Using new version, 3.5.2: How do I crop/save without losing

[Muse]

I selected a rectangle containing ~60% of the area of the original JPG, and did a Save As, changed the name and the resultant JPG is about 1/3 the size of the original on disk. I have to believe that the resolution was compromised. How can I retain the original resolution? Just downloaded and installed today, so I'm as noobie as they come here. I don't see any options, no way to alter the editing/cropping/save as settings for JPG quality. Thanks.

[Sarkut]

Muse,

If you reduce the height and width dimensions by 60% each,

that would give you pixel count that is 36% of the original,

and would work out about right.

.60 X .60 = .36

Just over a third.

Is that it or am I off track?

[Muse]

Muse,

If you reduce the height and width dimensions by 60% each,

that would give you pixel count that is 36% of the original,

and would work out about right.

.60 X .60 = .36

Just over a third.

Is that it or am I off track?

No, I didn't measure but my estimate was that I reduced the dimensions enough to reduce the area by 40%.

I just did another experiment. I took a JPG that's about 1.4 MB, cropped a tiny bit off an edge, changed from the default 95% quality (I just noticed that slider when doing the Save), and the result was ~800 kb. Doing the same thing, sliding the quality up from the default of 95% to 100% caused the resulting saved JPG to be 1.7 MB! Seems strange the amplified variation when you consider that the difference (whatever it is) is from original to 95% to 100%. I'm trying to get a handle on what's going on here when I want to crop my photos, something any digital photographer is going to want to do in most circumstances. What are the issues?

[BoltBait]

In my opinion, you should be saving your pictures in a lossless (PNG) format. If you continue to open/save, open/save, open/save your pictures, they will eventually look awful as JPG is a lossy format.

[yellowman]

When you open the jpg file (or any image format) in PDN, it will converted to another format ( I believe it is bmp) to deal with, and when re-save it again the program will re-converted again to the chosen saving as format, so during these two conversions a lot of changing in quality is happening, and regarding the file size as well, That's what I am thinking, it might be wrong.

[Muse]

When you open the jpg file (or any image format) in PDN, it will converted to another format ( I believe it is bmp) to deal with, and when re-save it again the program will re-converted again to the chosen saving as format, so during these two conversions a lot of changing in quality is happening, and regarding the file size as well, That's what I am thinking, it might be wrong.

What is PDN?

OK, please by way of example (this is exactly what I'm up to at the moment, so it's going to help me with today's project), I have 70 JPGs, taken with a 3.1 MP P&S, and they are around 1.4 MB apiece, taken at the max res of the camera. Most could use a little cropping. They are shots of paintings, all done on a tripod. I want to send them to relatives, will post a zipfile containing all on yousendit. I want to crop them but I don't want to degrade the quality, or if that's unavoidable, I want to degrade as little as practically possible. What means should I use here? Should I just zip them up without cropping? Thanks for the help.

[Sozo]

PDN = Paint.NET

If I were you, I would go over into the plugins section and find the OptiPNG plugin, add it to Paint.NET, and use the OptiPNG setting to save your cropped images.

[yellowman]

It all depend on how they gonna use them, if your relatives are planning to print them as they are in large prints and the same quality is needed, then "in my opinion" is just to send the originals without any cropping, and the best way is to do the cropping on the printer itself during the printing process, or print the whole image and trim (cut) the prints to the desired size and aspect ratio, without involving any program editor,

[Muse]

It all depend on how they gonna use them, if your relatives are planning to print them as they are in large prints and the same quality is needed, then "in my opinion" is just to send the originals without any cropping, and the best way is to do the cropping on the printer itself during the printing process, or print the whole image and trim (cut) the prints to the desired size and aspect ratio, without involving any program editor,

Thanks, interesting ideas. Actually, I kind of doubt that these folks will be printing them at all. I have been wondering about these issues, though, for some time. My current camera (I am researching getting another or maybe 2 other cameras) doesn't do a good job of framing shots, so I have to do some guesswork when activating the shutter. Obviously, any photographer is more apt to have excess in the frame than not enough, and cropping is something they have to do a lot. Unless they're using a lossless format, they have the same issues. I didn't even know that cropping a compressed photo will compromise the quality of the original. I think my next camera will support RAW format, but I don't know how much I'll use it. I have no experience with it.

I'm going to try that plugin!

PS The above suggests that when shooting a compressed format such as JPG it's a good idea to frame your shot carefully so that cropping isn't necessary. Well, it's an incentive to do so!

What printer lets you crop at the printer? I don't have a color printer, anyway. However, if and when I do get one I suppose I could use software to crop, such as Pagemaker (which I do use, version 6.5) in which I can crop edges, presumably without sacrificing resolution (?).