I am an Adobe user since 1994. Recently, I am having a problem regarding document/image size issues which I have never faced earlier or I have never recognized it. I already talked with two college professors who are specially teaching on Adobe Softwares if they can help me out of this problem but unfortunately they failed to resolved the issues and they never recognized this issue too.
Actually, I have opened a document sized 45mm x 45mm with 300 ppi for one of my client. After opened the document, when I am checking the image size under the "Image" menu, it's showing 44.96 x 44.96 instead of 45 x 45mm, and for this reason, I failed to upload that image to a perticular website as they were asking for the file size 45 x 45mm. Can anyone tell me why the image size is showing different then the size I opened the document.
Thanks for the report on this, and you're right, this math can be confusing. @davescm is correct here that since images in Photoshop are comprised of pixels (raster), at this resolution of 300 dpi, the image at ~45mm will be 531x531 pixels.
If you were to increase the WxH by one pixel to 532x532 pixels at 300dpi, the resulting measurement would be 45.04mm x 45.04mm.
In order to realize 45x45mm at 300dpi, we would require a partial pixel since at 300dpi a single pixel i