Resizing Images

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Digital cameras are producing ever bigger pictures, both physically and in file size. This means that without a bit of attention they can appear way too big on a webpage, and take a long while to appear, especially for modem users.

To get round this, they need to be both resized and compressed. This can often be done with the software than comes with the camera, but there are so many variations it's difficult to give instructions. So here are methods using free software for Linux, Macintosh (OSX) and Windows.

A good size for web image uploads is 640 pixels wide with a max height of perhaps 480. You might want to make them as small as 400 wide to reduce the chance of somebody stealing them for print publication without your permission.

.jpg is the obvious first choice for file format with compress set at about 7 (70%) for a good compromise between file size an quality. Using an even lower figure would reduce the chance of your images being stolen.

Linux

Using Gimp

source: http://www.gimp.org/tutorials/Lite_Quickies/#scale

The first thing that you might notice is that The GIMP opens the image at a logical size for viewing. So, if your image is really big, it will display it zoomed out until it fits nicely. You can tell if The GIMP has done this by the percentage number in the title bar (you can click on the little screenshot to see the full view of the screenshot). Just because it looks right in this "View" doesn't mean anything!

The other thing to look at in the titlebar is the mode. If it says RGB in the title bar, you are fine. If it says Indexed or grayscale there, you should read the change the mode guide.

Image entry in the menu and the-sub menu from the screenshot should reveal itself. Click on "Scale Image...". Whenever you click an option from the menu that has ... behind it, expect another dialog. This time, you should get the "Scale Image Dialog".

Scale1.png

If you have a desired width, put it in the dialog at the top where it says "New Width". If you don't have such a number in mind, you can use The GIMP's templates (e.g. 640x480 pxls) or use The GIMP's default image size, which is 256 pixels.

Perhaps you want your image to look more like a 4x6 inch photo on most image rendering web browsers. Simply switch the units to "inches" and put 4 inches in the height box (opting for smaller than 4x6 rather than bigger).

Scale2.png

Let The GIMP choose the other dimension length for you. Meaning, it will take more image knowledge to change both width and height and have it look correct. So only change one and let The GIMP change the rest. To change the other length see the crop guide.

Macintosh OSX

Most Macs running OSX come with a copy of iPhoto, and if you use this already then you need no advice, other than to select Share ->Export and set the scale of the images to no more than 500 pixels width (for landscape format pictures) or 400 pixels width (for portrait format pictures).

If your file is not already a "jpeg" or "jpg" file then select JPG in the 'Format" drop down menu.

A better way, since you have the chance to compress and rename the file, as well as resize it is to use iResize, a free application you can get here:

http://www.daniele.ch/iResize.sit

Here's a quick-start guide - you may want to adapt this with experience:

  • Create a new folder on your desktop called, say, IMC
  • Launch iResize
  • Drag and drop a picture into the large window with the red line at top.
  • Change 'New size in pixels' to 500. If it's wider than it is high, select 'Width', otherwise select 'Height'
  • Give your picture a new name (This will be helpful when you come to publish it) and save it to your IMC folder.
  • Repeat with further pictures.

This will compress your pictures as well as resizing them, making them appear more quickly on indymedia, and is good for most pictures.

If you find there are 'artefacts' - strange blurry lines round things like type - then you can re-do the picture using the 'Options' button in the 'Save' panel. Simply increase the Quality slider to 'High' and save it again. (Double click the new image to check it in Preview).

Try never to use 'Best'. It won't look any better on the website and your article will take ages to appear.

Windows

Download and install Photofiltre from: http://photofiltre.free.fr/download_en.htm

This brilliant and easy to use free photo editing software is able to quickly edit and enhance digital photos. It is also quite small and therefore a quicker download than other programs (1.6 meg).

Once installed, load each of your selected pictures into photofiltre. The Open File dialog allows one to preview each pic before loading and usefully displays vitals like dimensions, filesize, creation time etc. Any picture file larger than 100KB or so will need to be resized.

First rotate any sideways on pictures by clicking Image/Rotate.

Next you can try auto improving too light or too dark pics by clicking Adjust/ Auto levels... or Gamma correct.

If you make a mistake with any of these operations then you can always revert to how it was before by clicking Edit/Undo.

The last step should be to resize large photos by clicking Image/Image size and typing a number 400 - 640 into the horizontal pixels box. Never increase the size of an already small pic - it will look awful!

It is then recommended to "Save as" the completed picture with a meaningful filename. BIGREDBANNER.JPG will be far easier to identify than DSC28309.JPG. Doing this will make it much easier to select and upload your chosen pictures in the correct order and without duplicating any on the upload page.