Resizing photos for this site

[FUDGEY]

Can anyone please tell me the maximum size of photos you can put on this site? My photobucket wont let me resize and I am going to do it on photoshop. Any help greatly received thanks

[Stinky Bob]

This is from the help for pictures going into the Gallery:
Image Sizes

Images should be at least 800x600 (not 600x800), and can be as large as you like, but they'll be automatically resize to a maximum width or height of 1600 pixels. On occasions, we may accept smaller photos if they are of rare subjects or unusual circumstances.

[eeyore]

Originally Posted by Stinky Bob

This is from the help for pictures going into the Gallery:
Image Sizes

Images should be at least 800x600 (not 600x800), and can be as large as you like, but they'll be automatically resize to a maximum width or height of 1600 pixels. On occasions, we may accept smaller photos if they are of rare subjects or unusual circumstances.

note tho that although they can be as large as you like in dimensions the file size is limited to 500kb (250kb prefered) which means that you cant practically go too large on dimension either.

I usually resize mine to 880x660 at 72 ppi and resave at quality setting 7 in photoshop

[Geoff F]

Are you talking about the Forum or the Gallery? Forum images can be smaller.

For the Main Gallery I normally use 1020 pixels wide (average screen size) for landscape aspect or 900 pixels wide for portrait aspect and 96 pixels per inch. 72 is commonly used which is an American preference but (I think) most European monitors use 96 ppi.

I compress the Jpegs to 90% although 80% will save more space without too much loss of quality.

The best settings are really just a matter of personal opinion providing you are in the approximate size range.

How to resize and retain maximum quality is a bit of a technical issue, which can quickly get complicated.

However, trying to put things briefly. When doing a considerable downward resize (say from 3000+ pixels to 1000 approx) I do it in 2 stages and use the BiCubic Interpolation setting, or Best Quality, and after resizing I use a little Unsharp Mask to firm up the image which can become a bit soft after resizing. You want it to be sharp before Jpeg compression which can lose some details. Say a setting of 30 to 50% at 1 pixel radius; although opinions on what is the best setting can vary.

One other point, cropping an image before resizing can sometimes save wasting space on pointless edge background and give the subject more prominence; but it all depends on the image in question.

[eeyore]

Originally Posted by Geoff F

I do it in 2 stages and use the BiCubic Interpolation setting, or Best Quality, and after resizing I use a little Unsharp Mask to firm up the image which can become a bit soft after resizing. You want it to be sharp before Jpeg compression which can lose some details. Say a setting of 30 to 50% at 1 pixel radius; although opinions on what is the best setting can vary.

.

strictly speaking you shoulnt use the bicubic interpolation setting for downsizing - only for upsizing.

Interpolation is basically asking the computer to caculate the colour of new pixels based on the colour of those surrounding it - therefore if upsizing you should go up in incremental steps so it only has to caluculate a few at a time - however going down you dont need the interpolation because there are no new pixels to colour in.

[Lancashire Lad]

Originally Posted by Stinky Bob

....Images should be at least 800x600 (not 600x800), and can be as large as you like, but they'll be automatically resize to a maximum width or height of 1600 pixels. On occasions, we may accept smaller photos if they are of rare subjects or unusual circumstances.

There is conflicting information on the site, and depending on which section you read, will determine (size wise) whether your images will be accepted or not.
On the actual Gallery upload page it specifically states that images must NOT be larger than 1600 x 1600 pixels.

Full details on how to upload to the Gallery without falling foul have already been posted - if only people would take the trouble to read what's been written.
http://www.wildaboutbritain.co.uk/fo...tml#post541977

Regards,
Mike.

[Geoff F]

Originally Posted by eeyore

strictly speaking you shoulnt use the bicubic interpolation setting for downsizing - only for upsizing.

Interpolation is basically asking the computer to caculate the colour of new pixels based on the colour of those surrounding it - therefore if upsizing you should go up in incremental steps so it only has to caluculate a few at a time - however going down you dont need the interpolation because there are no new pixels to colour in.

That was the advice when I started learning digital editing around 8 years ago; but current thinking tends to suggest that with today's massive image starting sizes it is better to use BiCubic when doing a substantial downsize.

When starting with, say for example, more than 3000 x 2000 pixels and ending up with around 800 x 500 approx it means that a lot of pixels are being discarded.

My photo editing programme (Serif Photo Plus X3) recommends BiCubic (or better) for substantial resizing in either direction; however, I have asked this question on the Cambridge in Colour photo forums site to see what is the general opinion on this subject worldwide.

I will report back.

[eeyore]

Originally Posted by Geoff F

That was the advice when I started learning digital editing around 8 years ago; but current thinking tends to suggest that with today's massive image starting sizes it is better to use BiCubic when doing a substantial downsize.

When starting with, say for example, more than 3000 x 2000 pixels and ending up with around 800 x 500 approx it means that a lot of pixels are being discarded.

My photo editing programme (Serif Photo Plus X3) recommends BiCubic (or better) for substantial resizing in either direction; however, I have asked this question on the Cambridge in Colour photo forums site to see what is the general opinion on this subject worldwide.

I will report back.

okay i stand corrected - but could you explain why ? as its hard to see how interpolation helps when downsizing an image (incidentally when upsizing i generally use "genuine fractals" as imo its marginally better than the photoshop bicubic alogorythm)

[Geoff F]

Yes I agree there are even better methods than BiCubic which is why I said 'BiCubic (or better)' My software has a method which they call Lancoz Window (if that is the correct spelling).

On the Cambridge in Colour site the experts, so far, all recommend BiCubic or better (Best Quality in some programmes) when resizing in both directions. There is a suggestion that using BiCubic Sharpener when resizing downwards avoids having to give your images a slight Unsharp Mask afterwards. But use BiCubic Smoother for upsizing. Remember though, these guys are using £1000 approx software so this isn't an option for most of us.

As I understand the theory, and I am getting out of my depth now. BiLinear adds 'suitably informed' pixels up and down plus left and right to the original pixels, as required. But this leaves the diagonals confused, which is where BiCubic can calculate the correct attributes for these diagonal additions.

The same theory applies in reverse and avoids leaving the diagonals confused.

At least that's my theory. Actually, I found that I could understand this idea better by mentally changing pixels to pixies. They are standing in a block and have a choice of red, green or blue hats and selecting the correct colour of their hats creates an image.

If you image them standing closer together or further apart we have an explanation of resolution. When the image is resized, extra pixies run into the group to make a larger image and they look at the colour of their neighbour's hats to decide which colour they should be wearing.

I know it's a silly idea but it worked for me!