Place guidelines by percentages, and not absolute pixel locations. Then make selections based on your guidelines.
Understand, though, that if the percentage of one of the physical dimensions doesn’t cause a guideline to fall directly on the border between 2 adjacent pixels, your marquee selection won’t match up exactly with the guidelines.
Example: you have a full image size of 250px wide X 150px high, your guidelines can be placed at exact proper percentages (20% and 33.3333% respectively.) With these guideline placements you can then use them to snap 50px X 50px marquees exactly in place to divide the image up into 15 perfect squares.
BUT!!! If your image can’t be evenly divided by 5 & 3, respectivelywith no remainder in the pixel count, you won’t be able to do it.
You can’t split pixels in a raster image.
Soooo….make sure the image you begin with is of a size that can be divided into integer-only values, with no remainders or places to the right of the decimal point.
Does that make sense to you?
Gary,
Not knowing what your intent is for the split up image pieces, I’ll just offer that one very easy approach to doing this is to use the Slice feature in Image Ready. The limitation is that the slices are generated and saved as part of your Optimized output, for reassembly in a table, via an HTML page. This means your output image format is restricted to web-compatible formats (JPEG, GIF, etc.) rather than perhaps retaining a PSD or TIF format. If that’s an acceptable solution, then the Divide Slices command allows you to specify how many vertical and horizontal slices you wish to make, disregarding any concern for percentage or pixel specifications.
Regards,
Daryl
