Rotate images, very lossy

When right clicking on an image file, say jpg, and choosing to rotate that
image... a file that may have been 2MB becomes 1MB. Seems to me that the
image is greatly degraded in quality. So I chose to not use this function.
However it's easy to click on that choice by mistake. I see that I can
highlight all the images in a folder and make them read-only and the rotate
option becomes grayed out. That's a good thing.
But I'm wondering if there is a setting that will up the compression quality
for image rotation. It could come in handy at times when building a slide
show.

Dan

JPG images are what's called a "lossy" image format. Everything you do to a
jpg image file will degrade the quality of the image. Making the files read
only will protect them. The only thing that makes this image format popular
is the extremely small size.

What you can do if you do want to rotate or perform other enhancing of a jpg
file is to first convert it to a "lossless" format such as, TIF, or PNG.
After you make the changes, you can save it back to the jpg format to keep
the size small.

A good, free imaging program, that can easily convert these files is one
called IrfanView.

IrfanView website:
http://www.irfanview.net/


--

Ronnie Vernon
Microsoft MVP
Windows Shell/User


"DanR" <> wrote in message
news:...
> When right clicking on an image file, say jpg, and choosing to rotate that
> image... a file that may have been 2MB becomes 1MB. Seems to me that the
> image is greatly degraded in quality. So I chose to not use this function.
> However it's easy to click on that choice by mistake. I see that I can
> highlight all the images in a folder and make them read-only and the
> rotate option becomes grayed out. That's a good thing.
> But I'm wondering if there is a setting that will up the compression
> quality for image rotation. It could come in handy at times when building
> a slide show.
>

There IS something called lossless JPG rotation and some programs support it
http://www.google.com/search?ie=UTF-...s+jpg+rotation


"Ronnie Vernon MVP" <> wrote in message
news:363C9CBD-FA7C-4398-9738-...
> Dan
>
> JPG images are what's called a "lossy" image format. Everything you do to
> a jpg image file will degrade the quality of the image. Making the files
> read only will protect them. The only thing that makes this image format
> popular is the extremely small size.
>
> What you can do if you do want to rotate or perform other enhancing of a
> jpg file is to first convert it to a "lossless" format such as, TIF, or
> PNG. After you make the changes, you can save it back to the jpg format to
> keep the size small.
>
> A good, free imaging program, that can easily convert these files is one
> called IrfanView.
>
> IrfanView website:
> http://www.irfanview.net/
>
>
> --
>
> Ronnie Vernon
> Microsoft MVP
> Windows Shell/User
>
>
> "DanR" <> wrote in message
> news:...
>> When right clicking on an image file, say jpg, and choosing to rotate
>> that image... a file that may have been 2MB becomes 1MB. Seems to me that
>> the image is greatly degraded in quality. So I chose to not use this
>> function. However it's easy to click on that choice by mistake. I see
>> that I can highlight all the images in a folder and make them read-only
>> and the rotate option becomes grayed out. That's a good thing.
>> But I'm wondering if there is a setting that will up the compression
>> quality for image rotation. It could come in handy at times when building
>> a slide show.
>>
>

the new irfanview supports lossless jpeg rotations if you install the plugin
pack as well, and is free of course
after you download and install it and the plugins then go to the menu>
Options> Lossless jpeg operations
see screenshot http://img300.imageshack.us/img300/9...board01lj3.jpg

"DanR" <> wrote in message
news:...
> When right clicking on an image file, say jpg, and choosing to rotate that
> image... a file that may have been 2MB becomes 1MB. Seems to me that the
> image is greatly degraded in quality. So I chose to not use this function.
> However it's easy to click on that choice by mistake. I see that I can
> highlight all the images in a folder and make them read-only and the
> rotate option becomes grayed out. That's a good thing.
> But I'm wondering if there is a setting that will up the compression
> quality for image rotation. It could come in handy at times when building
> a slide show.
>

what you say is terribly wrong.. once you save in jpg again you have lost
data...

I seldom see an MVP say something correct lately.. is this some retardation
due to vista use?

See this page MVP and learn http://www.snapfiles.com/get/rota.html

"Rotating a JPEG image usually takes 3 steps: de-compress JPEG to bitmap,
rotate bitmap, re-compress bitmap to JPEG. This re-compression process
causes additional loss of image quality. "


there are many programs like the above that can do lossless rotations and
even irfanview can if you know what you are doing..
MVPs that use vista apparently don't know.. or else they would not be using
vista the most horrible OS of all times!

the new irfanview supports lossless jpeg rotations if you install the plugin
pack as well, and is free of course
after you download and install it and the plugins then go to the menu>
Options> Lossless jpeg operations
see screenshot http://img300.imageshack.us/img300/9...board01lj3.jpg



"Ronnie Vernon MVP" <> wrote in message
news:363C9CBD-FA7C-4398-9738-...
> Dan
>
> JPG images are what's called a "lossy" image format. Everything you do to
> a jpg image file will degrade the quality of the image. Making the files
> read only will protect them. The only thing that makes this image format
> popular is the extremely small size.
>
> What you can do if you do want to rotate or perform other enhancing of a
> jpg file is to first convert it to a "lossless" format such as, TIF, or
> PNG. After you make the changes, you can save it back to the jpg format to
> keep the size small.
>
> A good, free imaging program, that can easily convert these files is one
> called IrfanView.
>
> IrfanView website:
> http://www.irfanview.net/
>
>
> --
>
> Ronnie Vernon
> Microsoft MVP
> Windows Shell/User
>
>
> "DanR" <> wrote in message
> news:...
>> When right clicking on an image file, say jpg, and choosing to rotate
>> that image... a file that may have been 2MB becomes 1MB. Seems to me that
>> the image is greatly degraded in quality. So I chose to not use this
>> function. However it's easy to click on that choice by mistake. I see
>> that I can highlight all the images in a folder and make them read-only
>> and the rotate option becomes grayed out. That's a good thing.
>> But I'm wondering if there is a setting that will up the compression
>> quality for image rotation. It could come in handy at times when building
>> a slide show.
>>
>

Rotating a compressed image (jpg) will always result in a degraded image.
This is because in order to rotate it the picture must be decompressed, then
rotated and then a degraded image (the origional jpg compression) is
degraded again in the recompression. Not much that you can do about that,
although I am supprised that 2MB went all the way to 1MB.

Michael

"DanR" <> wrote in message
news:...
> When right clicking on an image file, say jpg, and choosing to rotate that
> image... a file that may have been 2MB becomes 1MB. Seems to me that the
> image is greatly degraded in quality. So I chose to not use this function.
> However it's easy to click on that choice by mistake. I see that I can
> highlight all the images in a folder and make them read-only and the
> rotate option becomes grayed out. That's a good thing.
> But I'm wondering if there is a setting that will up the compression
> quality for image rotation. It could come in handy at times when building
> a slide show.
>

I have Photoshop on my XP partition and can easily rotate images with it.
Photoshop gives you a save-as quality choice. So I can rotate and minimize
any generation lose. Somewhere in the Vista code is a setting that
determines the jpg quality. Maybe not a setting per se but there must be
code that determines the algorithm. Even cameras usually give you at least
two choices. My newest camera knows when it shoots vertical and writes data
to the exif portion of the photo and most image software including Windows
will rotate the image properly. My older camera did not do this and I have
many hundreds of vertical images that need to be rotated for proper viewing.
It would be nice to be able to copy and rotate them in a batch. I've read
about software that will do just that but if Windows could rotate without
such a quality loss that would be nice. I bet there's a way.

"Ronnie Vernon MVP" <> wrote in message
news:363C9CBD-FA7C-4398-9738-...
> Dan
>
> JPG images are what's called a "lossy" image format. Everything you do to
> a jpg image file will degrade the quality of the image. Making the files
> read only will protect them. The only thing that makes this image format
> popular is the extremely small size.
>
> What you can do if you do want to rotate or perform other enhancing of a
> jpg file is to first convert it to a "lossless" format such as, TIF, or
> PNG. After you make the changes, you can save it back to the jpg format to
> keep the size small.
>
> A good, free imaging program, that can easily convert these files is one
> called IrfanView.
>
> IrfanView website:
> http://www.irfanview.net/
>
>
> --
>
> Ronnie Vernon
> Microsoft MVP
> Windows Shell/User
>
>
> "DanR" <> wrote in message
> news:...
>> When right clicking on an image file, say jpg, and choosing to rotate
>> that image... a file that may have been 2MB becomes 1MB. Seems to me that
>> the image is greatly degraded in quality. So I chose to not use this
>> function. However it's easy to click on that choice by mistake. I see
>> that I can highlight all the images in a folder and make them read-only
>> and the rotate option becomes grayed out. That's a good thing.
>> But I'm wondering if there is a setting that will up the compression
>> quality for image rotation. It could come in handy at times when building
>> a slide show.
>>
>

On Fri, 20 Jul 2007 21:38:02 -0500, "DanR" <>
wrote:

>I have Photoshop on my XP partition and can easily rotate images with it.
>Photoshop gives you a save-as quality choice. So I can rotate and minimize
>any generation lose. Somewhere in the Vista code is a setting that
>determines the jpg quality. Maybe not a setting per se but there must be
>code that determines the algorithm. Even cameras usually give you at least
>two choices. My newest camera knows when it shoots vertical and writes data
>to the exif portion of the photo and most image software including Windows
>will rotate the image properly. My older camera did not do this and I have
>many hundreds of vertical images that need to be rotated for proper viewing.
>It would be nice to be able to copy and rotate them in a batch. I've read
>about software that will do just that but if Windows could rotate without
>such a quality loss that would be nice. I bet there's a way.

Photoshop which I've used since version 2 is a very high quality
application, with a price tag to match ;-). It includes Image Ready
which can greatly reduce file size without a serious hit in quality.
This feature is mainly for reducing images that end up on the web so
they don't take forever to download however you can use it for other
purposes.

It is the algorithms that determine what results you end up with.

Besides working on compressed images in a lossless state if you are
planning on reducing their dimensional size making them either smaller
or large an old Photoshop trick is to do it in stages. In other words
if you want to increase the dimensions of a image by 50% instead of
trying to do it in one big step, instead do it in stages of no more
than 10% a time.
>
>"Ronnie Vernon MVP" <> wrote in message
>news:363C9CBD-FA7C-4398-9738-...
>> Dan
>>
>> JPG images are what's called a "lossy" image format. Everything you do to
>> a jpg image file will degrade the quality of the image. Making the files
>> read only will protect them. The only thing that makes this image format
>> popular is the extremely small size.
>>
>> What you can do if you do want to rotate or perform other enhancing of a
>> jpg file is to first convert it to a "lossless" format such as, TIF, or
>> PNG. After you make the changes, you can save it back to the jpg format to
>> keep the size small.
>>
>> A good, free imaging program, that can easily convert these files is one
>> called IrfanView.
>>
>> IrfanView website:
>> http://www.irfanview.net/
>>
>>
>> --
>>
>> Ronnie Vernon
>> Microsoft MVP
>> Windows Shell/User
>>
>>
>> "DanR" <> wrote in message
>> news:...
>>> When right clicking on an image file, say jpg, and choosing to rotate
>>> that image... a file that may have been 2MB becomes 1MB. Seems to me that
>>> the image is greatly degraded in quality. So I chose to not use this
>>> function. However it's easy to click on that choice by mistake. I see
>>> that I can highlight all the images in a folder and make them read-only
>>> and the rotate option becomes grayed out. That's a good thing.
>>> But I'm wondering if there is a setting that will up the compression
>>> quality for image rotation. It could come in handy at times when building
>>> a slide show.
>>>
>>

On Sat, 21 Jul 2007 05:30:42 +0300, "carl feredeck"
<> wrote:

>what you say is terribly wrong.. once you save in jpg again you have lost
>data...
>
>I seldom see an MVP say something correct lately.. is this some retardation
>due to vista use?
>
>See this page MVP and learn http://www.snapfiles.com/get/rota.html
>
> "Rotating a JPEG image usually takes 3 steps: de-compress JPEG to bitmap,
>rotate bitmap, re-compress bitmap to JPEG. This re-compression process
>causes additional loss of image quality. "

Don't confuse marketing hype with reality. Doubtless everyone has seen
all the threads saying Media Player, Movie Maker can't open such and
such video file. The reason is they are missing or can't use the de
compressor that's part of the CODEC. Same holds true with still
images. If they're compressed, then they need to be decompressed in
order to open them. What the ad copy on the above link implies is they
stop half way, which is just snake oil.

You can't un ring a bell, once any image video or still is compressed
some bits have been squeezed out, you can't put them back. In a
similar vain if you manipulate a raster based image then some pixels
are getting redistributed, discarded or added depending on what you're
trying to accomplish. It's the process itself and how well the
application can do the task that matters. The two most common methods
are Bilinear and Bicubic Interpolation. Better software uses smarter
algorithms.

Recompressing some already compressed image is a no-no. However
freezing it in it's current state by first transcoding it to a
lossless file format minimizes the re compression assuming the user
plans on re saving it in a compressed format again once he's done
working on it. Again HOW you do that, meaning what application you use
to accomplish it determines the final result.

so you too have been using vista so long your brain has been converted to
mush?

You can rotate jpeg without loss! google the keywords "lossless jpeg
rotation"



"Michael" <> wrote in message
news:%...
> Rotating a compressed image (jpg) will always result in a degraded image.
> This is because in order to rotate it the picture must be decompressed,
> then rotated and then a degraded image (the origional jpg compression) is
> degraded again in the recompression. Not much that you can do about that,
> although I am supprised that 2MB went all the way to 1MB.
>
> Michael
>
> "DanR" <> wrote in message
> news:...
>> When right clicking on an image file, say jpg, and choosing to rotate
>> that image... a file that may have been 2MB becomes 1MB. Seems to me that
>> the image is greatly degraded in quality. So I chose to not use this
>> function. However it's easy to click on that choice by mistake. I see
>> that I can highlight all the images in a folder and make them read-only
>> and the rotate option becomes grayed out. That's a good thing.
>> But I'm wondering if there is a setting that will up the compression
>> quality for image rotation. It could come in handy at times when building
>> a slide show.
>>
>