GlossaryRAW image

EOS DIGITAL camera RAW images are recorded in an uncompressed 14bit or 12bit format.

Because RAW images are special images in an undeveloped status, you need software with development processing functions such as DPP in order to view them. The advantage of the undeveloped RAW images is that you can make a variety of adjustments to RAW images with almost no deterioration of the image.

* “RAW” meaning “in a natural condition” or “not processed or refined”.

JPEG image

The most ordinary image in non-reversible compressed 8bit format. The advantage of this is that by saving at a high compression rate, the file size can be small, even for image data that has a high pixel count. Because during saving and compression part of the data is thinned out to make the file size small, every time you edit or save, the image deteriorates.

With DPP, even if you repeat editing/saving, only the recipe data is modified, and no overwriting or compression occurs so the original image data does not deteriorate.

* JPEG is an abbreviation of “Joint Photographic Experts Group”.

TIFF image

Bitmap-format image recorded in a 8bit/16bit uncompressed format. Because TIFF images are in uncompressed format, they are suitable for saving an image while maintaining the original high image quality.

* TIFF is an abbreviation of “Tagged Image File Format”.

Recipe

The “Image processing conditions information” for RAW images that can be edited in DPP is called a “recipe”.

Further, in DPP, you can perform image editing on JPEG and TIFF images that use “recipes” as with RAW images.

bit number

Binary unit of information volume in the color of an image. The number shows the number of bits per pixel.

The larger the number of bits, the more the color numbers and the gradation becomes smoother. A one-bit image is a black-and-white image.

Color Management System (Color Matching)

Digital cameras that shoot images, monitors that display images, and printers that print images each have a different way of creating color. For this reason, there may be a difference between the color of an image when viewed on a monitor and when printed.

A color management system is a system for managing color in order to bring these colors closer together. With DPP, you can more closely match color between different devices using ICC profiles between different devices.

ICC profiles

ICC profiles are files containing color information such as color characteristics and color space for various devices, set by the ICC (International Color Consortium). Most devices such as the monitor we use to view images or the printer we use to print images can be managed (color management) using these ICC profiles and the color between different devices can be more closely matched.

DPP has color management that uses these ICC profiles.

Tone Curve

A tone curve shows values before adjustment (input) as the horizontal axis on a graph, and the values after adjustment (output) as the vertical axis. Since the values of before adjustment and after adjustment are the same before any adjustment is made, the tone curve displays as a straight line from bottom left to top right, and by changing this tone curve, you can adjust in detail the image’s brightness, contrast and color. The more you go right on the horizontal axis, the more the plus value it becomes, and the higher you go on the vertical axis, the more the plus value it becomes.