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View Full Version : How do I enlarge images without making them blurry?



ZeroSniper0
04-20-2004, 07:46 PM
i use adobe photoshop 6.0 and when i enlarge images, it gets a little distorted. i use the sharpen feature, but it makes the image have jaggy edges and the textures r more pixelated. is there any way to enlarge images without losing the quality?

________
http://www.ctbase.com/uploads/M40A3/.50-caliber.jpg
"We few, we happy few, we band of brothers; for he today that sheds his blood with me shall be my brother."
--William Shakespeare, King Henry V

ZeroSniper0
04-20-2004, 07:46 PM
i use adobe photoshop 6.0 and when i enlarge images, it gets a little distorted. i use the sharpen feature, but it makes the image have jaggy edges and the textures r more pixelated. is there any way to enlarge images without losing the quality?

________
http://www.ctbase.com/uploads/M40A3/.50-caliber.jpg
"We few, we happy few, we band of brothers; for he today that sheds his blood with me shall be my brother."
--William Shakespeare, King Henry V

FLYdude
04-20-2004, 09:04 PM
Generally not possible to do that.

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Demon_Mustang
04-20-2004, 09:16 PM
You can't get detail where there isn't any.

Remember that every picture is made up of little square dots of whatever color. The larger you enlarge them, the more you'll notice the individual pixels, and that's just the way it is.

______________________________________________
"By sacrificing human life to serve their radical visions, by abandoning every value except the will to power, they follow in the path of fascism, Nazism, and totalitarianism, and they will follow that path all the way to where it ends: in history's unmarked grave of discarded lies." - George W. Bush (09-20-2001)

JonZ
04-20-2004, 10:09 PM
Well that's the first thing I learned this year. Like Demon said, pictures are made of pixels, asking the software enlargement is like to asking it to 'guess' what color of the pixels it should pick to fill the gaps around the old pixels.

Basic graphics lesson = picture enlargement is PROHIBITED or proscribed. If you have the original, film or diapositive, rescan it again at larger resolution.

Of course, this rule is basicaly for the graphic industry. Thus making almost every web photos useless for print unless you pay for larger photos.

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I don't speak french sir, I speak 'freedom'

Plastex56
04-21-2004, 01:30 PM
umm there is a way to sort of clear it up.

Make it into a bitmap file. its part of the options I believe. This will allow you to enlarge and zoom with out as much or little distortion.


If had Adobe 6 and knew how to use it could give you more details.

cuski
04-21-2004, 01:54 PM
Dude, Plastex... please, get a clue.

Unlike "criminology" movies show, enlarging it without blurring it, is technically impossible.

If you use Photoshop, you could change the resizing algorithm - to use Nearest Neighbour or Bilinear instead of the Bicubic default... but you will end up with pixelation instead of blurriness.

RMC.SBS
04-21-2004, 02:05 PM
When you watch films,tv programmes,especially "24",or "CSI",and they say "....Now enhance"from a grainy blurry photo or CCTV camera shot,and then hey presto a lovely clear picture...heheh,makes me laugh everytime. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-very-happy.gif


http://free.one.picturehost.co.uk/rmcstone1.jpg

Livoff
04-21-2004, 03:39 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Dude, Plastex... please, get a clue.<HR></BLOCKQUOTE>

Just to clarify: you can enlarge a picture without blurring it http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif that's what you do when you stretch an image in paint. In other programs like windows image and fax viewer, you don't normally enlarge the picture without blurring it.

If you want a huge poster with the original super mario fron Nintendo 8-bit console, then you have to enlarge the image without blurring it.

Perhaps that's not what the original poster ment, but we haven't found out yet beause everybody started smart-assing around and insulting eachother.

dudes... please get a clue

http://ubbxforums.ubi.com/infopop/emoticons/icon_cool.gif

cuski
04-21-2004, 04:20 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Livoff:
Just to clarify: you _can_ enlarge a picture without blurring it http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif that's what you do when you stretch an image in paint. <HR></BLOCKQUOTE>

And when you do, you end up with pixelation. Read my post again. The point of the original poster is that he wants to enlarge images without losing the quality. Which is impossible. QED.

Livoff
04-21-2004, 04:24 PM
... Not more or less pixelation than in the original picture.

Not QED: If you replace every pixel with four of the same color, you get a larger image. I wouldn't say that it has lost quality ... http://ubbxforums.ubi.com/images/smiley/16x16_smiley-indifferent.gif

My point is that plastex didn't deserve the bashing, although he could have been more clear in his explanation.

When I had Image analysis at university we actually did some pretty cool stuff like histogram operations and statistical operations that would be worthy to show on CSI.

But The most far-out image analysis in movies gotta be blade runner, where thay keep "enhancing" then rotating and then continue "enhancing" http://ubbxforums.ubi.com/images/smiley/16x16_smiley-very-happy.gif

[This message was edited by Livoff on Wed April 21 2004 at 03:34 PM.]

ZeroSniper0
04-21-2004, 04:47 PM
ok cool, thx guys http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif. i just took my image and rescanned at the highest resolution possible http://ubbxforums.ubi.com/images/smiley/16x16_smiley-very-happy.gif. gonna b hell on my printer...

________
http://www.ctbase.com/uploads/M40A3/.50-caliber.jpg
"We few, we happy few, we band of brothers; for he today that sheds his blood with me shall be my brother."
--William Shakespeare, King Henry V

Livoff
04-21-2004, 04:54 PM
Cuski, I'm not trying to be a know-it-all here, I just oppose the bashing when there are several ways to interpret the original question, that's all http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif

FLYdude
04-21-2004, 04:58 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Livoff:
Not QED: If you replace every pixel with four of the same color, you get a larger image. I wouldn't say that it has lost quality ... <HR></BLOCKQUOTE>

If you wouldn't say that, you would be wrong. A larger picture at the same resolution will allow you to see individual pixels more easily. Try zooming in to an extreme level, and then check out the quality. It doesn't look very big, because you see individual pixels. In order for image to appear normal, pixels have to be very small. (note: the pixels themselves are never enlarged in an enlarging of a picture, but you get that effect by filling in 4 pixels with the same color (one big pixel)).

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Livoff
04-21-2004, 05:13 PM
In image analysis, the term "Image Entropy" is used to describe the amount of information per pixel. If replace every pixel with four of the same color you get a larger image, with lower entropy.

I wouldn't say that the image has lost quality, because it showes the same thing as the original image with the same detail level, just larger.

I'm sorry, you can't win this one http://ubbxforums.ubi.com/images/smiley/16x16_smiley-tongue.gif

Hornet57
04-21-2004, 07:24 PM
You are all wrong! http://ubbxforums.ubi.com/images/smiley/mockface.gif

http://www.forumsigs.com/users/Hornet24811111/SIG2.jpg

ghost397
04-21-2004, 08:02 PM
Well, you've already rescanned your image, which is the best thing to do. BTW, for your printer, you likely don't need anything more than a 200dpi image at 100% (and that's a pretty high quality print). So if you scanned it in higher than that, you might lower it and save yourself some file size.

Now, for the most part the rants in this thread have been correct - upsizing an image is a big no-no, you will lose quality every time. However, there IS a trick in Photoshop to enlarge images with a *minimal* loss in visual quality.

Open up the Image Size dialogue, and make sure that resample is selected and set to bicubic. Then change the units of your image size to percent (it probably defaults to pixels or inches). Then increase the image size by 10% (in other words, type in 110%). Then click ok. Do this as many times as you need to in order to get the image size you want.

Things will blur up a bit, but this method should get you much better results than going directly to your desired enlargement size. And some careful use of the Unsharp Mask filter (if that's in 6... I don't remember) should do a decent job of cleaning that up.

This tip comes from any of several books by Scott Kelby. Look him up in your local library.


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"...the Goddess could not spend all Her time persuading
the Kings and Queens of the world of the idiocy of war.
Therefore She invented tacticians..." - Diane Duane

Demon_Mustang
04-21-2004, 10:05 PM
You guys are so weird, the person already figured it out. Get over it. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-very-happy.gif

______________________________________________
"By sacrificing human life to serve their radical visions, by abandoning every value except the will to power, they follow in the path of fascism, Nazism, and totalitarianism, and they will follow that path all the way to where it ends: in history's unmarked grave of discarded lies." - George W. Bush (09-20-2001)

rossd287
04-22-2004, 01:53 PM
What Plastex ment was convert the image to a bitmap file and he was correct. But notice he didnt say "clear it up completly" He said that it will blur "slightly". Of course it wont make it crystal clear but it will allow you to enlarge it with out the distortion of a jpg. or gif. trust me iv gone trough flash and thats what you use to make "prettyier" pictures.

JonZ
04-22-2004, 04:07 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by rossd287:
What Plastex ment was convert the image to a bitmap file and he was correct. But notice he didnt say "clear it up completly" He said that it will blur "slightly". Of course it wont make it crystal clear but it will allow you to enlarge it with out the distortion of a jpg. or gif. trust me iv gone trough flash and thats what you use to make "prettyier" pictures.<HR></BLOCKQUOTE>

Well of course if you enlarge images for the 72 dpi screen purpose or for Flash like you said, it is likely that the enlarged image's quality at some certain percentage will not be affected much.

But as for printing... chances are they will print blurry unless they are printed near their respective resolution. And again like Mustang said, 0Sniper solved the problem and did what I recommended anyway (and seems to have worked for him).

PS what we see in the movies is perhaps fictions (I dont watch CSI or 24), or not!. But make me think about NASA, which they developped some imagery analysis technology that do almost same thing we talk about. They used that technology to find out the causes of Columbia disaster captured on TV cameras when it launched. But still not near at all with Blade Runner http://ubbxforums.ubi.com/infopop/emoticons/icon_biggrin.gif

[fuglyornotstolemysig!]

I don't speak french sir, I speak 'freedom'

[This message was edited by JonZ on Thu April 22 2004 at 08:29 PM.]

FLYdude
04-22-2004, 06:54 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Livoff:
I wouldn't say that the image has lost quality, because it showes the same thing as the original image with the same detail level, just larger.<HR></BLOCKQUOTE>

Well, how do you define quality? You're right in that the image will be same after enlarging, just... larger. But, the larger pixels will allow you to see pixelation more easily. I think pixelated pictures can be considered to be of lower quality than unpixelated ones.

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Thoramir
04-22-2004, 09:03 PM
Yes, you can enhance and enlarge a digital image. Hasn't anyone here heard of Fast Fourier Transforms? They use them in signal and image processing. Don't make me brush up on them and teach everyone a math lesson! I hated that part of my calculus II class and guess which part I ended up doing a project on, signal and image processing. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-indifferent.gif These forums aren't much good for mathematics and I would probably have to explain the notation to most of you. Let me just say this, didn't they have you guys (and gals) draw and/or figure out equations based on a few dots on a cartesian grid? A computer can do the same thing. http://ubbxforums.ubi.com/infopop/emoticons/icon_wink.gif However, it's probably not nearly as dramatic as most TV shows and movies.

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Yeeeeaaaaarrrrgggghhhh!