Don, the 2nd son Loc: Crowded Florida

This image size issue has always confounded me:
Megabytes
Megabyte (MB) is a unit of transferred or stored digital information, which is extensively used in information and computer technology. In SI, one megabyte is equal to 1,000,000 bytes. At the same time, practically 1 megabyte is used as 220 B, which means 1,048,576 bytes. Nowadays, the amount of information measured by megabytes is used for representing the size of a typical MP3 file, the size of a JPEG image, and so on.

A friend asked for an image of less than 5mb. So I followed instructions and changed the MB size of this image (dew _9483) from 2,462 kb which equals 2.40mb in binary form as shown in "properties.". When I open it in Adobe PS it says it is 6.32mb in binary!? When I reduce it to 4.82mb in PS the result as shown in "properties" = 2,075kb which converts to 2.03mb in binary form. So I don't understand how size in "properties" = 2.03mb but Adobe PS says the size is 4.82mb!? Obviously I'm Ai challenged!

(Download)

Ysarex Loc: St. Louis

Compression. In properties you're seeing the size stored on disk and that includes compression. Open in Photoshop you're seeing the size uncompressed. Photoshop uncompresses the image to display it.

Don, the 2nd son Loc: Crowded Florida

Oh, that makes sense. That's why they require jpgs instead of tifs for email and such. That suggests that the images on my hard drive (jpgs) are compressed for storage. Good reason to store my important images as tif.

Thnaks that helps.

bleirer

You made me google. I ended up not caring. I don't think there is an SI unit for bytes. They use mole. I think kB is 10 to the 3rd, but kiB is 2 to the 20th. But I am also tech challenged. They seem to mix and match. Whats a million among friends? A hard drive is kiB but an image is kB. Ram is probably kiB.

Don, the 2nd son Loc: Crowded Florida

BebuLamar

The size reported by PS is right on. It's 3 bytes per pixel.

Canisdirus

An easy fix is to download Irfanview viewer...it's free.
When you open up 'save as' ... there is a way to tell Irfanview the limit.
Some websites won't allow me to upload images larger than 30MP... and I routinely have 45 and 50MP images.
No worries...just plug in 29MP in Irfanview...save to desktop...and voila ...uploads with no problems.

lamiaceae Loc: San Luis Obispo County, CA

Nice picture by-the-way.

1kb = 1024 bytes. Multiples of 2 not 10. Keep going up to TBs and the discrepancy grows. HDD and SSD manufacturers have always fudged it.

Want to get more confused? Consider bits to bytes. I wonder, is it still 8 bits to the byte. Since computers and everything related are no longer 8 bit but usually 64 bit. Such crazy fun. Don't quote me but Ps is correct when the file is open. And I think Windows reports the compressed size for compressed files like JPGs.

Strodav Loc: Houston, Tx

Agree. It's all done in binary where 1 byte = 8 bits where a bit is the smallest unit of information in a computer and is either on or off. A kilobyte = 2^10 = 1024 bytes (2 to the 10th power) and a megabyte = 2^20 = 1048576 bytes.

Don, the 2nd son Loc: Crowded Florida

Thank you.

Don, the 2nd son Loc: Crowded Florida

Thank you, I'll download that.

Don, the 2nd son Loc: Crowded Florida

Don, the 2nd son Loc: Crowded Florida