How to auto generate Retina and Non-retina images from psd - photoshop

I have a PSD file for my App Interface that was designed for Retina iPhones with a resolution of 640 x 1136. I want to add support for non-retina devices and and add all image assets with both a retina and non-retina version. I find the process of resizing every ui component on photoshop individually very tedious. Does anyone know how I can auto-generate Non-Retina images from the Retina images I have already exported? Thanks

If you have Photoshop CC, you can use Adobe Generator (especially nice when paired with Russell Brown’s free Layer Namer extension). Adobe Generator automatically exports any layers whose names end with .png, and can also export multiple resolutions.
There are also some great posts on this topic by Marc Edwards on the Bjango blog; specifically: Exporting from Photoshop. His articles deal with creating a slice sheet that you export semi-automatically with scripts.
I have used both of these workflows in production. Each has its quirks, but they can both probably be made to do what you’re after.
A tip: I prefer to design at 1x and then scale up. If you design and scale down, you might make an asset an odd number of pixels wide, which could look bad when scaled down. But many graphic designers I've worked with prefer to design at 2x.

For images i am using Resizer .Quite nice and fast application.

If you're able to work from the original .psd then the free SuperExport Photoshop script might be of use. It allows you to export flattened crops (not just entire layers) at multiple resolutions by careful naming of groups and layers. Documentation is here, and an updated version that also supports 3x is here (I'm the author of the - small - 3x modification).
The benefits, as pointed out in the docs, of using the original .psd are that you can see your design in context while selectively (and easily) regenerating assets with a single click.

Related

What is the highest quality export for Spotfire visualizations?

I have a question regarding high quality exports from spotfire to PDF.
I read on Spotfire support page that to obtain highest quality exports for visualizations you should select vectors (instead of rastar). They still provide better quality than rastar graphics with maximum quality (5 out of 5). However, when I export these images to PDF, the quality is relatively low. Is there a way I can increase the quality? Would it help to select e.g. PPT exports? I think manual screenshots are still better in quality, but more timeconsuming. We are looking for end-user friendly interface.
Furthermore, if your table is longer and you use slider, what is the recommended way of exporting such a graphic?
Thanks a lot.
raster graphics are generally lower quality. jpeg, for example, is a raster format, where each pixel in the image is coded to a specific color; if you resize the image, it becomes blurry or loses detail.
vector format defines points, lines, and shapes that make up an image. when you scale the image up or down, there is no guesswork trying to blend pixels -- instead the points are recalculated to whatever size. for example, fonts are usually vector format, which is what allows them to be scaled up or down to any size.
the quality of the vector image may be low due to the zoom settings on your PDF viewer (although the image can be scaled to any size, your screen still relies on pixels to display it), but it is the most possible detail. if you zoom in you will probably see an increase in quality.
manual screenshots probably look "best" because there is no scaling or resizing involved. you can export to PNG (raster) image format to get the same effect.
you will not see an increase in quality by exporting to Powerpoint. either you will export it as a raster image to a PPT slide (default settings) or you will export it as a vector using the "As Editable Image" checkbox (which allows you to modify the image in PPT).
what is your end goal? Spotfire is best suited for viewing in the Desktop or Web Player applications, otherwise you lose a lot of features like interactivity, (potentially) live date. if you have to make a lot of exports maybe it is easier to simply provide a link to the analysis?
to your final question, Spotfire is not very good at table exports. I have had some luck with increasing the page size (A4 or A5, for example) and using Landscape over Portrait. again, I recommend to view it in the application.

Can iPad2 use images of resolution 2048 x 1536 with no aesthetic problems?

I am developing an iOS application for iPad. Currently I am using images of resolution 2048×1536 px (iPad3 resolution). If I run this app on iPad2 or iPad1 will it get fitted to its resolution (1024×768 px)? Or should I use a 1024×768 images and specify image#2x for iPad3?
Since I only have iPad3 , cannot know how the images will be seen in the lower resolution devices. But it should work perfectly on them too.
Any help greatly appreciated. Please cite your sources.
You could try this in the simulator if you don't have a non-retina device.
It's certainly possible and will usually look fine (at least for photos, text and icons may look worse when scaled down), but you are wasting quite a lot of memory which is pretty scarce on an iPad 1 (it only has 256 MB), so you should usually also include non-retina images.
Automatically scaling down images typically results in visual artifacts, which is why the SDK includes an easy way to include different versions of any image, instead of just a single big one.
As far as I know, all iOS devices (within the same family) have resolutions that are multiples of each other so automatic scaling artifacts are somewhat mitigated, but it is still best to include the correct resolution.

iOS: how to reduce size of large PNG files

I'm currently optimizing my iOS app for the new iPad. Unfortunately by adding launch images for the iPad retina display the size of my ipa grows from 1.2MB to 5.5MB, mainly because of the two PNG images in 1536 x 2008 (portrait) and 2048 x 1496 (landscape). The size of these images are respectivly 1.9MB and 1.7MB.
The portrait can be seen here: http://uploads.demaweb.dk/iPadPortrait.png.
As you may notice, the background is a fixed pattern but sadly it seems that this is not very compressible. I've further tried to compress the images using ImageOptim, but it does not make any difference after Xcode has compressed the images during the archive. Searching the web I've noticed, that some people are dissuading to turn off PNG compressing in Xcode.
Are there anything I can do? It is not a solution to change the pattern in the image to a solid color, as it should look like the background in my iOS view. But it seems odd, that supporting the new iPad increase the size by ~4MB.
I was able to get it down to 633KB with pngquant (64 colors with slight dithering, which is barely noticeable on regular screen, and should be absolutely invisible at Retina resolution) and ImageOptim.
Yes, you will need to disable Xcode's conversion to avoid Xcode inflating files by converting them to ARGB.
NB: the article quoted in the accepted answer provides no benchmarks at all for the claimed speed difference.
It also contains correction that it is possible to optimize images with ImageOptim for iOS apps.
I'm using a great tool called ImageOptim
It incorporates a number of tools inside which crush your png files significantly (in my case it was between 25% to 50%).
One thing to remember is to disable Xcode's PNG optimization (as explained on the website)
EDIT:
Simply drag the images to the imageOptim window and the optimization will start automatically
Ive struggled with this too, unfortunately not much can be done.
In an effort to dramatically increase drawing performance of iOS apps,
Xcode re-compresses PNG files as it builds. It premultiplies the alpha
channel and byte swaps the red, green and blue channels to be
sequenced blue, green and red. The result is optimised for iOS’s
purpose, but as a side effect, ImageOptim’s work gets undone…
Source

Vector art on iOS

We've now got 4-resolutions to support and my app needs at least 6 full-screen background images to be pretty. Don't want to break the bank on megabytes of images.
I see guides online about loading PDFs as images and custom SVG libraries but no discussion of prectically.
Here's the question: considering rendering speed and file size, what is the bet way to use vector images in iOS? And in addition, are there any practical caching or other considerations one should make in real world app development?
Something to consider for simple graphics, such as the type of thing used for backgrounds, etc., is just to render them at runtime using CG.
For example, in one of our apps, instead of including the typical repeating background tile image in all the required resolutions, we instead draw it once into a CGPatternRef, then convert it to a UIColor, at which point things become simple.
We still use graphic files for complex things, but for anything that's simple in nature, we just render it at runtime and cache the result, so we get resolution independence without gobs of image files. It's also made maintenance quite a bit easier.

Using vectors in iOS

I'm working on a simple iOS game that's always drawing 5 to 10 layers of 32bit png images which requires enough memory to crash on the ipod touch 4g when retina enabled. On other devices it works just fine. I'm not even getting memory warnings. So I was trying with lower quality images, like RGB5_A1 format, but it looks really bad because I need alpha transparency and lots of gradients.
Since all the images are exports from Illustrator I was thinking that maybe i could just export a vector image and draw in on iOS. From what i was researching hardly anyone tried this and the only option I've come across was to implement a SVG parser for Quartz.
Did I miss anything?
Also I'm worried about performance, but I couldn't find any benchmarks.
Without knowing specifics of your game, I'm going to make a few assumptions based on normal use...
You are not going to want to use straight vector graphics for this. Stick with your raster graphics.
If you are talking about 32 bit color space for your PNG images, then you need to scale back. iOS uses 24 bit images and that includes 8 bits each for red, green, blue, and alpha. As it stands, you have an extra byte for every pixel shown.
If you are using Adobe products, import the Illustrator file into Photoshop and use the "Save for Web..." option. Choose PNG-24 and you'll be all set.