Digital Image Formats - JPEG, GIF, RAW ..
What Do All These Mean?
By: Mike Singh

We spend hours and hours, taking the best photographs we can, and when we're done - we apply special techniques to them with a special editing software to enhance what we've originally seen. When we are done, we try and save them in the correct format to preserve the image in the best way possible, but most people have no idea what the differences are.

The three main files a digital camera uses to store its digital images are JPEG, TIFF, and RAW formats. We need to understand what these digital image formats are and their properties - only then will we be able to get a high quality photograph.

The first format, and the one used in graphic design and photography quite often, is JPEG - a commonly used standard method of compression of images. In fact, the majority of photographers use this as their primary image mode. One of the main reasons is because it can be used right out of the camera with no editing, as it is considered a high-quality first use image. It also transfers easily across the Internet, and as email attachments. Plus it is fastest writer from the camera memory buffer to the memory card storage.

On the other side, it is not as sharp out of the camera as TIFF or RAW modes, and every time the JPEG is manipulated more than once or twice, it will eventually become unusable. But more than any of this, every time the JPEG image is modified and resaved, it will lose more data.

PEG stands for "Joint Photographic Experts Group", named after the joint committee which created it in 1986. The JPEG (file extensions are .jpg, along with .jpeg, .jfif, jpg., .JPG, and .JPE) format provides for lossy compression of images, which means that when data is compressed, and then decompressed, the data that is decompressed may be different than the original. Yet, it is sufficient to be useful in some way or another.

JPEG/JFIF is the format that is used when photographs are stored and transmitted on the Internet. It is preferably over GIF, which is limited to 256 colors that are not enough for colored photographs, or PNG, what produces larger image files.

But then, just as many photographers use TIFF as their primary usage. The TIFF is a file format used for storing images such as line art and photographs, developed by Aldus, now Adobe Systems, and Microsoft. A popular format for high color depth images, it is supported by many image-manipulation programs such as Pagemaker, QuarkXPress, Adobe InDesign, PhotoShop, Paint Shop Pro, etc. It is extremely high in its image quality, with excellent compatibility with the publishing companies.

Tiff can be modified and resaved, with the images being used an endless number of times without throwing away any image data. Plus the image is extremely usable, as it does not require software post-processing during or after its download from the camera. It is a flexible and adaptable , with an advantage of no picture loss, which makes it acceptable to the publishing industry.

Compared to the RAW format, it uses less storage space, and is suitable for changes from any photo-editing software. A big disadvantage is its very large file size, still choking small e-mail boxes. During photography shoots, memory cards are needed if using TIFF images, but more pictures can be taken with the same amount of memory space.

The RAW mode is a picture format where the camera has made absolutely no changes; the files are not yet processed or ready to use with an editor, etc. Not a whole lot of professionals use this mode, other than camera purists, or weird website article writers. In order for it to be manipulated, the image needs to be processed and converted to an RGB format that is either TIFF or JPEG. This means that each and every pixel that was captured by the camera is now on the image.

You can now download this image on your computer for processing. Its advantages are that a huge amount of control over the final look of the image is yours. Additionally, all original details stays in the image for any and all future processing needs.

However, when you do so you will notice that this is a very large image, probably a few MBs. This means that you will need a very large storage area or memory space if you are going to shoot images in RAW format. Your advantage is that you can sharpen, size, or crop the picture without losing any picture quality.

But your disadvantage is the file size. You cannot transmit it easily because it needs high bandwidth connections. Also, you can shoot very few photographs if you select the RAW mode. After that, you have to change the memory card or make space by erasing a few photographs. Also, this mode is generally not accepted by the publishing industry because it produces a 12-bit image. The photographer needs to modify it using photo-editing software before submitting it for publication.

Overall, if a photographer wants to keep all the original image data that was recorded, the image must be stored in RAW format. It is the closest thing that we will be able to see in a film negative or a transparency that the digital camera can make.

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