Resizing and Resolution

[alexander]

OK you guns, I have noticed some comments in a couple of threads referring to resizing and resolution. Implying that there is a difference between the two. Particularly about quality with web posting. Can you enlighten this old man with an explanation of the two???????:)

Alex.

[SupremeMoFo]

Resizing = changing how large something will appear at 100%.
Photoshop defines resolution as units in pixels/inch (DPI) or pixels/centimetre. /inch is the standard measurement - 72 dpi is correct for on-screen viewing, 300dpi is correct for printing.

Mostly though resolution will be detailed as the dimensions of the image in pixels - but Photoshop just refers to this as dimensions.

[Axel]

All these difficult questions so early Alex ;)

Resizing is changing the number of pixels in the image.

Example taking a 3000 x 2000 pixel image and resizing to 800 x 600 pixels by combining say every 3 pixels and averaging their colour (fortunately the software does this :) )

Resolution is the fineness of detail - say the number of pixels crammed into an area, the more pixels the higher the resolution.

Example - 10 million pixel image taken with your pentax of a car close up - high resolution image of a car. 10 million pixel image taken from a satellite may be considered low resolution image because the same car may be represented by 5 or ten pixels.

Both 10 megapixel images could be resized to 2 megapixel images which would be lower resolutions but still be comparatively high and low resolution images.

Supremo, just to clarify, 150 or 600dpi could also be correct for printing depending on the size of your print and the distance it will be viewed from.

Have I confused the issue even more? :confused: