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Newbie question: How do I make images larger and retain pixel density?

O

ozreth

macrumors 65816
Original poster
Nov 5, 2009
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Not even sure if I'm asking that correctly. Basically I have a wallpaper that is 1200x900 and want to make it 1440x900 without it becoming blurry.. There have been so many instances that I've wanted to do this but never bothered to figure out how, nows the time.

I've got access to photoshop, so, what do I do? : )
 
ozreth said:
Not even sure if I'm asking that correctly. Basically I have a wallpaper that is 1200x900 and want to make it 1440x900 without it becoming blurry.. There have been so many instances that I've wanted to do this but never bothered to figure out how, nows the time.

I've got access to photoshop, so, what do I do? : )
Click to expand...

You can't increase the pixel dimensions of a bitmap image without lowering the image quality. That's how bitmap images work, I'm afraid.

You can minimize the effect by putting the size up in small stages, allowing Photoshop's bicubic interpolation algorithm to do its work, and even applying tiny amounts of the Gaussian Blur or Noise -> Median filter in between each resizing step, but your larger image is never going to look as sharp as the original smaller one.

Cheers

Jim
 
Jim Campbell said:
You can't increase the pixel dimensions of a bitmap image without lowering the image quality. That's how bitmap images work, I'm afraid.

You can minimize the effect by putting the size up in small stages, allowing Photoshop's bicubic interpolation algorithm to do its work, and even applying tiny amounts of the Gaussian Blur or Noise -> Median filter in between each resizing step, but your larger image is never going to look as sharp as the original smaller one.

Cheers

Jim
Click to expand...

This. Plus you are trying to make it wider than the original image, which will distort it anyway.
 
A couple of years ago my wife switched from a 17" 1024x768 CRT to a 19" 1440x900 LCD and all of her wallpapers were too small. I found as many replacements as possible in the new size but for the ones that I couldn't find higher res versions of I just used Photoshop Elements to make the canvas size 1440x900 filling the added space with black. I know this isn't what you were looking to do, but it does give you a way to use older, smaller wallpapers without distorting them. Gives them a kind of photo gallery look.
 
I see. How about making images smaller without making them look squished? That sounds more plausible : )
 
ozreth said:
I see. How about making images smaller without making them look squished? That sounds more plausible : )
Click to expand...

Just reduce the image size but maintain the aspect ratio. There's usually a box you can check so the same amount is applied to both dimensions.
 
ozreth said:
I see. How about making images smaller without making them look squished? That sounds more plausible : )
Click to expand...

As DewGuy1999 said, always size proportionally (height + width).

And after you reduce the file size, hit it with with an Unsharp Mask, because reducing will blur your image as well.
 
ozreth said:
Not even sure if I'm asking that correctly. Basically I have a wallpaper that is 1200x900 and want to make it 1440x900 without it becoming blurry.. There have been so many instances that I've wanted to do this but never bothered to figure out how, nows the time.

I've got access to photoshop, so, what do I do? : )
Click to expand...
You must crop the image to the new aspect ratio and enlarge it to fill the new pixel map. The order of the cropping and enlargement steps probably doesn't matter a lot, but I would crop after enlarging. If you are using a Photoshop-compatible application, then you should exlarge using a fractal plugin like Perfect Resize, formerly known as Genuine Fractals. It will not create increased resolution, but it is probably the best tool for faking increased resolution of raster graphic images.
 
C'mon image Nazis - 1200 to 1440 isn't that big a resize, and if it's only for wallpaper then, y'know, who gives a ****?

Open up the file in Photoshop, go Image>Image size, make sure "resample image" is checked, go to the top of the dialogue window and bump the width up to 1440 pixels.

Click OK and you will end up with a file that is 1440 pixels by 1080 pixels.

Go to Image>Canvas size, use the drop-down menu to select pixels as your unit type, then reduce the height to 900, thereby cropping the image in the height only.

Voila.
 
covisio said:
Possibly. But then in 9 responses, no-one actually told the guy how to do it.
Click to expand...
You, sir, go to the top of your list. The fact is that several of us have given him a variety of options. The OP makes no mention of a currently installed application that he intends to use. Do you want someone to select an application for him and then give him detailed instructions how to use it?
 
covisio said:
Possibly. But then in 9 responses, no-one actually told the guy how to do it.
Click to expand...

He says he has access to Photoshop, and I told him very clearly how to minimize pixillation when increasing size.

(Do it in several stages, with Bicubic Interpolation when using Image Size, applying small values of Gaussian Blur or Noise -> Median in between each stage if necessary, in case scrolling back to the top and actually reading my post is too much like hard work.)

If he has "access to Photoshop" I'm assuming he knows how to use the Crop tool.

So, again, a little un-called-for.

Jim
 
You gave him some nice background information about the best way to upscale images in general.

In no way did you actually explain how any of that could be achieved. You made an assumption that he knew what gaussian blur is, how it can be used, where to access the functions, etc.

The phrases 'Newbie question', 'access to Photoshop' and 'Not even sure if I'm asking that correctly' led me to assume he hasn't a clue and needs it explaining in baby steps.

I offered the jocular intro of "C'mon image Nazis" as a way of engaging with people whom I assumed had a sense of humour. It was intended to highlight the fact that whilst image professionals like ourselves can get somewhat obsessive about image quality, people like this guy probably do not and just want their wallpaper to look pretty. Seems to have backfired.

Too many assumptions all round - sorry about that.
 
covisio said:
It was intended to highlight the fact that whilst image professionals like ourselves can get somewhat obsessive about image quality, people like this guy probably do not and just want their wallpaper to look pretty. Seems to have backfired.
Click to expand...

I'm all for clarity. When stepping someone through a process I usually try to format my answers in a clear Pull-down Menu > Dialog Box > Settings way too.

But really, give people a little break for speaking in broader terms. Any user worth their salt could search those terms and find step-by-step tutorials. Anybody still unclear on the concept can re-post for clarification.

You instruction Nazi. ;)

You must form you responses in the acceptable way or ve will send you to the showers!
 
covisio said:
Too many assumptions all round - sorry about that.
Click to expand...

I have no qualms about referring to myself as -- for example -- a grammar nazi, but I think you'll find most people are a little sensitive to someone else labelling them a nazi, even with supposedly humorous intent.

No, perhaps I didn't baby-step my instructions enough, but I clearly refer to filters right after saying Noise -> Median. Strangely enough, my time comes at a premium and I figured the OP could always ask if he couldn't figure out what to do from my post. I mean, I didn't post screenshots, or a record an instructional video, either. Was that remiss of me?

Jim
 
Jim Campbell said:
Strangely enough, my time comes at a premium ... I mean, I didn't post screenshots, or a record an instructional video, either. Was that remiss of me?
Click to expand...

I find it interesting to note that the OP has (apparently) gone off happy with the responses he's received, while covizio is now expending more and more of your time asking you to justify your actions than it did to post them in the first place!
 
Jim Campbell said:
You can't increase the pixel dimensions of a bitmap image without lowering the image quality. That's how bitmap images work, I'm afraid.

You can minimize the effect by putting the size up in small stages, allowing Photoshop's bicubic interpolation algorithm to do its work, and even applying tiny amounts of the Gaussian Blur or Noise -> Median filter in between each resizing step, but your larger image is never going to look as sharp as the original smaller one.
Click to expand...


Nice solution Jim. This is very useful info, and I hope this info will help me to solve such problem.
 
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