Jpeg lossiness

Dear All,
If all you do is rename a jpeg and save it, is there lossiness? What if you are using a batch rename process? Also, if all you do is make a copy of the original, is there lossiness in the copy?
What if you open the image in Ps CC using the new camera raw filter, make a copy of the background as a layer, convert to a smart object, make the edits then save under the original file name? I'm trying to figure out if I screwed up some very large files (e.g. 50MGs). I do have all the untouched orginals so it's not a disaster, just a lot of work that maybe went awry.
Chris

irislake wrote:
Dear All,
If all you do is rename a jpeg and save it, is there lossiness?…
If you OPEN it, then YES, no exceptions—ever.
Anytime you open a JPEG, the image is decompressed with all the losses it suffered when it was compressed originally. When you save or re-save it, the image is re-compressed once again and the loss is compounded, cumulative.
I avoid JPEGs as much as I can and generate a JPEG copy only when specifically forced to.
Obviously, if you just re-name the file label, you're not opening and re-compressing the file, so no loss there.

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JPEG, Lossy Here?

I have read the messages in the forum but I have a couple of basic questions about Photoshop Elements 4.0:
1. After opening my Organizer and editing a few photos, saving the edited photos as PSD, will the closing/exiting of Elements affect the quality of any of the JPEG photos in the Organizer since I am closing them as opposed to saving them?
2. Will moving a JPEG from one folder to another folder result in a loss of quality when I close/exit the program?
Thanks.

Ed,
Neither of your scenarios will cause any change to the original jpeg.
The damage is done only when the file has to be recompressed and that isn't happening in either case. Even copying a jpg from one folder to another doesn't do anything more than copy the already compressed bits as they are.
Bob

Image file formats gif, png, jpeg, tiff

Hi guys,
I've read a little bit about this, so I know the some basics:
gifs: lossless, transparency/animation, 256 colors
jpeg: lossy, no transparency, 16 million colors, etc.
png: lossless, 16 million colors (?), newer/better compression and transparency than gif
But I want to hear it from the designers (web and/or print, cause I do both). What format do you guys use for editing/printing photos? I've always archived and printed my photos as TIFFs, they're huge, but this way I just avoid any hassle of quality loss.
I've been reading that I should keep my photos as PNGs and then print final versions as JPEGs...is that true? How do you guys utilize the various file types?
Thanks!!!

For print I use .tiff's ( just like you ). I limt .png files to the internet. I would not convert the .png to a .jpg for print. If anything, I'd copy the original .png and convert it to a CMYK .tiff or .psd file.

Difference between jpeg settings

hi,
i want to know the purpose of jpeg quality setting in publish
settings box. what's the purpose of that setting? and whats the
difference between this setting and bitmap properties settings in
library? the livedocs on macromedia states : NOTE
JPEG Quality settings that you select in the Publish
Settings dialog box do not specify a quality setting for imported
JPEG files. You must specify a quality setting for imported JPEG
files in the Bitmap Properties dialog box.
i am a little confused because of this.
any help would be grately appreciated.
thanks
gaurav

There are many options and yes it is confusing.
Assuming Bitmap properties calls for JPEG/Lossy Compression:
1. Publish window - whatever you put in here is the default.
That number is used if nothing else overrides it.
2. Bitmap Properties setting - if you put a number in there,
it will override the default.
3. Use imported data: You imported a JPG, Flash won't mess
with it at all, it wil just export the same data.
Note that it is a bad idea to import a JPG and then
recompress it a different way for export. You get double artifacts
that way.

Some images not showing up in PDFs

Are there particular limits on what types of images can be exported to PDF and still be viewed on a mobile device? I see several PDFs where I can view the images on a desktop monitor, but not in an iPod touch. We are trying quite a few iterations of exporting images to PDF and have had no luck figuring it out.

I had this problem too. I found the answer somewhere. I don't remember where, but the answer is this:
When exporting the PDF, the iPad doesn't support JPEG 2000 standard.-- the kind used in "smallest size PDF"
Use JPEG Lossy, and voila!

Adobe Acrobat 9 query

Hi,
I have downloaded the trial of Acrobat 9 to test.
I have a folder of 3600+ greyscale jpg images which I converted to pdf using PDF Toolbox and Acrobat 7. The resulting files were 6MB over a full DVD. So I opened one of the larger files (50MB+) in Acrobat 7 and used the reduce file size function. This halved the file size.
Out of curiosity I ran all the files through Acrobat 9 using batch processing and the reduce file size function. The resulting pdf's amount to 250MB! I open some of the files and there is little difference between the large (acrobat 7) files and the smaller ones.
I also opened one of the files (50KB) and extracted the 2 pages as jpg images anly to find that each jpg was around 500KB.
How can the pdf be 50KB if the 2 images it contains are 500KB?
Also, does the standard version have the batch processing function like the Pro version?
Thanks

If there is no OCR involved, I'm inclined to wonder why you would want to contain each individual image in a PDF anyway. What functionality is PDF bringing to the table for you?
Is it simply a matter of providing a browsing mechanism? If so, wouldn't it be simpler to just use a browser application? For example:
1. Scan the images as grayscale TIFFs.
As others have explained, you are misreading your results if you think JPEG yields "better image quality" than TIFF. This is what's going on: JPEG is lossy compression. It throws away data by evaluating adjacent pixels. When it finds a range of contiguous pixels of similar value, it sets them all to the same value. Then it uses data compression to store the ranges of values.
So the reason you think JPEG is giving you "better" images is: contiguous areas of similar but different relatively light grayscale values are getting converted to white or light grays. In other words, the JPEG lossy conversion is effectively clipping and posterizing the light end of the grayscale range. The "improvement" you are seeing is just a happy accident, and is far less than the improvement you could likely gain by a better workflow that gives you better control.
To improve a batch of similar-quality grayscale scans of what should be line-art originals (that's what you have here), you need to do two things: Maximize the dynamic range, and then adjust the gamma (midpoint) to improve the contrast. In other words, you want the lightest areas to go all the way to white, the darkest areas to go all the way to black, and gray value that best describes the "edge" between black and white to go to 50%. Once you have done that, you can then convert the grayscale images to 1-bit images, in which all pixels are one of two values: White or black. The end result will be more legible and the data size will be much smaller. Then you can use lossless compression to further reduce the file size.
Depending upon the sophisication of the scanning sofware (and the undestanding of the user), all that
can be accomplished in the original scan with optimized settings. If the scanning software is crude, then the adjustment can be accomplished instead by batch-processing the images with Photoshop, applying a curve to the original grayscale TIFFs, optionally resampling, and then saving to the desired format.
2. Now that the images are optimized and reasonably-sized files, you just need to deliver them in a browsable form. That brings me back to my original question. If no OCR is involved, then how are the images identified and organized? If they are to be identified by their file names, then I wonder if Acrobat is the best mechanism, since it's not really adding any value. Sure, you can open a folder full of individual images with Acrobat, converting each to individual PDFs, or combining them into a single PDF and/or further combining them into a PDF package. Doing so, Acrobat can give you a "table of contents" by generating bookmarks for each image.
But if no OCR is involved, how is the dumb list of bookmarks any better than simply browsing the file names on disk? Wouldn't you be better off with one of many image browsing/cataloging applications? For one example, consider these simple steps in FileMaker Pro:
1. New database. Two fields: A text field named "FileName" and a container field named "Image".
2. ImportRecords>From Folder. The import dialog lets you map the image files into the container field
as a link, and the file name into the text field.
3. Bind the database as a standalone runtime application.
That's it. You're basically done. Now consider the versatility you have gained by using a proper database as a browser, instead of PDFs:
- The title field is searchable any way the user wants. Rather than just being able to do dumb linear searches, he can do more intelligent searches using logical operators. (And, Or, Not, Greater Than, Less Than, etc.)
- The found records can be sorted any way the the user wants.
- You can add additional fields to add value to the solution. For example, add one or two or a whole series of fields that you or the end user can use to categorize the records. For example, suppose part of that un-OCR-able hand-written image is a signature. The user could, at his choice and convenience while browsing the material, key the signature names into a "Signer" field. Doing so, he would be continually improving the usablilty of the solution. Eventually, he would be able to do Finds and Sorts on the signature names. And so on.
Another alternative would be to use an HTML form as the browser. That could also be delivered on the disk along with the images, would be launchable in the user's web browser, and could also be customized for additional functionality.
I'm not knocking Acrobat or PDF. But if PDF isn't really being used to any value (such as its ability to quickly generate a full-text index from OCR content), and if all you are doing is browsing a bunch of images, you might want to consider other delivery mechanisms that yield more versatile and higher-quality results than what you have so far described.
JET

Exporting to .pdf from InDesign CS5

Probably a real simple question to answer, but I'm stumped. I'm trying to export a 6 page newsletter to a .pdf format from InDesign CS5; it comes out as a 4 page document with the following orientation: The first page is fine (vertical on letter size), the 2nd & 3rd pages show up side by side (horz./letter) as does pages 4 & 5. The 6th page again is fine (vertical/letter). I never had this issue with CS4... Any suggestions? Thanks in advance, Wharton

Hi Tom,
I looked up the Spreads option in InDesign help to see what you were referring to... I see most of the options described, but the Spreads option doesn't appear to available in the "Export to Interactive PDF" pop-up box.
The options I've chosen are: Pages-All; View after Exporting; Embed Page Thumbnails; View-Default; Layout/Single Page; Presentation-Open in full screen Mode; Page transitions-None; Buttons and Media-Include all... I don't believe that the Image Handling section would be the issue, but I chose, JPEG (Lossy), Maximum quality and a resolution of 300.
Thanks

How do I permanently crop my photos (destructive edit) ?

I like how Lightroom leaves my original photo intact, and allows me to reverse all edits. However, sometimes I know I will not need to preserve the entire original file as shot. For example, I have a series of bird images where, if one can imagine the photo is divided into a 3 x 3 grid, and the bird is in the center square only. The rest of the photo is wasted space and therefore each of these images is taking up 8 times as much space on my hard drive as the image I need would. Is there a way to permanently crop the original photo, cutting out the unimportant part and leaving only my subject? Especially if some of these are RAW files, they can take up quite a bit of space.

pwmackin wrote:
buy a bigger hard drive
+1 vote.. There really is NO way to substantially reduce raw file size, so you either have to convert to non-raw format (jpeg/lossy-dng) and lose the raws, or get more space, if you want to keep them I mean. Note: the latest version of NX2 supports removing the embedded jpeg (in bulk) if that would help. That'll cut a few megabytes from every raw.

Improving readability of handwriting on scan

I scanned a printed document that had quite readable black ink handwritten comments using the "create PDF from scanner" command in Acrobat X. The comments were quite faint. I then tried scanning the same document using the same scanner using the scanner's software. I set the scan density at 600 dpi. The result was much more readable handwriting. I saved the document as a JPG and the converted it to a reduced size PDF using Acrobat X. The size of the result was a little larger, but much better quality.
Is there a way to set the scan density or otherwise improve the readability in Acrobat?

The settings that Acrobat can set (it is actually providing input to the scanner and is not directly controling things) is the settings button on the scan menu. If you use the scanner software, it is better to scan to TIFF to keep everything. If you use JPeg you may lose some of the color depth and such -- an inherent property of JPeg lossy compression. JPegs are useful if you are posting a picture to a web site, but otherwise you might find TIFF more reliable.

How do I change Transfer Syntax for DICOM images using sample Java sources?

Hi,
I tested using Note:876534.1 Java API samples. It works fine when I put the "Implicit VR Little Endian" DICOM file.
I could insert the DICOM file, also I could get the all DICOM tags correctly by SQL.
But I could not get all DICOM tags when inserted "Explicit VR Little Endian" and "JPEG Lossy" DICOM file.
Also I could not find how to change the Transfer Syntax to orddicom Java API.
How do I change following simple java source for inserting different Transfer Syntax DICOM file?
Connection conn = DriverManager.getConnection(args[0], args[1], args[2]);
System.out.println("Got database connection");
conn.setAutoCommit(false);
Statement stmt = conn.createStatement();
CallableStatement cs = null;
cs = conn.prepareCall("begin ord_dicom.setDataModel(); end; ");
cs.execute();
cs.close();
String rowInsertSQL = "insert into dicom_test (id, dcmobj) values (" + args[3] + ",ordsys.orddicom())";
stmt.execute(rowInsertSQL);
System.out.println("Inserted empty dicom object ...");
String rowSelectSQL = "select dcmobj from dicom_test where id = " + args[3] + " for update";
OracleResultSet rset = (OracleResultSet)stmt.executeQuery(rowSelectSQL);
rset.next();
OrdDicom dcmProxy = (OrdDicom)rset.getORAData("dcmobj", OrdDicom.getORADataFactory());
rset.close();
System.out.println("selected row for update...");
File testFile = new File(args[4]);
boolean success = dcmProxy.loadContent(testFile, true);
dcmProxy.setProperties();
if (success) {
String updateSQL = "update dicom_test set dcmobj=? where id=" + args[3];
OraclePreparedStatement opstmt =
(OraclePreparedStatement)conn.prepareStatement(updateSQL);
opstmt.setORAData(1, dcmProxy);
opstmt.execute();
int contentLength = dcmProxy.getContentLength();
String SOPInstanceUID = dcmProxy.getSOPInstanceUid();
System.out.println("contentLength: " + contentLength);
System.out.println("SOPInstanceUID: " + SOPInstanceUID);
opstmt.close();
Thanks,
Tatsuya
Edited by: user13490925 on 2011/01/31 1:48

It would go like this
1. TIFF + XML metadata => DICOM image file
you can use the method ord_dicom.createDicomImage(src blob, metadata xmltype, dest blob) to create the DICOM image in a blob.
2, then use the ORDDicom constructor ORDDIcom(data blob) to create an ORDDicom object
3. then use the ORDDicom processCopy method to change the image properties.
Alternatively you can change image properties on the input TIFF image (using ORDImage methods) then create the DICOM image. If you are happy with the image properties then you can skip step 3.
Edited by: rabbott on Jun 22, 2009 12:41 PM

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Acrobat is using lossy JPEG compression (quality: medium) on some images after transparent objects were flattened. Even if the images had a ZIP compression before, Acrobat will use a lossy JPEG compression. The result is a loss of quality. There are also differences in quality within a single image, cause some images are divided in parts with a ZIP compression and with a lossy JPEG compression.
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Hi Cropas!
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Is the JPEG compression option on TIF files lossy or lossless?

Is the JPEG compression option on TIF files lossy or lossless?

I accidentally used the JPEG compression on some important TIFF images. I usually use
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Hi there.
Now I am working on an app. to compare the quality between a traditional JPEG and the new JPEG2000 format.
Although I did not find the ways to encord JPEG2000 format in basic JAI, another API jai_imageio-1_0_01 does provide the way to do it.
The default parameter in the J2KImageWriteParam is for a lossless encord, the result is perfect, of course. But more importantly, I want to try the lossy ones so that I can reduce the outstream size.
The problem is here, when I just change the encoderate throught the setEncordingRate method, the result is terrible, which I am sure is a failure. I do not know why. There are many parameters I can set, does it mean I should change several at the same time, not just the encodingrate? And if I change the writeparam should I change the readparam too to decord?
My sample code is following, in it, I cpatured the screen as the source and write it into .jp2, then read it out to show.
Please help me, thanks a lot.
import java.awt.*;
import java.awt.image.*;
import java.awt.event.*;
import java.io.*;
import javax.media.jai.JAI;
import com.sun.media.imageio.plugins.jpeg2000.*;
import javax.imageio.stream.*;
import javax.imageio.ImageIO;
import com.sun.media.imageio.plugins.jpeg2000.J2KImageWriteParam;
import javax.imageio.*;
import javax.media.jai.operator.AWTImageDescriptor;
import javax.media.jai.RenderedOp;
class screen18 extends Frame{
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     Rectangle screenSize;
     BufferedImage bi= new BufferedImage(1024, 768, BufferedImage.TYPE_INT_ARGB);
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          System.exit(0);
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          s.setSize(1024,768);
          s.show();
}

Hi Wayne,
if you take a JPEG image from your file system as a source instead of the Robot, the lossy encoding works:
sh = ImageIO.read((new File("C:\\Images\\Bild0.jpg")));instead of
sh = (new Robot()).createScreenCapture(screenSize);and later...
paramJ2K.setLossless(false);
paramJ2K.setFilter("w9x7");
paramJ2K.setEncodingRate(Double.MAX_VALUE * 0.5);//key pointBest regards
Dominic

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Image
Format                                     : JPEG
Width                                        : 1 306 pixels
Height                                       : 979 pixels
Color space                             : YUV
Bit depth                                   : 8 bits
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Stream size                              : 2.83 MiB (100%)

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I guess one cannot import cannot import a CMYK image in Premiere at all.
When I inspected the image in Media Info it ID'd it as a YUV and so I assumed that the imagwe was converted for use in a video that they'd created sometime in the past.
Is there even such a format as YUV for still images? Probably not even though Media Info ID'd it as such.
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Best file type; JPEG, TIFF, PNG etc

I'm using Iphoto 5 (can't decide to buy 06 or buy new Imac - still thinking on that ...) and wonder what is the best file type to use. When importing pictures from my camera they are jpeg's (haven't tried raw setting yet)- from my scanner I use TIFF. It appears the TIFF files are a lot larger - 20 to 50mb compared to the jpegs 1 to 5mb. I've opened the TIFF files in preview and save as JPEG to reduce the size and also scanned using JPEG format - I don't see any advanatge to the larger tiff files and the smaller jpegs are easier manipulated - am I'm missing something?

Hi Arlington,
There is an important difference between JPG and TIFF:
JPG uses a lossy compression!!!
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That's the difference - if you want to edit your pictures (e.g. in Photoshop) and quality is your first priority then go with TIFF. If you just download the pictures from your digital camera and store them then JPEG is your best choice.
HTH,
Koinseb

Jpeg lossiness

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