Downsizing TIF file while maintaining resolution

How can I decrease the image size on a TIF file while maintaining the quality resolution of the original? I have been trying this using Photoshop and need to reduce the original image size by about 80%, but the result always is a very pixelated product.

Any suggestions? Thanks in advance.

You can select different compression algorithm while saving the TIF image - either LZW or ZIP. If your original image wasn’t compressed, you might be able to reduce its size down to expected 20%. If it had already been compressed - this can be impossible.

Is it for web or print purposes?

It’s for the web. I have a TIF that is 1000px wide and about 500 high, but I need to downsize it to around 100 height for use on a page header image. It sounds like that’s not possible, eh? What type of image should I ask the client for in order to accomplish this?

Thanks so much.

So there’s dimension change too. OK
Of course, this can be done, but there’s no way for the resulting image to be of a similar quality and detail accuracy as the original one. When I scale down the images, I always apply “Unsharp Mask” filter to improve the sharpness. Also I try a few different factors when scaling down - sometimes (especially if there are regular shapes or character within the scaled image) a different scaling factor can produce significantly better results.
I assume that the TIF is only the input image format and the resulting header will be PNG or JPG.

In Photoshop while your tiff image is open go from top menu:
Image>Image Size

In pop up window check image resolution - 72 or 96 dpi is all that is required for web images. If the resolution is higher change the figure to 72 in the ‘resolution’ field and then un-tick - ‘resample’ image’ - then you can re-tick it. The image has now been changed to 72 dpi.

Next in the image dimensions field reduce the height to 100 pixels [or whatever you require] - make sure the check box called ‘constrain proportions’ remains ticked.

Then click OK.

Your image should now be the size you require and at a much reduced file size.

Then save it by going: File > Save for web

If you then select .JPEG as the output [80% or higher quality] it will further reduce the image file size via compression and give you a good quality image to publish.

Hope this helps.

You can skip this step, as it does - literally - nothing :wink:
What matters is the physical image size (in pixels) only, its resolution is unimportant in this case (web use)

Thanks to all. It appears as though I cannot change the dimensions of this TIF file without losing the integrity of the image. I will try to find another method.

The “image size” tool in photoshop lets you “constrain” the image quality when you see the little link icon. Using this while taking advantage of the “resampling” box will let you squeeze the image down in size while actually enhancing the pixels per inch. although when you put it on the web, this will all be for naught because of the medium.