Resize jpg images
The advantages of resampling
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When working on jpegs, deciding whether to resize jpg images or to resample them is easy.
Taking the way of resampling instead of only resizing is self-evident.
For the differences between resizing and resampling, read the resize photo page.
At that page, we stated that photos should always be resized through a resampling algorithm because the result is smoother.
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Nothing is easier to resample than a jpg image
-jpeg file- because:
Applying a resample algorithm needs a 24 bit color depth image
-a 16 777 216 color image-
A jpg image
IS a 24 bit color depth image
-a 16 777 216 color image-
Except for greyscale jpg photos. Greyscale jpg images are 8 bit depth images
-256 grey tone images-.
But don't worry, to resize jpg images with a 256 grey tone definition through a resampling algorithm is possible too.
You see, NO problem at all with jpg
-jpeg-, it is the ideal image format when you want to resample your images
-i.e. to resize jpg through a resampling algorithm-
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Where is the resize image or resample image function?
Most photo editors either have a resize button in the tool bar or you will find the function under the menu image.
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Even if your image is NOT a jpg
To resize jpg images through a resample algorithm is also an actual subject if your image is not saved as a jpeg image file. Why that?
If your image is saved in another image format
-that may NOT have a color depth of 24 bit- you can not directly resample it.
But if you transform your image into a 24 bit color depth image
-16 777 216 colors- than you can resample it!
You have two ways to attain this:
Either your image editor has a function that allows you to modify the color depth explicitly
Or it has no such function. Than you may open your image that is in another format and subsequently save it as a jpg image.
By saving it as a jpg, the color depth will be modified implicitly. And bingo, you can resize this image through a resample algorithm.
A practical example would be to go through jpg when you want to resample a gif image.
Read all the advantages and disadvantages of doing so at the
resize gif page.
