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Resize image without losing quality

Bob36180 Posted messages 335 Status Member -  
Maxime_Photoshop Posted messages 53 Status Member -
Hello everyone!!

Everything is in the title!! I'm looking to resize an image without losing quality...
I've tried methods suggested on the internet but without success!!

Thanks in advance for your responses.

Configuration: Windows / Chrome 81.0.4044.113

8 answers

  1.
    Alex- Posted messages 3004 Registration date   Status Member Last intervention   964
     
    Hi,
    no, nothing is in the title:
    starting image dimensions and resolution and desired dimensions and/or resolution?
    No info, no help...
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  2. Bob36180 Posted messages 335 Status Member 17
     
    Sorry, I thought the problem was simple enough, but I actually forgot to specify that I wanted to reduce the size of an image without losing quality, specifically changing it from 1000x1000 to 293x293...
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    1. Alex- Posted messages 3004 Registration date   Status Member Last intervention   964
       
      Since it is not specified, I will assume that the resolution remains the same. In that case, reducing the dimensions has no impact on the image quality.
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  3. Maxime_Photoshop Posted messages 53 Status Member 1
     
    Hello!
    So I'm going to give several answers because I have trouble fully understanding the problem.
    In Photoshop, we work with pixels (unlike Illustrator, for example), and so if you zoom in, you inevitably lose quality. The first issue arises: when you reduce the size of a layer and confirm, the pixels of the reduced image will be memorized and the previous image will be destroyed. When you resize the image back up, it will be of poor quality because you tried to enlarge a small image.
    The way to avoid this issue: right-click on the layer: convert to smart object. This way, the original image will be saved even if you reduce the size. So when you resize it back up, it will retain its original quality. If you want to draw on it (for example), you can right-click / rasterize the layer. This is not possible on a smart object. Once you've finished modifying the layer, if you want to reduce the size, don’t forget to convert it back to a smart object again.

    The second problem: you want to import, for example, 4 images with a resolution of 1920*1080 pixels that you want to place side by side like this:

    oo
    oo

    If you open all four, resize them to fit, then export the image, when you open it, the entire image will be 1920*1080 in size, so if you zoom in on one of the images, it will only have 960*240 left (you divide by 2) and thus it will be blurry.
    The solution: create a new document sized 3840 * 2160 (you multiply by 2). Import your images that will be the right size. Now, if you export and zoom in, each image will still have 1920*1080 pixels for itself.

    There's a third case: you have a small image that you want larger, but I don't think that's your problem, let me know if that's the case.
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    1. Alex- Posted messages 3004 Registration date   Status Member Last intervention   964
       
      He explained what he wanted: to resize an image from 1000x1000 to 293x293.
      So there's no problem and even less reason to discuss it...
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      1. Maxime_Photoshop Posted messages 53 Status Member 1 > Alex- Posted messages 3004 Registration date   Status Member Last intervention  
         
        Let's think about it, do we create an account on a forum when there isn't a problem? There is either a misunderstanding of how Photoshop works, or an issue with one of the problems I've proposed. I've only been here for a short time and I've already encountered 3 people with this problem (only one of them actually went back to check their question, which is quite frustrating when you take the time to write).
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      2. Maxime_Photoshop Posted messages 53 Status Member 1 > Alex- Posted messages 3004 Registration date   Status Member Last intervention  
         
        I think this is the second issue I mentioned: wanting to make a photo smaller but still being able to zoom in on it after export without losing quality.
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    2. anonyme
       
      To maintain the same quality without losing quality is simple. Let’s say image 1 is 100 cm by 50 cm and is 100 MB in file size in Photoshop. When you decrease the size, adjust the DPI to keep that 100 MB, and you won’t lose anything.
      You reduce the size to 10 cm x 5 cm, but thanks to the DPI resolution, you set it to maintain that 100 MB file size.
      For example, the photo is 100 cm by 50 cm at 72 DPI with a file size of 100 MB.
      If you reduce the image size to 10 cm by 5 cm, the 100 MB will decrease, so set the DPI to 400 or more to keep that 100 MB file size, and then save the photo. If one day you want to revert to 100 cm by 50 cm, you will need to set the DPI back to 72 to maintain that 100 MB file size.
      It’s when you save that this adjustment window opens where you can act on height, width, and DPI.
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  4. trorigolo
     
    Hello,
    "resizing an image without losing quality... "
    it's like the multiplication of loaves, only God can do that.
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    1. anonyme
       
      pffff there will always be incompetent people to show their ignorance
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    2. anonyme
       
      Pro at Photoshop for 30 years, at least I know how to use it.
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  6. Maxime_Photoshop Posted messages 53 Status Member 1
     
    Read my comment, it's not stupid, there can be multiple meanings to his request.
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  7. contrariness Posted messages 17905 Registration date   Status Member Last intervention   6 244
     
    What you want to do is not possible because you are changing the resolution of your image from 1000x1000 px to 293x293 px. This involves resampling.

    But if we do not resample, we can change the image size by its dimensions without losing quality. For example:
    If your image is 10x10 cm at a resolution of 150 dpi, changing its size to 5x5 cm will increase its resolution to 300 dpi.

    So we double the resolution, we have no loss, and we keep the same display definition. Now, depending on the use of the image, there are solutions. For example, for the web, we can use a larger image at a low resolution that we reduce in size (HTML code) to achieve better display definition.
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  8. Bob36180 Posted messages 335 Status Member 17
     
    Well... excuse me, I was quite rushed when I asked my question and I didn't take the time to properly describe my problem.

    So it is indeed the second problem that @Maxime_Photoshop mentioned! That is to say, "to reduce a photo in size but still be able to zoom in on it after exporting without losing quality."

    Thank you all for your answers, I will apply your methods to my project!!
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    1. Maxime_Photoshop Posted messages 53 Status Member 1
       
      Impeccable! Let us know if everything is fine.
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    2. anonyme
       
      I provided a solution earlier and it's very simple with Photoshop.
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  9. Maxime_Photoshop Posted messages 53 Status Member 1
     
    It's not a "size" problem but simply a resolution issue. It's not a technical problem, just a question we also had when we started. Basically, he wants to be able to reduce the size of an image by let's say 50%, export it, and then when he looks at the export, be able to zoom in on the photo and have the original quality.
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