Hi all! This weeks lecture was about digital image management. I learnt about the different image formats you can store your images as, Print vs. screen and also image metadata.
I’m sure that many of you already know about the screen capture feature on your computer, but if not it’s a useful tool. It is a quick way of creating internet-friendly copies of images with a larger resolution. Most of you will know that you can use the snipping tool on your PC to do this. If you are using a Mac you can use grab. For this you simply press the keys CTRL + Shift + 4.
Image file formats are a way of organizing and storing your digital images. These files are made up of pixel or vector data or both. Bitmaps are a dot matrix data structure that represent a rectangular grid of pixels or points of colour and are viewable on anything you can look at images and I don’t just mean things in the digital world, who could forget about paper?! They map the image to bits which have values of zeros or ones hence the name bitmap. A bitmap is also known as a raster image and they can be stored in many different image file formats.
An intro to compression types
I mentioned in a previous post about saving a file in a compressed or uncompressed file format. If you do want to compress a file, Lossless compression allows you to compress the image without loosing any of the quality. If you wish to preserve the quality then this is the best option to go with however uploading a file like this to the internet could take ages!
Lossy compression is another option you can choose when you want to compress your files. This reduces the file size even more as it discards invisible information to the human eye. Most of the time you can vary the level of compression you wish to choose but if you compress your file too much, the image will become very distorted from the original.
There are so many image formats!
Here is a list of the different types of image formats with a little explanation beside each to help you understand the difference between them.
- PSD – This is a Photoshop file. When you edit your image in Photoshop, this is the first option to save your file as. This file type will always need to be supported by the version of Photoshop it was edited with.
- TIFF – Or its full name, tagged image file format, is a format for storing images that many graphic artists use. Again it is under the control of Adobe. This is an uncompressed file type.
- DNG – This is an open lossless RAW image format by Adobe. It is used for storing digital images. It saves the photo with a greater bit-depth and also a wide colour scope.
- GIF – The graphics interchange format is a bitmap image format. It allows animated images or just still images to be stored. Many of you will know what GIFs are from sites such as Reddit. It is suitable for storing things like logos that have solid areas of colour. Websites such as GifMaker allow you to create your own GIFs.
- PNG – This is again a bitmap image format that uses lossless data compression. This is the most used lossless format on the internet and does not require a patent license.
- JPEG – This is a compressed image file type and is usually used when you make edits to your pictures and then save. just remember the more you edit and save, the more you decrease the image quality. It can be a valuable way to store images you want to upload as it can create a very small file size.
When you want to upload images to the internet there are many different sites that allow you to do this. One of the most popular sites, which a lot of you probably know about, is Imgur.
Exif or exchangeable image file format is a standard that specifies the formats for images, sounds and ancillary tags used by your digital camera or your smartphone. It allows tags to be added to JPEG files, TIFF files and also WAV files. So when you take photos with the camera on your phone and it tags where it was taken, it can be found by anyone that looks up this tag. If you don’t want your image to be seen you can easily turn location services off on your phone.
That concludes this weeks post on digital image management. Remember to follow my blog and stay tuned for next weeks post on Social Media Tools!
- Screenshot tool – http://computertutorflorida.com/2011/10/windows-7-built-in-screenshot-tool/
- Bitmaps – http://matter.sawkmonkey.com/raytracer/bitmap.html
- Imgur – http://embed.ly/embed/features/provider/imgur