CODEWITHSUNDEEP
iosios7
user3396988
user3396988

Reputation: 55

Is there a maximum image width in iOS (image I have is 25020 x 238)? Image works when resized

This image (https://i.sstatic.net/HIJOY.jpg) will not load in the simulator, although when I scale it to half the size it loads just fine. When trying to load the full image I just get a black box where it should be.

Upvotes: 1

Views: 1705

Answers (3)

user2067021
user2067021

Reputation: 4539

Just to expand a bit on the other answers.

The UIImage documentation (as of iOS 10) no longer seems to mention size limitations, although if you use UIImageView with images whose dimensions are larger than the maximum texture size* supported by the device you happen to be using you do get very large memory consumption at render time.

(The memory consumption I see in Instruments seems to indicate that the entire image is put into a 32 bits per pixel buffer when the CA::Layer is rendered.)

If your app doesn't get kill by the OS due to memory usage, the UIImageView does still end up displaying the image though.

Given this, you'll still need strategies to deal with very large images.

* You can check the maximum texture size using something like glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);. Just make sure you've set the EAGLContext current context to be something non-nil before querying OpenGL, otherwise you'll get zero.

Upvotes: 0

indragie
indragie

Reputation: 18132

It might be that you are hitting some limits on the maximum size of the CALayer (which in turn is dependent on the maximum OpenGL texture size supported by the hardware) that is backing the view. If you're exceeding the maximum size, a message like CoreAnimation: surface <size> is too large will be logged. It's also possible that the decompressed image may be too large to fit in memory. You should use CATiledLayer to display content of that size to ensure that it stays within the resource constraints of the device.

Upvotes: 1

nneonneo
nneonneo

Reputation: 179697

Yes, there is a maximum image size (number of pixels). The limit depends on the hardware in part, but it is generally in the range of 5 to 10 million pixels. This limit is related to limitations on the maximum sizes of textures that can be sent to the graphics card; therefore, it only applies to images that are drawn.

From the documentation:

You should avoid creating UIImage objects that are greater than 1024 x 1024 in size. Besides the large amount of memory such an image would consume, you may run into problems when using the image as a texture in OpenGL ES or when drawing the image to a view or layer. This size restriction does not apply if you are performing code-based manipulations, such as resizing an image larger than 1024 x 1024 pixels by drawing it to a bitmap-backed graphics context. In fact, you may need to resize an image in this manner (or break it into several smaller images) in order to draw it to one of your views.

Upvotes: 1

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