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R
Ravingdork
Participant
September 27, 2018
Answered

How do you reduce file size of bulk images, while keeping original file type and naming?

  • September 27, 2018
  • 2 replies
  • 10290 views

My company has a website with over 1500 images of various file types and sizes. I've been asked to reduce their file size so that the website can run much more smoothly (many of the images are much larger than they need to be). I figured that making a batch process of some kind in Photoshop might be the best way to go about it, with so many files.

However, the more I delve into the process, the more it seems it wants to change the file names, or convert all of the various image types to a single file type.

How would I/should I build a batch process that takes the images from folder A, optimizes their file size for web, then saves them to folder B with the exact same naming conventions, folder structure, and file type?

    This topic has been closed for replies.
    Correct answer D Fosse

    HOW ARE THEY LARGER!? I processed only those that were over 100 kb and the majority of them increased in size. There must be something wrong with my action settings. How is setting them to 72dpi making the file sizes larger?


    Ravingdork, you're going about this the wrong way. This is for a website, right? For web (screen viewing) the ppi number is irrelevant, it doesn't apply. Ppi is a print parameter. For web use, the ppi metadata are normally stripped from the file altogether.

    You need to look at pixel sizes. That's the only thing that matters here. Unless you're actually reducing pixel dimensions, the file remains the same.

    For jpegs there is also the compression rate. This doesn't touch the pixel sizes, but is a data compression algorithm.

    You should be aware that resaving a jpeg at the same compression level will usually increase file size slightly. Jpeg compression is much more effective on flat areas than fine detail. But the compression introduces artifacts that are for all practical purposes added detail. Hence, larger file.

    2 replies

    JJMack
    Community Expert
    JJMackCommunity Expert
    Community Expert
    September 27, 2018

    The bulk of data in all image file type is Pixel data.  How well the image encoder compress the pixel data  the smaller the file will be.   Image with great fine details will not compress as was as a  picture of a white wall.    So the biggest factors contributing to file size are.

    The Number of Pixels you have for an image.

    The Number of Channels of Pixel data image mode - bitmap, Grayscale, RGB, CMYK

    The number of bits per pixels per channel  1bit 8bit, 16bit 32bit

    Image Content details.

    Encoding and data compression methods.

    Some File type encoding sacrifices Image quality to produce smaller files.

    The easiest way to produce smaller file is to resample you image down in size reduce the number of pixels you have for an image. Give up some image quality.

    Web sites image are Normally resample way down in  So they do not need to be scale done in size to fit in a web page via html and also have their metadata striped so small file will be saved so the will transfer quickly over the network.  So the First to do is make sure you web image  have been sized to fit into web pages and their meta data has been stripped,  With Jpeg images  you can give up more image quality  by reducing the image quality setting used when you save for web.  The are some third Party Plug-in available for saving PNG files that claim to save smaller file them Adobe does. For Animated Gif you can reduce the number of frames. Sane PNG ins 8bit color the is no need for 16bit color on the web.  Jpeg only supports 8bit color.

    JJMack
    Muqqarib Hassan
    Muqqarib Hassan
    Inspiring
    September 27, 2018

    Hi,

    1:- Go to file

    2:- Select Script

    3:- Then Select Image Processor

    4:- then choose your folder which images you want to resize for web

    5:- then choose your required setting for web image size and then run it.

      R
      RavingdorkAuthor
      Participant
      September 27, 2018

      Thank you for the clean and easy breakdown, but I've tried that already. It converts all of the images to a single file type. I need to be able to maintain their original file types.

      R
      RavingdorkAuthor
      Participant
      September 27, 2018

      opps. I knows these two methods that i told you.

      Best of luck!


      HOW ARE THEY LARGER!? I processed only those that were over 100 kb and the majority of them increased in size. There must be something wrong with my action settings. How is setting them to 72dpi making the file sizes larger?

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