Thursday, 27 March 2014
File Compression
Now I am at the stage now where I am finalizing the Photoshop and Illustrator designs. I now have to think of the different files types that are out there. This is so that when I compress my final pieces I will need to choose which of the file type I will use.
Before I go onto the different types of files, some of these file types are either known as a Lossy or a Lossless compression. Lossy is a type of compression which works very differently. What it does is that it eliminates unnecessary bits of information which tailors the file so that it is smaller. It is used a lot for reducing the file size of bitmap pictures, which tend to be fairly bulky. However, once you have the done a lossy compression you can not get the original file back once compressed. So if something needs to be reproduced then this sort of compression is not suitable.
Lossless on the other hand, is a compression is based on the idea of breaking a file into smaller form of transmission or storage and then putting them back together on the other end so it can be used again. Meaning that is can recreates the original file. However, sometimes if there are larger parts of a picture, for example a blue sky most of the individual pixels which are a little different. Then the picture is rewritten then one colour would be picked one colour of blue that could be used for every pixel. So if the compression scheme works well, you wont notice the change, but the file size will be significantly reduced.
There are quite a few different types of file types. The first is JPG or JPEG. It stands for Joint Photographic Experts Group. It is the most common file format for digital cameras and widely used for photos and other graphics used on websites. So when a file is saved as a JPG they use lossy compression, meaning image quality is lost as the file decreases in size. JPG files allow some degree of file size reduction without losing too much image quality, unlike GIF files. However, when a JPG image file gets really low the image becomes really muddy; meaning that you have to choose between quality and file size.
Another file type is GIF. This is known as Graphics Interchange Format. It is a an 8-bit colour file, meaning that it is limited to a palette of 256 colours which are picked from the RGB colour model. It is counted as a lossless compression. However, because it is converting to a 8-bit colour image this can radically alter an image for the worse, or create an interesting effect. Because of the non-lossy format, GIF can also be used to keep tight lines on typography and geometric shapes, making it better suited to vector graphic files such as Adobe Illustrator. This means that it is not that ideal for modern photography nor image storage, as the smaller the size of the file the limited colour tables, GIF images can be smaller then JGP files.
PNG is another file type, it stands for Portable Network Graphics. It was developed as an alternative to GIFs. They are non-loosy files, compressing photographic image without degrading image quality as they support 24-bit colour RGB like a JPG. PNG tends to be the biggest of three file types and isn't supported by some browsers. This makes this browser is an excellent file type for internet graphics, as it supports transparency in browsers with a elegance that GIF does not possess. However, it tends to be the biggest of the file types without degrading image quality.
BMP is another file type, it is short for Bitmap. It is commonly ued for raster graphic format for saving image files. It is the most common format on the Windows Platform and now has been recognized by many programs on both Macs and PCs. It stores colour data for each pixel in the image without any compression. This method of storing image information allows for crisp, high-quality graphics, however, it produces large file sizes. JPEG and GIF formats are also bitmaps, however they use image compression algorithms that can be significantly decrease their file size. Which is the reason why BMP images are often used for printable images.
Seeming that I am going to be compressing my final designs for the assignment, in class we did a little experiment with different file types. This then allowed us to see which ones looked the best, so we did not just jump straight in a compressed it; then ended up not being happy with the results. We did this for both Photoshop files (Photograph) and Illustrator files (Logo). Here were the results.
Before I go onto the different types of files, some of these file types are either known as a Lossy or a Lossless compression. Lossy is a type of compression which works very differently. What it does is that it eliminates unnecessary bits of information which tailors the file so that it is smaller. It is used a lot for reducing the file size of bitmap pictures, which tend to be fairly bulky. However, once you have the done a lossy compression you can not get the original file back once compressed. So if something needs to be reproduced then this sort of compression is not suitable.
Lossless on the other hand, is a compression is based on the idea of breaking a file into smaller form of transmission or storage and then putting them back together on the other end so it can be used again. Meaning that is can recreates the original file. However, sometimes if there are larger parts of a picture, for example a blue sky most of the individual pixels which are a little different. Then the picture is rewritten then one colour would be picked one colour of blue that could be used for every pixel. So if the compression scheme works well, you wont notice the change, but the file size will be significantly reduced.
There are quite a few different types of file types. The first is JPG or JPEG. It stands for Joint Photographic Experts Group. It is the most common file format for digital cameras and widely used for photos and other graphics used on websites. So when a file is saved as a JPG they use lossy compression, meaning image quality is lost as the file decreases in size. JPG files allow some degree of file size reduction without losing too much image quality, unlike GIF files. However, when a JPG image file gets really low the image becomes really muddy; meaning that you have to choose between quality and file size.
Another file type is GIF. This is known as Graphics Interchange Format. It is a an 8-bit colour file, meaning that it is limited to a palette of 256 colours which are picked from the RGB colour model. It is counted as a lossless compression. However, because it is converting to a 8-bit colour image this can radically alter an image for the worse, or create an interesting effect. Because of the non-lossy format, GIF can also be used to keep tight lines on typography and geometric shapes, making it better suited to vector graphic files such as Adobe Illustrator. This means that it is not that ideal for modern photography nor image storage, as the smaller the size of the file the limited colour tables, GIF images can be smaller then JGP files.
PNG is another file type, it stands for Portable Network Graphics. It was developed as an alternative to GIFs. They are non-loosy files, compressing photographic image without degrading image quality as they support 24-bit colour RGB like a JPG. PNG tends to be the biggest of three file types and isn't supported by some browsers. This makes this browser is an excellent file type for internet graphics, as it supports transparency in browsers with a elegance that GIF does not possess. However, it tends to be the biggest of the file types without degrading image quality.
BMP is another file type, it is short for Bitmap. It is commonly ued for raster graphic format for saving image files. It is the most common format on the Windows Platform and now has been recognized by many programs on both Macs and PCs. It stores colour data for each pixel in the image without any compression. This method of storing image information allows for crisp, high-quality graphics, however, it produces large file sizes. JPEG and GIF formats are also bitmaps, however they use image compression algorithms that can be significantly decrease their file size. Which is the reason why BMP images are often used for printable images.
Seeming that I am going to be compressing my final designs for the assignment, in class we did a little experiment with different file types. This then allowed us to see which ones looked the best, so we did not just jump straight in a compressed it; then ended up not being happy with the results. We did this for both Photoshop files (Photograph) and Illustrator files (Logo). Here were the results.
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| Results of the Photograph quality in Photoshop |
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| Results of the Photograph quality in Illustrator |
- Lossy and Lossless Compression [Online] Available at: <http://computer.howstuffworks.com/file-compression3.htm> [Accessed 27th March 2014]
- JPEG Files [Online] Available at: <http://graphicdesign.about.com/od/Definitions/g/Jpg-Files.htm> [Accessed 27th March 2014]
- GIF Files [Online] Available at: <http://www.howtogeek.com/howto/30941/whats-the-difference-between-jpg-png-and-gif/> [Accessed 27th March 2014]
- PNG Files [Online] Available at: <http://www.howtogeek.com/howto/30941/whats-the-difference-between-jpg-png-and-gif/> [Accessed 27th March 2014]
- BMP Files [Online] Available at: <http://www.techterms.com/definition/bmp> [Accessed 27th March 2014]
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