Logo Design: final files

Is, in principle, a very flexible format that can be lossless or lossy. The details of the image storage algorithm are included as part of the file. In practice, TIFF is used almost exclusively as a lossless image storage format that uses no compression at all.

Most graphics programs that use TIFF do not compression. Consequently, file sizes are quite big. (Sometimes a lossless compression algorithm called LZW is used, but it is not universally supported.).

This is usually the best quality output from a digital camera. Digital cameras often offer around three JPG quality settings plus TIFF. Since JPG always means at least some loss of quality, TIFF means better quality. However, the file size is huge compared to even the best JPG setting, and the advantages may not be noticeable.

Creates a table of up to 256 colors from a pool of 16 million. If the image has fewer than 256 colors, GIF can render the image exactly. When the image contains many colors, software that creates the GIF uses any of several algorithms to approximate the colors in the image with the limited palette of 256 colors available.

Better algorithms search the image to find an optimum set of 256 colors. Sometimes GIF uses the nearest color to represent each pixel, and sometimes it uses "error diffusion" to adjust the color of nearby pixels to correct for the error in each pixel.

If your image has fewer than 256 colors and contains large areas of uniform color, GIF is your choice. The files will be small yet perfect.

At moderate compression levels of photographic images, it is very difficult for the eye to discern any difference from the original, even at extreme magnification. Compression factors of more than 20 are often quite acceptable. Better graphics programs, such as Paint Shop Pro and Photoshop, allow you to view the image quality and file size as a function of compression level, so that you can conveniently choose the balance between quality and file size.

This is the format of choice for nearly all photographs on the web. You can achieve excellent quality even at rather high compression settings. I also use JPG as the ultimate format for all my digital photographs. If I edit a photo, I will use my software's proprietary format until finished, and then save the result as a JPG.

Digital cameras save in a JPG format by default. Switching to TIFF or RAW improves quality in principle, but the difference is difficult to see. Shooting in TIFF has two disadvantages compared to JPG: fewer photos per memory card, and a longer wait between photographs as the image transfers to the card. I rarely shoot in TIFF mode.

A bitmap file is a raster- (or pixel-) based format that only supports the RGB color space and bit depths of 1, 4, 8, or 24 bits per channel. These attributes make bitmap images unsuitable for use in a high-end print production workflow.

Even though bitmap images are in the RGB color space, they are not supported by any Web browsers or Web coding languages. Therefore, they are not suitable for use as images in a Web application.

You would be able to use such a graphic in an HTML export from InDesign by having the automatic conversion to a GIF or JPEG file occur. Bitmap images are best used for their intended purpose, as a system support on a PC Windows-based computer. Do not use the placement of a bitmap image when designing for a high-end print production job.

PSD

Are proprietary formats used by graphics programs. Photoshop's files have the PSD extension, while Paint Shop Pro files use PSP. These are the preferred working formats as you edit images in the software, because only the proprietary formats retain all the editing power of the programs.

These packages use layers, for example, to build complex images, and layer information may be lost in the nonproprietary formats such as TIFF and JPG.

EPS

Language file format can contain both vector and bitmap graphics and is supported by virtually all graphic, illustration, and page-layout programs. The EPS format is used to transfer PostScript language artwork between applications. EPS can be easily exported from most graphics and desktop publishing applications. This format is used mostly for print.

EPS is typically used for elements to be included in a page layout or PDF document. Because PDF files can be designed for onscreen display as well as print, EPS supports the RGB color mode in addition to the CMYK and Grayscale modes. EPS files cannot be displayed by Web browsers (although they can be incorporated into PDF files, which can be shown through a browser plug-in).

One of the greatest advantages of EPS as a file format is the capability of including both raster and vector data and artwork.