Saving Your Work


Saving your work may seem like a straightforward and simple thing but there are some considerations that will have an effect on the quality of your images and hard drive space.

When I decided to write this tutorial, the research started to overwhelm me. 

Nobody could give me a straight answer.

There were too many vested interests and personal axes to grind.  The orientation of the answers depended on the software in which the users processed their photos.

The number of file formats is incredible. 

  • Some are specific to a piece of software.
  • Some are specific to an application.
  • Some are specific to a camera manufacturer and unreadable by any other application. 

If you have Paint Shop Pro; Photoshop, or Photoshop Elements, you have more than a good chance that you will be able to read the majority of the file formats, and to a lesser extent to write to them. 

But some formats are not interchangeable even between these big three!

File Formats



There are two main file types that your digital camera may use. First (and most common for compacts and hybrid cameras) is JPEG or JPG or JPEG2000.  Second (and most common for top end DSLRs) is a "dialect" of RAW (since all DSLRs speak their own language).

The RAW format records all the information that the lens sees.

When you take your picture, the image is written in code to the memory of the camera and then to the memory card. Each of the pixels provides information and there are different methods of reading the camera sensor, and different types of sensors, and a lot of information to be processed. It is these different coding processes which give rise to the different file types.

The RAW format records all the information that the lens sees. Like the film in an analogue camera it has the greater flexibility to be processed by you, and just as there used to be a large range of films, each digital camera has its own “dialect” of RAW.

The “dialect” is the variation on the coding language. This is the first and main problem for RAW; software support is not and will not always be available.

Just to give you a simple example, Paint Shop Pro X3 will read the RAW files from my Sony DSLR but Photo Shop Elements 7 will not. The RAW converter software from Sony will read the files from my Sony but not from other manufacturers. So camera to Paint Shop Pro X3 is a simple one-stage operation, but camera to Elements requires an intermediate stage of file conversion.

This is just a feature of the “dialect” of the RAW file, ie just a slight difference in the way in which the picture file was written to the memory card.

The JPEG is the product of in-camera processing.  Whilst there are fewer dialectal problems, your camera will have carried out some processing of the image, especially if you've chosen a scene setting such as "sunset" or “snow”. 

When your image gets onto your PC or Mac, any changes that you make to the image will add to the other inherent JPEG problem.  To save space, JPEG applies some clever Mathematical algorithms (calculations).

By looking at the neighbouring pixels it works out how space might be saved by losing a pixel or two.  Every time you save a JPEG, this calculation and pixel loss occurs.

Let’s look at a picture which has been compressed to save space on the Hard Drive.

Here’s the original uncompressed file

saving your work original


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Nice shot, Terry!
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And here’s the file which has been compressed by a factor of 99 times


saving your work compressed


Ouch!

The changes within the image are painfully obvious, but what about compression settings which are less than 99; some of these are not so obvious.

So we need to look at slightly magnified portions of the image at different compression factors.


saving your work master saving your work compression 10
Original Image - no compression Compression 10
saving your work compression 20 saving your work compression 50
Compression 20 Compression 50
saving your work compression 60 saving your work compression 70
Compression 60 Compression 70
saving your work Compression 80 saving your work compression 90
Compression 80 Compression 90
saving your work compression 99 After about a compression factor of 20 the image shows loss of detail, loss of contrast, and eventually loss of colour.
Compression 99


So how do you prevent degradation of the image?


Image Degradation


There is much debate as to the best way of addressing this problem.  The consensus, from mainly professional users, is roughly as follows.

  • Convert your images to one of the interchangeable formats such as TIFF as soon as possible.  The downside of this is the large file size that TIFF produces.

  • Work in progress should be in one of the standard formats from Paint Shop Pro; Photoshop, or Photoshop Elements such as PSPIMAGE; PSD.  Don’t sharpen or downsize the image until the very last step.

  • Submit work for printing as JPEG or another recognized format, but don't re-edit it in this format.  Most printers require work submitted at 200 or 300 pixels per inch.

  • Work for Net use should be in an appropriate format, such as GIF, but again don't re-edit in this format, work from your PaintShopPro; Photoshop, or Elements format.  Most internet sites require work at 72 or 96 pixels per inch.


The big caveat is the algorithm which is used for compression.  Again there is much discussion about this.  The general consensus is to use LZW since this gives the least interference and loss.


Image Compression


It would seem that you could get away with compression of x10, but what would you save?

Remember, once you’ve compressed the image, you’ve lost the data for ever and you can never, ever get it back again.


Image Compression File Size
600 ppi original 786,425
X10 236,688
X20 155,486
X50 52,547
X60 43,710
X70 37,876
X80 33,477
X90 29,789
X99 27,157


Saving Your Work in Paint Shop Pro


So where do you find the settings to compress your image in Paint Shop Pro?

saving your work save as


Select the option button and the choices menu will appear, so that you can choose your compression value.


saving your work save options


If your reason for compression is uploading to the internet, it might be worth considering an alternative method such as Picasa.

What happens if your continue to work on a file and continue to set the compression value at a high value;  ie you don't reset the compression option value in the "Save" dialogue.

Let's look at the image after 10 successive edits and saves.  At compression value 10 the degradation is minimal, but the sharpness of the image is suffering slightly, so what does repeated saving do?


saving your work compression 10 Compression factor of 10.  

The first save of the original image.
saving your work Compression factor of 10;  the tenth save of the original image each time at a compression value of 10.

The image is lacking sharpness.
saving your work Compression factor of 20;  the tenth save of the original image each time at a compression value of 10.

The contrast is failing.
saving your work Compression factor of 50;  the tenth save of the original image each time at a compression value of 10.

The image has lost sharpness, definition and the contrast is going.

What lessons have we learned?

Firstly and most importantly, the ultimate end-usage of the image dictates the file type under which it will be stored; the image quality in terms of pixels per inch is lower for web use than for paper publication; some formats such as GIF store the image in a lower quality.

Secondly, the format of the image in the camera can determine the extent to which it can be manipulated.  Images which may be processed many times or in many stages are not best taken as JPEGs, nor should they be compressed until the final stage.

Thirdly, the intermediate stages of image processing are best stored in recognized and interchangeable formats such as TIFF or the internal format of the processing software such as PSD or PSPIMAGE.

Fourthly, some formats are not interchangeable between process software.




Page Links

File Formats

Image Degradation

Image Compression

Saving In Paint Shop Pro









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