are distributed to the neighboring pixels. Normally, this results in a substantially better color rendering, although at the expense of image details; the sharpness becomes slightly degraded.

Refer also to the topic Image Shading.

Scale Method

Metric: The image is scaled according to the settings in the Image Size dialog and is saved together with absolute dimensions calculated from the Resolution setting. This is the default.
Abstract: The image is scaled according to the settings in the Image Size dialog and is saved without any absolute dimensions (the image is only dimensioned in pixel units).

The image size measured in pixels is the same for these two modes.

Compression

None: Select None to get an uncompressed CGM file. This is the default.
Runlength: Select Runlength to get a compressed file.

Profile
You can specify, that the CGM file is saved with an ATA, CALS, or PIP profile. The default is ATA.

Color Map
Specifies the color map to be used, if the selected Color Mode results in the creation of a color map of exactly 256 colors.

Standard: This assigns a fixed, predefined color map to the output image. This option is useful if several images are to appear side-by-side on a device that can only display 256 colors.
Best Fit: This is the default. It means a color map giving the best representation of the input image. If the input image is color mapped, the original color map is used, as far as possible; otherwise a color map optimized for the current image is calculated.