How do I enhance low quality JPEG images?

In summary: Not feasible, and third, if he wants to try to fix it, he'll need to have some understanding of image manipulation and compression.
  • #1
ElliotSmith
168
104
Is there any way to enhance low quality and low resolution JPEG images? Is there a program I can use or something?

I have dozens of grainy and poor quality JPEGs that I would like to sharpen up, but I do not own photoshop.
 
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  • #2
Enhancing low quality photos is tough because you need some algorithm to add in data to the image that didn't exist. Photoshop does have some advanced tools for this. Free options do exist but I'm not sure how much they will help. Certainly sharpen filters are common though.

Try http://www.getpaint.net
 
  • #3
To sharpen a picture, look at the "unsharp mask" plugin for paint.net. It's name is deceptive. It actually sharpens edges. It must be used judiciously because it is easy to overdo the effect. Done well, it is can be really improve a dull photo. You can actually see some of that effect in many professional photos and HDTV screen images.
 
  • #4
Unfortunately, unsharp mask tends to increase the "graininess" of an image, i.e. "noise" in areas that are supposed to have a smooth texture. It works best for enhancing soft edges and making them look sharper.
 
  • #5
Andre knew of a good, free online photo editing program that had an excellent noise reduction filter. "Graininess" often means too much noise. Maybe he'll see this thread.
 
  • #6
jtbell said:
Unfortunately, unsharp mask tends to increase the "graininess" of an image, i.e. "noise" in areas that are supposed to have a smooth texture. It works best for enhancing soft edges and making them look sharper.
Good point. The OP mentions both low resolution and wanting to "sharpen" them. I would recommend that he find a friend with Photoshop and test a photo to see what will work. Then he can look for those capabilities in free software. I have seen photos where fractal techniques were used to add artificial detail that looked very realistic.
 
  • #7

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  • #8
Alternatively ''wavelet denoise'' plugin on GIMP , [GIMP and plugins are free] ...
 

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  • #9
Just remember - the image may look better, but as Greg said in the very first answer - it won't have more information than there was in the compressed image. Changes will be only cosmetic, to appease the eye.

Actually in a way they will make the image worse - while it will look better, it will contain other artifacts, not as visible, but still degrading the information stored. You may try to take a picture of a newspaper with different sizes of text (ads, titles, plain text), and then to see which parts of the text can be still read after saving the image with different levels of compression and after applying different filters. My bet is that each additional operation will make the newspaper more difficult to read.
 
  • #10
Borek said:
... My bet is that each additional operation will make the newspaper more difficult to read.

If the brief is to sharpen blurred-text see "SmartDeblur" ...

Before
screen12.jpg


After
resulting.jpg

Now readable, but with plenty of artifacts.
 
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  • #11
Interesting and impressive, but that's not exactly the same thing. If the blur is added in a "systematic" way the information is still in the picture - and it is possible to attempt to recover it. When the image was compressed with the lossy compression situation is different.
 
  • #12
Borek said:
If the blur is added in a "systematic" way the information is still in the picture…

It’s me who should say about this. Not exactly as Borek claims because of rounding errors, but blurring an image in computer’s memory, especially if lossy compression is not applied, inflicts much less data loss than blurring due to physical effects in realistic conditions (such as out of the focus photograph).
 
  • #13
Borek said:
Interesting and impressive, but that's not exactly the same thing. If the blur is added in a "systematic" way the information is still in the picture - and it is possible to attempt to recover it. When the image was compressed with the lossy compression situation is different.
A lot of what makes a photograph look sharp is not the amount of information. I think that HDTV looks good even on a very large screen at a size to which I would hesitate to blow up a photograph. If you figure the photograph pixel count that HDTV is equivalent to, it is less than most cameras. Of course an extremely small pixel count will be hard to fix.
 
  • #14
FactChecker said:
A lot of what makes a photograph look sharp is not the amount of information.

Sure - but first, OP never stated what he wants (just an appeasing effect, or getting more information from the picture), second, my bet is OP is not aware of the distinction (so he can be wasting his time trying to do something that is impossible).
 

1. How can I improve the resolution of a low quality JPEG image?

One way to enhance the resolution of a low quality JPEG image is by using image editing software such as Adobe Photoshop or GIMP. These programs have tools that allow you to increase the image dimensions and adjust the sharpness and clarity of the image.

2. Is it possible to reduce the pixelation and blur in a low quality JPEG image?

Yes, it is possible to reduce pixelation and blur in a low quality JPEG image. This can be done by using the "sharpen" or "deblur" tools in image editing software. These tools work by increasing the contrast between pixels, making the image appear sharper and less blurred.

3. Can I improve the color and brightness of a low quality JPEG image?

Yes, you can improve the color and brightness of a low quality JPEG image. Image editing software allows you to adjust the levels of brightness, contrast, and saturation to enhance the overall appearance of the image. You can also use the "color balance" tool to adjust the color tones in the image.

4. Are there any online tools that can enhance low quality JPEG images?

Yes, there are several online tools that can enhance low quality JPEG images. Some popular options include Fotor, Pixlr, and BeFunky. These tools offer various features such as resizing, sharpening, and color adjustments to improve the quality of JPEG images.

5. What is the best way to prevent low quality JPEG images in the first place?

The best way to prevent low quality JPEG images is to use high quality equipment when capturing the image. This includes using a camera with a high resolution and avoiding low light conditions. Additionally, saving the image in a lossless format such as TIFF or RAW can help maintain the quality of the image.

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