Changing Image Size

Tonights session will cover changing the size of an image. Anyone who builds web pages and/or creates tutorials, uses this method to reduce the size of their images so their images do not take up so much precious disk space when you only have 20mb of server space to display your compleate website. Having said this, we can also enlarge an image.

Open PSP, go to File || Open and go to where you unzipped and saved hummingbird.psp.

As you view hummingbird.psp, you will notice the width and height are in pixel sizes. We can make this a smaller graphic that would be better suited for a Web page (not that this image is that large to start with). This is not the type of graphic that needs to be so large to view.

To see what the width and height are of this image, look at the bottom right hand corner of the status bar.

We will resize this image to a width of 200 pixels.

This image has been modified
for the purpose of this tutorial.

Click on Image || Resize... or Shift S to open the Resize dialog box.

Before you do anything, let's take a look at the various sections of the Resize dialog box.

Pixel Size: By choosing this option, you can set your image to a definite size by either width or height.

Percentage of Original: By choosing this option, you can resize your image by a percentage instead of working by pixels.

Actual / Print Size: This is for resizing an image for printing rather than onscreen viewing.
- Width and Height are self explanatory.
- The drop-down menu on the right of W and H is for if you want to work in cm, inches.
- Resolution is for your printer resolution.
- The drop-down menu on the right of Resolution is to set it to be pixels / cm or pixels / inches.

Resize Type: You have four (4) types to choose from:
- Smart Resize: I haven't worked out where one would use this one. I did try it out on a dialog box once (reducing the size) and it gave me a lossy type quality.
- Bilinear resample: This is good for reducing the size of your image. If using this on dialog boxes, use Sharpen once then save as a gif. On other types of images, use your own judgement.
- Bicubic resample: This is good for enlarging the size of your image.
- Pixel resize: I have never used this one before so I have no idea what for or why one would use it. Maybe it is used in conjuction with the Resolution option. I do not know.

Resize All Layers: With this option checked, the complete image will be affected by the resize method applied. If it is unchecked, then only the layer you are working on will be resized.

Maintain aspect: With this option checked, when you change the width (for example), the height will change so the image will not be distorted when you apply the resize. If it is unchecked, and you only change the Height, then the width will not change.

ratio of ... to 1: Where the image says 1.2 (this may differ due to the version you are using or if you have changed it at all), I usually leave this alone.

Smart Resize: Reduced.

All you can do is compare it to the original image and make your own decision.

Bilinear Resample: Reduced.

All you can do is compare it to the original image and make your own decision.

Bicubic Resample: Reduced.

All you can do is compare it to the original image and make your own decision.

Pixel Resize: Reduced.

As you can see, this is not a good option for this type of image. The loss of quality is very obvious.

Smart Resize: Enlarged.

All you can do is compare it to the original image and make your own decision.

Bilinear Resample: Enlarged.

All you can do is compare it to the original image and make your own decision.

Bicubic Resample: Enlarged.

As you can see, the detail is quite reasonable.

Pixel Resize: Enlarged.

As you can see the quality of this image is not so good.

These images have been modified
for the purpose of this tutorial.

To see what they truly look like after you resize them save your resized image with a new name:

Click on File || Save As... (F12)
In the File name box type "hummingbirdsmart" (The smart refers to the resize method you used).
Click on the arrow in the Save as type box to choose JPEG.
Click on Save.

The best way to work out what resize method to use is to try it out on different types of images: Line art, cartoon art, greyscale, etc.

Once you have found the best method for your image, you will know then what to do next time.

Next week, you can get your hands dirty as we learn how to Create New Images by Making Buttons.