Hi JBVicc,
I can't answer your query so apologies. However, a couple of members have tried, albeit unsuccessfully, and knowing panther, I am sure he did read your original post. It's perhaps too obvious to say this, but I will; a wee note along the lines of, "Thanks for responding, but that hasn't helped me", is a decent way to respond.
I have to admit that I haven't encountered your problem very often. On cb+, we have some big files, annuals etc, but they do have high page counts.
I scan at 300 dpi, and find a 32 page comic doesn't come out too big, but size will increase if you start manipulating the pages. This may be completely irrelevant.
Let's see if anyone else responds.
Paw.
Yes, I very much appreciate the replies I've received to my question up to this point, but when "The Australian Panther" says "It's unclear to most of us, why the size of the individual files is a problem", I have two issues with that kind of reply:
1. Always remember that nobody can speak for anybody else in a forum ("to most of us"). That's an old axiom on Usenet (and I know that this forum isn't part of Usenet and is not a newsgroup) and saying something like that in almost any newsgroup is a good way to quickly get chastised by the other participants.
2. My reason for having a problem with file size is entirely my business and has nothing to do with my question about which program or method others are using to batch reduce a bunch of .cbX files' sizes.
However since #2 seems to be a stumbling block for other people, I will go ahead and explain:
A. I have limited storage capacity on the drive I'm using to archive my comic collection and don't want to have to go through the difficulty of ordering and installing yet another one.
B. Defragging or running an anti-malware check on a collection of large files takes longer than doing either on a collection of smaller files.
And I don't want to discuss my reason for having a "problem with file size" any further. Doing so diverts from the original question I have and is a complete waste of time.
So thanks for replying, but I don't think anybody who has done so up to this point understands what I'm saying. So I will start from scratch again:
Let's say a guy has several comic book files (*.cbz and *.cbr are the most common types, hereafter referred to jointly as .cbX files) and those files are all containing say 36 pages within them. The .cbX files within his collection are very large and he would like to conserve space on his drive by somehow reducing the file sizes of the .cbX files within his collection. He wants to find a program that will reduce the file sizes of the .cbX files, but a bunch of them at a time. How can this be done?
A .cbX file is simply either a .zip file or a .rar file with the file name extension changed from .zip to .cbz or from .rar to .cbr. That's the only difference between a .cbX file and a compressed (either .zip or .rar) file.
A .cbX file contains within it several image files usually in the .jpg format, but they can also be .png or some other image file type (I've so far only seen .jpg images in the .cbX files I've opened.) To view a list of the image files within a .cbX file, you can use a program such as 7-zip (
https://www.7-zip.org/) to "Open" the .cbX file. If you have 7-zip configured properly, the list will show you the actual image file size as well as the "compressed" (by 7-zip) file size. However, you will immediately notice that the image's actual, unarchived file size is the same or almost the same as the "compressed" file size if the image format is .jpg. This is because .jpg images are a already compressed versions of say, .bmp or .tiff files, the latter two of which are usually quite large in size. This is mainly why the .jpg image format came about in fact. And because they're already compressed, most archival programs like 7-zip or Winrar or Winzip don't bother trying to compress them further when you include .jpg or .png files in a collection of archived files within a .zip or .rar file since it won't make an appreciable difference to try to do so anyway.
However, if the images within a .cbX file were scanned at too high a resolution resulting in files that are too large a height in pixels height by width in pixels, they can be "resampled" down to pixels in height and widths. Note that an image that is say 1000 pixels wide by 1600 pixels high is going to have the same file size regardless of how many pixels per inch resolution it is set to display at. That's because display resolution only determines the displayed size of the image (unless the program being used to display the image compensates for display resolution, as most comic book reader programs do.) If you don't understand the difference between scanning resolution and display resolution, then go here:
http://www.modernimaging.com/resolution.htmRegardless, about the only practical way to reduce the file size of a .cbX file is to extract all the images within it, then resample those images down to a smaller height and width in pixels. To do this safely, most image editing programs allow you to change either the size of the height or the width and then the other will be adjusted accordingly if you make sure that you preserve the "aspect ratio". There's usually a setting somewhere in such programs to allow you to do exactly that. Once all the images are reduced in total pixels height and total pixels width, they'll have an accordingly smaller individual image file size. Once you put all the image files back into a .cbz (.zip) or .cbr (.rar) file, that resulting .cbX file will naturally also have a smaller file size than the original.
However, if you have a BUNCH of .cbX files that are too large, it's far too tedious to have to do this process one comic book (.cbX file) at a time. Instead, you want a program which will automatically do this to several comic book .cbX files in a batch at a time. In other words, yes, the program should be able to batch process the image files within a .cbX file, but it should do this as a subset of the overall process of batch processing a bunch of .cbX files themselves.
If anybody doesn't understand this last paragraph, please feel free to ask me for further clarification. It's key to understanding the question I'm asking the group.
In my original post, I mentioned the three programs I've found so far which supposedly can do exactly this. Each of those programs has some kind of problem or another and I mentioned that in my OP. My search for a working (freeware) program has taken literally hours, so I feel that I've done due diligence. I had thought that I'd made that obvious enough, but perhaps my saying so here will make that I have done so more more clear. Accordingly, and as part of my search, I have created an account here and am asking if anybody else has found another way to batch reduce .cbX (as opposed to just batch reducing the image files within them) file sizes.
TIA for any help you can provide.
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Topic: Reducing .cbz and .cbr file sizes. (Read 8403 times)
