Gif to jpeg re-saving

After taking quite a few pictures, taking them thru crops and various image processing, I have them saved as gif’s

Now, rediscovering the benefits of jpegs - that they take mush less memory especially for mobile) and are better with photorealism - is there a way that by changing the extension from gif to jpeg it will be done?

Or is this just a silly question, and you cannot revert? Is there an alternative?
I cannot simply recreate them all as jpegs

Changing the extension will not change the file. You will need to open it in your graphics program and do a “save as” jpeg. Depending on your program you may be able to do a batch process, and do them all at once. However, you may want to do them individually so that you can optimize compression for quality and file size for each.

You will not be able to regain any of the quality you may have lost by choosing gif in the first place, but you should be able to reduce the file size.

As a rule of thumb, it is a good idea to save the images you create as a PSDs (or other native program format) with layers intact. You can then go back and edit and do “save as” gif, jpg, png, etc. as needed. Save to disc if you have no room on your hard drive. Photoshop and Photoshop Elements have a great “save for web” function that allows you to preview and compare your images as GIF, JPG, etc at different compressions and index colors. I am not familiar with other editors, but they may have a similar option.

You can convert them but JPEG are lossy and deteriorate on repeated saves and typically store as 24-bit colour. Whereas GIF is limited to 256 colours so if you are converting GIF you will be limited to (starting from) 256 colours, which may result in plenty of pixilation artefacts with a conversion to JPG.

Thanks for the responses.

I’m on a project that has run months and months over, so I’ll probably resave them as jpegs. Comparing some of the images, it’s like 26k vs 7k so its worth it, especially since I’m trying to accomodate mobile more.

I’ll probably do them individually

…you may want to do them individually so that you can optimize compression for quality and file size for each.

Are you talking about a compression setting within Photoshop?

Karin,

Sorry, I edited the post. That removed and added here:

Also - I have a problem using Photoshop crop tool since it only lets a square dimension/rectangular-ratioed crop that I cannot specify. Unless you want to use the presets, which I don’t. So this already means going into another program just to make the crop, which in turn means a seperate save. Ridiculous.

I’m I missing something - is there a way to make a custom dimension crop in Photoshop like you can with such as basic program as Snagit?

Yes. When you save as JPEG you need to choose your compression. You can go with higher quality with a higher file size or lower quality with a lower file size. I usually use “save for web” When using full photoshop I can get 3 previews at once and the original to compare different formats and compressions and file size. Using photoshop elements I get only one preview to compare with the original. When using “save as” rather than “save for web” I believe I get a pop-up box with a compression slider, file size, and a preview checkbox to turn on and off. I use old versions of Photoshop and Photoshop Elements. (PS 6, PSE 5)

I think “save for web” also strips out meta data, but I am not sure.

I mainly use PSE v8 and I can crop to any size I like and I’m sure the “Big Brother” Photoshop will do the same.

In PSE you select the crop tool and then in the options bar there is a an “Aspect ratio” dropdown list from which you can select ‘no restriction’ or one of the presets. To the right of the dropdown there is a width and height textbox in which you can enter your own customised width and height to crop to. So cropping size is totally flexible.

In PSE8 and I assume subsequent versions, there is a checkbox in the “Save for web” option to optionally strip out the meta data.

This is Photoshop 7

I see how to enter width and height dimensions – for example entering:

Width 100 px
Hieght 300 px

windows > info gives the readout of the adjusting dimensions – where can I change this to pixels?

[LIST]
[]Is there a recommended resolution for web graphics…pixels/inch?
(generally under 250 px x 250 px)
[
]I’m not sure what is meant by stripping out meta data.
[/LIST]I see a way to scale the whole image by a percentage, say 30%
-> image size -> uncheck ‘constrain proportions’

What is ‘resample image’ - Nearest Neighbor, bilinear, bicubic?

For web graphics, pixels/inch (PPI) is essentially meaningless afaik. On a given screen a 300px x 300px image will take up the same amount of screen real estate whether the image is 100ppi or 300ppi. PPI is used mainly to size print copies of images.

The meta data is all the info about the image - exposure time, f-stop, date taken, latitude, longitude (if camera is gps enabled), ISO, metering mode, focal length, whether the flash was used etc etc etc.

Can you give an example? In PSE8 I can do a % change to the image dimensions without changing the resolution (ppi).

To scale by a % I see where resolution is metered by unchecking ‘resample image’
image size > resample image

Though I still don’t know: what is ‘resample image’ - Nearest Neighbor, bilinear, bicubic?

So meta data should probably be stripped?

So PPI doesn’t matter - should I just do save for web? Doing this I see that the quality can go up to 99% – won’t this affect file size severely?

#########
considered altogether, I think right now I will resave all photograhic gifs as jpegs, then finish out the remainder of the raw images as jpegs. In the months ahead, I should now be able to recreate/crop the original jpegs to the same size in Photoshop for redoing the resaved gif’s

My comments in green.

When “resample image” is on, pixels are created by interpolation. Nearest neighbor, bilinear, and bicubic are different methods of interpolating.

You will notice that when “resample image” is not checked, you cannot change pixel dimensions. The pixels are fixed. When you change the resolution, the document size will change, changing document size will change the resolution. When resample image is checked changing document size or resolution will change the pixel dimensions as pixels are created or discarded.

You should be able to crop to any size you like. If you have trouble with the crop tool, make a selection and choose image>crop. If it is a non-rectangular selection, it will crop to the smallest rectangle that will enclose the selection.

Definitely use “save for web”. The previews in “save for web” are actual pixel dimensions, how it will appear on a website. You can resize, choose a format, select matte color, set compression or number of index colors in the dialog box, etc. and see how these changes affect the file size and appearance. I believe in later versions of PSE than 5 you can even set a target file size and see what compression will achieve that. I have found that I can usually use a 30% compression for a jpeg without noticeably affecting image quality. If high quality images are desired, it is often preferable to have a larger, high-quality image linked to a lower-quality fast-loading image so that those who care greatly about the image can choose to suffer the extra download time.

Meta data will add to the file size and may contain information you don’t want to share, so it is usually okay to strip it. You may want to edit meta data so you could include stuff like copyright and not include location or other sensitive data.

And if you publish a photo of your house make sure you strip out the lat/long data out of the meta data, if it is recorded, otherwise you may as well publish your street address as well.

Glad you told me this.

Resampling should be avoided unless absolutely necessary because each resampling of an image degrades the image quality to some extent

But it seems I must in order to maintain the resolution.

Definitely use “save for web”.

I will.

(Could no longer edit the last post)

But I do have a question.

When saving as a PSD --is much lost if later the image is resized larger?

There is a ship load of information on resizing images (both up and down) on :google:

It will depend on how much enlarging you need and whether you do it in one hit or in increments.

In general it is best to design and manipulate your image in a size that is the largest you will think you will need (or larger) and save it full size with layers in psd format. You may later wish to adapt your banners to a larger screen size, or create a printed letter head, business card, brochure, etc. From your psd original you can use “save for web” to downsize and change format. Downsizing gives better quality than upsizing.

That said, there are many software programs and various techniques for getting good results with an upsize. Google is a good place to start.

Actually there is information about anything you might ask on Google. Lucky for us that some people come here to ask their questions. I imagine they already know they can search on a search engine.

I think I originally found sitepoint forums via a Google search on something when a forum discussion came up as one of the results.

While many people know of Google many do not know what words to use to get the results they need. So recommendations to use Google should include suggested search phrases. So, in my post I should have suggested Googling one of the following phrases:
upscaling images in photoshop
resizing in photoshop
upsizing in photoshop

This link seems pretty good: http://www.earthboundlight.com/phototips/resizing-resampling-photoshop.html It suggests bicubic as the preferred resampling choice for enlarging a photo.

if you want a jpeg with optimize quality, just use save for web feature in photoshop. and use the action feature also to expedite the process of converting gifs to jpegs in photoshop.