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• • April 14, 2011 at 5:27 am #59262
    Mayoor Chheda

    Member

    I understand that repeated resaving as JPEG after cropping, scaling, decreasing image size causes image degradation. However, if I crop, make minor changes to the image brightness, decrease the image size & save as PSD & later on, if required, I further retouch the PSD image & save as JPEG, would it cause too much of image degradation of would resaving as JPEG from PSD be the same in terms of image quality as the first save as JPEG from JPEG. I hope iam clear & not too jumbled up.

  • April 14, 2011 at 5:52 am #59263
    Mayoor Chheda

    Member

    I think i will make myself clear. I frequently get digital images which are too large (pixel-size). Hence, I need to crop, retouch the images & reduce the image size in Photoshop before placing in Indesign. I save the image as JPEG & place it in an Indesign document. Now sometimes the same image is to be reused, but its size needs to be further reduced according to the format. What I want to know is that should I first save the retouched image as PSD, so that while placing multiple times in Indesign in varying sizes, I can do a Save As in JPEG form the second or third time or should I use the original every time, do the changes in Photoshop, get the final size & save as JPEG. Would saving as PSD after making changes to the original image in Photoshop the first time & then later on saving as JPEG the second time cause image degradation.

  • April 14, 2011 at 8:33 am #59268
    David Blatner

    Keymaster

    Why not open the original image, crop and retouch, then save as PSD, and bring the PSD into InDesign? Then later, if you need a different size, you can resize it in Photoshop and either save, or save as a new PSD (if you need the original), and bring the PSD into InDesign. Is it necessary to save as JPEG at all?

  • April 14, 2011 at 11:25 pm #59277
    Mayoor Chheda

    Member

    Using JPEG instead of PSD is just to save space as JPEG files are less bulky as compared to PSD.Would there be a difference in the size of exported PDF on using PSD miage files as compared to JPEG image files

  • April 15, 2011 at 5:10 am #59280
    Nenad Marinkovic

    Member

    Hi mayoor

    I've just run some test. I opened InDesign and create 1 page document letter size. I placed .psd file (10 MB) and exported as pdf and size was 1.25 MB, then i used that same image but in .jpeg format (880 KB) and placed it in Indesign and exported it and size of pdf was bigger about 2.3 MB.

    Use jpeg just for web not for print, because psd is much better.

  • April 15, 2011 at 6:06 am #59283
    Mayoor Chheda

    Member

    I also tried to do a sort of a trial. I did a Save as & I saved a single image as both JPEG & PSD. placed about 30 JPEG images in 1 Indesign document & 30 PSD images in another Indesign document. Though each PSD was on an average 1.2 MB bigger than the corresponding JPEG image, the final size of the exported PDF of PSD-containing images was only 1.6 MB larger than the exported PDF of JPEG-containing images. So, PSD definitely scores over JPEG.

  • April 19, 2011 at 2:20 am #59313
    Alan Gilbertson

    Participant

    It's worth noting that unless you explicitly set something else in PDF export, your images will be jpeg-compressed on export and will be downsampled if more than 1.5x your target resolution, which at the default 300 ppi for print means that any image over 450 ppi at the size it is scaled to in the layout (the “effective resolution” in InDesign terms) will be downsampled. It's just part of how PDF export works.

    There are two schools of thought on this. One school says you should exactly size each image in Photoshop and place the resized copy in the layout. The other, more production-oriented view says place each one as a PSD and let the export-to-PDF function handle the downsampling, which in my experience works perfectly well for all but very high-end, critical print work. In either case, use the jpeg compression setting that works with your production needs, or turn off compression completely, in the PDF export dialog.

    Placing a PSD is much more productive (“Edit Original” allows round-tripping to Photoshop for any needed tweaks) than first making a jpeg or flattened tiff and placing that in the layout. It can save many hours in the course of a week. Quality degradation with jpeg is far less of an issue than most people believe, but in any case is avoided by keeping the image in a lossless format such as PSD.

  • April 19, 2011 at 2:54 am #59314
    Mayoor Chheda

    Member

    Hi Alan,

    I do not doubt your experience, but since the export-to-PDF function in Indesign has only bicubic downsampling as against bicubic sharper in Photoshop, would it make any diffence when scaling down images shot by digital cameras at high resolution (>8 MP) to print at 2-3 inches in size. Wouldnt the images be less sharper if they arent resized & downsampled in Photoshop.

  • April 19, 2011 at 2:23 pm #59329
    Alan Gilbertson

    Participant

    I'm with Deke McClelland on the subject of downsampling: bicubic sharper is best avoided because it almost always oversharpens, especially when you're making big resolution changes. Regular bicubic gives a far better result >95% of the time, and you can then tweak the sharpening with Unsharp Mask or Smart Sharpen as needed.

    The answer to your question is, “It depends.” Sharpening is one of those esoteric subjects that is highly dependent on the final output device, not simply the final resolution. What works beautifully for a good quality photo printer won't be optimum for 150-line screen on an offset press, nor for viewing on a monitor. Deke has several excellent books, several Lynda.com titles and various tutorials on deke.com that go into this in depth.

    If you're designing for high-end magazine or book publishing, you are always going to be better off treating each image individually and carefully in Photoshop. I would recommend a plug-in such as the excellent Nik sharpener, which fine tunes for specific types of final output. The rest of the time you can let InDesign's PDF export do its stuff (it's the exact same engine as Photoshop, because the actual Photoshop code was baked into InDesign long since) and get great results with far less time spent agonizing over details.

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