I want to know how to resize a photo without loosing quality....... in the image resize box the is a check box that says maintain file size ......what does that do .
I have tried to resize using it and the file stays the same as the original.
Thanks for any advice
Mike
mike Rawlinson said:in the image resize box the is a check box that says maintain file size
It preserves the number of pixels in the image and just changes the dpi setting in the header. For example, a 1000x1000 pixel image at 300 dpi resized to 150dpi will become twice its original display size, at half the resolution, with no pixels being added, discarded or mutilated -- ie, still at 1000x1000 pixels.
The reason it seems to "stay the same" is because often, the program you are using to display it ignores the dpi instruction in the header and just renders those pixels according to other rules. For instance, on the web, there will often be a "height=xxx; width=yyy" setting that forces display to a particular size, regardless of the number of pixels or dpi of the image. Other programs may limit the size of an image so that it "fits" the screen size, or display at the resolution of the monitor. In all these cases, the change you made will have no effect.
So, what you are doing retains all the original pixels and therefore "loses no quality" but is often a pointless exercise.
The problem i have Harry is when I open up a photo its 72dpi and around 1,200 x 812 mm ....... so now i want to resample it to a 288 x 150 ....... if i just alter the size the dpi stay the same........if I alter the size and check the "maintain original size" the dpi goes up to 384........ so I save it and close the photo but when I open it up again its the same size as when i started .........why dont it stay resampled to 384dpi.
I want to print at its best .......dont want it for web.
Thanks for your reply Harry
So long as you are re-opening the image in photopaint, your resolution change ought to be preserved.
In the test I've just done -- with X4, not X5 -- I changed an image from 96 dpi to 300dpi (with preserve image size selected) and when reopening it it is still as 300dpi. So it looks as if X5 is behaving differently and wrongly.
However, I've come across dialogues like this where the order in which you do things is important. You can sometimes get a clue from the display. If you change the dpi with maintain size off, the width and height should change too. If you then turn on maintain size, it should go back and restore the original size (keeping your new dpi). That's what X4 does, but if X5 doesn't. then perhaps you need to turn maintain size on before changing the dpi setting.
Another thought ... what file type are you working with? Perhaps there are specific file types which exhibit the problem.