Some of my media files (photos in particular) are large because I scanned them in high resolution. I would like to reduce the file size, but not compromise quality of the photo. Looking for some ideas on what most people use for resolution for your RM photos.
The simplest way to reduce the file size without loosing quality is to change the dimensions of the image. There are many software tools you can use and also free online tools.
I know how to reduce the files, I want to know recommended size and resolution of the photo.
It is subjective (based on the output to be generated) how to choose s_i_z_e . One or more little square or rectangular portrait(s) nestled on letter/legal/A5 sheet with report text will likely never need to be larger than that its sheet’s dimension. Chart backgrounds, full-page images, and anything that will be upscaled in size would tend to be larger. Here’s a photographer’s explanation, in general terms.
I will give a for instance. I have a 4x6 photo that is 12MB when it could probably be 500KB. I scanned it at a high resolution thinking I would try to make it better in PhotoShop, but never did. Most photos I take with my camera are 2 to 3 MB. Photos for viewing on a PC do not need to be that large to have good quality. I suppose I will just have to decide on a resolution myself. I do look forward to read link you suggested. That may help me decide.
A great deal depends on what you mean by “compromise quality of the photo”. There is a sense in which you can’t reduce the size of a photo very much without compromising its quality. You are probably going to have to use lossless JPG if you want the absolute maximum of quality. I have no experience with lossless JPG photos.
I have a close friend who is a commercial artist who has a fancy scanner whereupon he scans old photos at some ridiculous resolution of something like 20,000 DPI.He claims to be able to see individual grains of silver in old black and white photos. I don’t know how big such scans are, but I’m sure they are humongous.
I personally don’t see any need for that level of resolution. I usually scan old photos at 200 to 300 to 400 DPI, depending on the photo. Having scanned a photo thusly, I don’t further compress it or try to reduce its size.
One thing I often do with old photos is to edit them with a photo editor where I add white space outside the original image. Then in the white space I add text to annotate the photo. This is sort of like writing on the back of the photo except it’s writing on the front. By adding white space my annotation doesn’t cover up anything in the original photo.
When I add annotation in this manner, I use PNG format instead of JPG format. PNG is a lossless format. Scanning a photo in PNG at the same resolution as JPG, the PNG files are 50% bigger to 2 or 3 times bigger (not hundreds of times bigger!). But it’s worth it to me to be able to add the annotation without losing any quality over what might have been lost in the original scan.
Here is an example of an annotated photo. It was scanned originally at 300 DPI. The file size is 834 KB. The JPG was 259 KB.
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Resolution is dependent on your views. Typically, a printed photo only has about 200-400 ppi, so scanning anything above 600 is just generating more pixels that’s not needed. Just remember that “normally” people do not pixel peep (aka zoom in to 300% or more). The easiest way to reduce your file size is to change the ppi to 600. You can test it on a copy of a photo to see if you can tell the difference at a nominal seated position.
I always say that if you plan to restore a photo, scan it raw and save as tiff. If you want the scanner or your scanning software to do all restoration and it looks fine to you, save as jpg.
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Jerry, I like how you’ve cropped outside the edges of the print to preserve that property of the artifact. And I dressed just like you at that age (and still do much of the time, without rolling up the pant legs!).
If I scan what I consider an important photo, especially an old black and white print that’s really crisp and clear, I scan at a high resolution (maybe 1000 dpi) and save it as a png format file. It’s just like TIF in that its lossless, but it does get compressed to some extent. I have a special archive of these “important” scans. If I ever need to zoom in and see what was written on something in the photo, using this image is my best chance to read it.
My hope is to preserve this scan with backups and then not worry about preserving the original paper. (although I still do try)
I’ll then take the png file and save a copy in jpg for normal use, such as in RM.
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That is a good process. Wish I would have ask this question some years ago before I scanned all the old family photos. Appreciate all the good input.
