question on download size dimensions
joejoe
Registered Users Posts: 19 Big grins
Hi,
Suppose my original image has dimensions of 3000 x 2000 pixels.
If I said 1 Mpix downloads would be about 1200 x 800 pixels and 4 Mpix downloads would be about 2450 x 1633 pixels, would I be correct?
If I'm wrong, what would the approximate size be for the 1 and 4 MPix downloads based on the original image size given?
For the future, how are the smaller sizes calculated anyway? If my originals were larger at some point, is there a calculation I can use to figure this out or do I just find dimensions which are proportional to the original and equal about 1 (or 4) megapixels?
Thanks
Suppose my original image has dimensions of 3000 x 2000 pixels.
If I said 1 Mpix downloads would be about 1200 x 800 pixels and 4 Mpix downloads would be about 2450 x 1633 pixels, would I be correct?
If I'm wrong, what would the approximate size be for the 1 and 4 MPix downloads based on the original image size given?
For the future, how are the smaller sizes calculated anyway? If my originals were larger at some point, is there a calculation I can use to figure this out or do I just find dimensions which are proportional to the original and equal about 1 (or 4) megapixels?
Thanks
0
Comments
When you rescale to a smaller size, you multiply each of the Width and Height by the SQUARE ROOT of the size ratio.
For example, 1-million pixel file has (1/6) the number of pixels. The Square root of 1/6 is 0.408. The new file would therefore by (3000x0.408) by (2000x0.408), ie 1224x816.
A 2-million pixel file would be (3000 x sqrt(1/3) ) by (2000 x sqrt(1/3)) = 1732x1155
To find out how many megapixels an image is, just multiply the pixel dimensions together and divide by 1 million. For example, an 816x1224 image is 998,784 pixels. Divide that by 1 million and you get .998784 (just under 1 Megapixel). If it is twice as wide and tall, or an 1632x2448 image, it will be nearly 4 Megapixels.
Portfolio • Workshops • Facebook • Twitter