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How do I increase this image's resolution?

Thread starter #1
compressed.JPG This image looks to have had its resolution reduced by a factor of 8 after going through DCT compression,how do I increase its resolution so that its stops the blurriness.
 

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DerStrom8

Super Moderator
Most Helpful Member
#3
Thread starter #8
Resolution is lost!!!! Unless you have the original... Photoshop can approximate but the blurriness will always be there.

Do you not have the original???
yes I have the original, how is resolution lost?I did this in matlab and I am not sure if photoshop would be permissible in this instance.
Could this mean there's something wrong with my code?
I was doing DCT compression btw.
 

Ian Rogers

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Most Helpful Member
#9
If you compress a file down to "x" resolution and maintain the picture quality... It's impossible to go back...

If you are trying to save memory space, consider encoding... There are many ways of retaining the picture details.

You need a decent picture encoding C routine.. Jpeg or Gif
 
#10
Hi!
For uploading images you can use Imgur. There you can upload from your computer and you can share it with many link variants (BB Code, link, short link,...). This is how I post images in this forum (BB code for forums).
I was doing DCT compression btw.
Compression is not a recommended thing to do with an image that you are going to use in full size. Compression is useful only when you need the image in small size (for example you want to use that image as a profile photo and the size of the picture is larger than the maximum allowed). The quality of the image after compression is dependent on the photo editor, but generally the quality is lost...

Andrei
 
Thread starter #11
If you compress a file down to "x" resolution and maintain the picture quality... It's impossible to go back...

If you are trying to save memory space, consider encoding... There are many ways of retaining the picture details.

You need a decent picture encoding C routine.. Jpeg or Gif
Ok I get you, so this might be because I didn't encode the image
 

Ian Rogers

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Forum Supporter
Most Helpful Member
#12
Are you trying to save memory space by DCT compression??? I thought it was mainly for audio not picture as its Discreet Cosine Transformation.... I know it has been used but surely JPEG would be easier...

If you are encoding a picture BUT!! on decoding the image is as your photo, then yes! You have an issue in your code!!
 

crutschow

Well-Known Member
Most Helpful Member
#13
If you don't want to lose any image information when you compress it then you need to use a lossless image compression method such as PNG.
Such methods don't provide as much compression as the lossy ones, such as JPEG (which uses DCT), but they retain all the image information.
 

Inquisitive

Super Moderator
#17
Google images search for "lena" she has been on the internet for a while.
 

atferrari

Well-Known Member
#19
First time I saw that image was in the Don Lancaster's colum in the US ???? magazine. He used it precisely to discuss something like resolution, grey scales or related with that.

Maybe you could find it in his site.
 

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