Lossless JPG crop at set size or proportion?

1492 views10 repliesLast post: 4/24/2007
I use JPEGCrop to crop JPEG files. It works fine but I am looking for a cropping tool that can crop at certain ratio (eg. 4x3) or predefined size (eg. 800x600). I've read some posts here but still can't find an answer.

Thanks for the help,

liu
#1
On 21 Apr 2007 21:10:18 -0700, cpliu wrote:

I use JPEGCrop to crop JPEG files. It works fine but I am looking for a cropping tool that can crop at certain ratio (eg. 4x3) or predefined size (eg. 800x600). I've read some posts here but still can't find an answer.

Thanks for the help,

liu

are you running any of the CS versions?

Dave
#2
On Apr 22, 12:33 am, Dave wrote:
On 21 Apr 2007 21:10:18 -0700, cpliu wrote:

I use JPEGCrop to crop JPEG files. It works fine but I am looking for a cropping tool that can crop at certain ratio (eg. 4x3) or predefined size (eg. 800x600). I've read some posts here but still can't find an answer.

Thanks for the help,

liu

are you running any of the CS versions?

Dave

I use Photoshop 7 although I have access to CS2. Does CS2 have lossless JPEG?
#3
"cpliu" wrote in message
On Apr 22, 12:33 am, Dave wrote:
On 21 Apr 2007 21:10:18 -0700, cpliu wrote:

I use JPEGCrop to crop JPEG files. It works fine but I am looking for a cropping tool that can crop at certain ratio (eg. 4x3) or predefined size (eg. 800x600). I've read some posts here but still can't find an answer.

Thanks for the help,

liu

are you running any of the CS versions?

Dave

I use Photoshop 7 although I have access to CS2. Does CS2 have lossless JPEG?

I have never heard of lossless Jpeg! every time you save a jpeg you are given a choice of compression and even at the least compression there will be some loss however minor!
#4
On Sun, 22 Apr 2007 09:24:06 +0100, "Harry Limey" wrote:

"cpliu" wrote in message
On Apr 22, 12:33 am, Dave wrote:
On 21 Apr 2007 21:10:18 -0700, cpliu wrote:

I use JPEGCrop to crop JPEG files. It works fine but I am looking for a cropping tool that can crop at certain ratio (eg. 4x3) or predefined size (eg. 800x600). I've read some posts here but still can't find an answer.

Click on the 'Crop Tool' and simply type the width and height in the windows supplied therefore

Dave
#5
cpliu wrote:
I use JPEGCrop to crop JPEG files. It works fine but I am looking for a cropping tool that can crop at certain ratio (eg. 4x3) or predefined size (eg. 800x600). I've read some posts here but still can't find an answer.

There definitely is a lossless JPEG standard, but I've never looked for it in CS*. Max size will probably suffice.

I am not sure you really mean to crop, which would remove content. Perhaps you just mean to certain sizes.

For that in CS, go to File - Automate - Fit Image and type in the dimensions. Batch it and be happy.

If you have CS2 you might look to File - Automate (or Scripts) - Image Processor.
#6
In article ,
Dave wrote:

Click on the 'Crop Tool' and simply type the width and height in the windows supplied therefore

That's not what he's looking for.

"Lossless JPEG cropping" is a procedure where a JPEG file is cropped to a set size without being opened and re-saved. The JPEG image is cropped without introducing further loss.

Photoshop can not do this. Any Photoshop operation on a JPEG involves uncompressing and then re-compressing it, resulting in cumulative loss.

--
Photography, kink, polyamory, shareware, and more: all at http://www.xeromag.com/franklin.html
#7
On Sun, 22 Apr 2007 20:55:43 -0400, tacit wrote:

In article ,
Dave wrote:

Click on the 'Crop Tool' and simply type the width and height in the windows supplied therefore

That's not what he's looking for.

"Lossless JPEG cropping" is a procedure where a JPEG file is cropped to a set size without being opened and re-saved. T

Keep in mind that the word 'Lossless' whas only mentioned in the 2nd posting wich was the reply on my post.
What I said was a answer on the question in his first letter. The question about Loslless Cropping was asked as if it was a second question.

Dave
#8
"Lossless JPEG cropping" is a procedure where a JPEG file is cropped to a set size without being opened and re-saved. The JPEG image is cropped without introducing further loss.

none the less, thanks for this explanation.

Dave
#9
john wrote:

There definitely is a lossless JPEG standard, but I've never looked for it in CS*.

There is and it is poorly supported. However, that is not what happens with a lossless JPEG crop. Within some constraints (the upper left corner needs to be aligned to the underlying structure of the JPEG), lossless cropping of standard JPEGs works just fine.

The programs that support it reuses the compressed blocks from the original JPEG, thus bypassing any lossy recompressing.

A list of such programs can be found at
http://sylvana.net/jpegcrop/losslessapps.html
They all support the well-known lossless rotation and some of them support lossless cropping (which strictly speaking is an oxymoron). --
Toke Eskildsen - http://ekot.dk/
#10
On 23 Apr 2007 21:21:12 GMT, Toke Eskildsen
wrote:

A list of such programs can be found at
http://sylvana.net/jpegcrop/losslessapps.html
They all support the well-known lossless rotation and some of them support lossless cropping (which strictly speaking is an oxymoron).

I don't think that "lossless jpeg cropping" is an oxymoron. It's pretty clear that the ides is that the cropped section *itself* is lossless - that it contains the same data as in the original with no data loss introduced thru additional jpeg compression after cropping.

jc

--

"The nice thing about a mare is you get to ride a lot of different horses without having to own that many." ~ Eileen Morgan of The Mare's Nest, PA
#11