Linked Questions

3 votes
2 answers

How can I simulate JPEG quality degradation? [duplicate]

I am writing a report about file formats in images & their properties. In the report I want to talk about how file formats have lossy compression rather than lossless compression & I wanted to ...
Pi Net's user avatar
  • 33
26 votes
12 answers

Does simply opening and closing a JPEG file decrease image quality?

I've had quite a few photography classes, read many photography books, and screened many forums. And I can't find a consistent answer to this question. One "camp" says there is a loss of image quality ...
markthomas's user avatar
  • 1,193
11 votes
8 answers

What is the "optimal" file size of JPEG images with respect to their dimensions?

I plan to write a script that will scan 100,000+ JPEG images and re-compress them if they are "too big" in terms of file size. Scripting is the easy part, but I am not sure how to categorize an image ...
Salman A's user avatar
  • 249
5 votes
8 answers

My mentor says to set image to Fine instead of RAW — how is this different from JPG?

So far, I have heard of one reason to have the camera save images as RAW instead of anything else. JPEG is a lossy form of image data and so I always thought it made sense to save the image data as is ...
perennial_noob's user avatar
7 votes
7 answers

Is a JPG guaranteed to produce the same pixels?

I know there are plenty of benefits to shooting in RAW, but at the moment it seems that JPG works just fine for me. The file sizes are way smaller, and darktable seems to work just fine with them (...
Wayne Werner's user avatar
  • 1,251
9 votes
3 answers

Does JPEG-to-JPEG export Lightroom reapply compression?

I want to crop a JPEG file in Lightroom and export that cropped file to another JPEG so that I can e-mail it. The exported JPEG should have the same quality as the original. I don't have the RAW file ...
Saaru Lindestøkke's user avatar
11 votes
2 answers

Is it worth using Pentax's Premium JPEG quality setting?

Similar: How do I choose which resolution (megapixel) and compression (normal, fine, superfine) to shoot in? The Pentax K-5 has a JPEG quality setting called "Premium", denoted by four stars, which ...
bwDraco's user avatar
  • 5,936
4 votes
4 answers

What image quality is lost when re-saving a JPEG image in MS Paint?

Has anyone ever noticed that if you open a image in mspaint (.jpg, .jpeg) and then just save it, the image size is reduced by many folds. I use this method to reduce the file size. However, I am not ...
Ankit's user avatar
  • 143
7 votes
2 answers

Does converting image file formats affect quality?

Does converting image formats, such as from JPG to PNG, have any effect on image quality? I know converting from RAW to JPG has disadvantages, but what about other format conversions?
Mahesh Mankar's user avatar
0 votes
2 answers

GIMP Quality .jpg export - what is the best set up? [duplicate]

please could you tell what is the best common quality export value for .jpg image export in the GIMP? For example I set up the 100% for .jpg and for example for image 1,5 MB I will get the 5,2 MB or ...
Heron's user avatar
  • 217
3 votes
4 answers

GIMP: Why can I set a higher quality than original image in the "Export Image as JPEG" dialog?

After having read the GIMP Export Image as JPEG section, I still have one understanding issue: Why am I able to select a higher quality value than the one from original image in the export dialog? For ...
bela53's user avatar
  • 133
2 votes
2 answers

Why does GIMP increase the size of exported JPEG files?

I'm using GIMP to edit some vacation pictures (JPEG files) taken with a rather old digital camera. Lacking a professional background, I just went about by trial and error and ended up adjusting the ...
david's user avatar
  • 121
0 votes
2 answers

Trying to understand losses in jpg compression

I have a bunch of jpegs taken with a Nikon D3200 at 6016 x 4000. They weigh between 9M and 12M each. To try and reduce space a bit, I compressed copies with the default Windows utility, and the new ...
Martin Argerami's user avatar
2 votes
1 answer

Why do some pictures rotated with exiftran have a vertical line on the right?

I use the following command in a script: exiftran -a -i mypic.jpg For some pictures, I get a wrong vertical offset, which is seen as a vertical line along the ...
gb.'s user avatar
  • 241
2 votes
1 answer

Does compressing with chroma-subsampling multiple times degrade image quality?

Suppose I am creating a large image files out of smaller ones. The original images (jpeg) already have chroma-subsampling of 4:2:0. If one were to put them together and save again as a jpeg, would ...
Elie's user avatar
  • 67