Image Resizing Frustrations

[Donald]

I know that there have been many discussions and I have been over Sean's tutorial on the subject in fine detail, but ....!! And, because I use the GIMP, I've got the Sinc/Lanczos alogorithms available that Sean suggests produces best results.

This,below, is a pale imitation of the full size image. As you can see in the bottom half, there are lots of leaves on trees. For me, the full size (thanks, I'm sure, to the 70-200f4L IS rather than me) just flys. Every leaf pops and I'm terribly pleased with it.

Taking it down loses so much of the detail and the leaves become just a 'blob' of colour. And, because of that, I think, it loses the contrast that was there and, indeed, seems to alter the colour. I've been blurring and sharpening .. and sharpening and blurring .... and saying naughty words! The full size is 3906 x2602.

How would you re-size to keep as much of the detail as you could? Do you know the secret? Or am I just facing one of the consequences of re-sizing an image such as this for the web?

[KentDub]

Or am I just facing one of the consequences of re-sizing an image such as this for the web?

I believe yes, you are. While some might claim the image is slightly oversharpened (hinted to by the white specs showing up), I don't think that is the main issue here. It sounds like you're like me, and hate seeing quality reduced - especially images such as below, which call for high resolution.

For shots like this that contain so much high-frequency detail, I would recommend putting a link next to the image to the full resolution version (which I would love to see btw).

[wjh31]

For shots like this that contain so much high-frequency detail, I would recommend putting a link next to the image to the full resolution version (which I would love to see btw).

my sentiments exactly, a link to full size gives anybody the chance to view an image in its full glory, and most people will be able to tell that images like this are best viewed larger.

[Donald]

Kent

Many thanks for your constructive feedback. Here's the full size version http://farm3.static.flickr.com/2724/...d9dcbde4_o.jpg

...and most people will be able to tell that images like this are best viewed larger.

Will

Apologies if I seemed rather stupid. The question was framed as it was on the basis that I knew what problem I had, and was attempting to establish if my knowledge was deficient in terms of trying to get the image inline.

[KentDub]

Wow, lots of detail in the large version, Donald! I would have gone a bit further with output sharpening on the large version. When resizing for the smaller version, try using BiCubic smoother - I know this sounds opposite of what you would normally do. There is so much high-frequency data in this image that the specular highlights on the leaves and branches are becomming white specs in the lower resolution file. While the Sinc/Lanczos are great algorithms, this may not be an ideal time to use them. Give bicubic smoother a shot, and if its a bit fuzzy for your taste then apply output sharpening from there. Post it up and we'll compare

[Dave Humphries]

Hi Donald,

I agree with Kent (and Will, and you) about there just being too much fine detail for such a reduction.

In the past where I have had a similar 'problem', I have only reduced to 1200, or even 1500, rather than my usual 800 or 1000 px widths.

I also agree with Kent that you could push the sharpening some more on the full size version.
His other idea makes a lot of sense to me too.

Cheers,

[Donald]

In the past where I have had a similar 'problem', I have only reduced to 1200, or even 1500, rather than my usual 800 or 1000 px widths.

Hi Dave
Thanks for the comments.

I normally resize to 1024 on the long edge, which in itself caused some decay. But that was compounded by the fact that when using the Flickr upload software, it automatically resizes to 800, which made things worse.

Thanks to Kent's comments I have, this evening, discovered the 'other way' to get larger images uploaded. Ergo - Problem part solved. But that's not the real issue.

Will go at it again with the above advice to hand, over the next couple of days.

As I've written before, the amount of knowledge, experience and willingness to help amongst people on this site, continues to thrill.

[Ashwin]

How would you re-size to keep as much of the detail as you could? Do you know the secret? Or am I just facing one of the consequences of re-sizing an image such as this for the web?

I think this will meet your requirement - resized to 720 - 479.Pixels
In photoshop while resizing image select " BICUBIC SHARPER ( BEST FOR REDUCTION )
option

[Steaphany]

One way to present the full detail of the image is to try Zoomify, they even have a free version that can be used.

Alternatively, when I need to scale images, I use the Studio Edition of QImage

[KentDub]

I think this will meet your requirement - resized to 720 - 479.Pixels
In photoshop while resizing image select " BICUBIC SHARPER ( BEST FOR REDUCTION )
option

That came out well. As I suspected it was indeed the choice of algorithm. Best to try Sinc/Lanczos on other pictures, dosn't seem to work well with this one.

[Donald]

I think this will meet your requirement - resized to 720 - 479.Pixels
In photoshop while resizing image select " BICUBIC SHARPER ( BEST FOR REDUCTION )
option

Ashwin - Many thanks for doing that. I will try to replicate and apply the learning on future occassions.

Steaphany - Never knew you could get such things!!

[wjh31]

Apologies if I seemed rather stupid. The question was framed as it was on the basis that I knew what problem I had, and was attempting to establish if my knowledge was deficient in terms of trying to get the image inline.

I did not atall mean to imply you were stupid, i meant that someone viewing the image will see they are not getting the best from it being shrunk, so would click through to a full sized image given the chance, and so it wasnt worth working yourself up too much trying to get the image looking absolutely perfect resized

hope that makes sense

[Donald]

hope that makes sense

Will

Indeed it does and thank you for your comments. This has been an extremely helpful thread.