Memory Allocation

You can construct an image using an internal or an external memory allocation.

Internal memory allocation

The image object dynamically allocates and deallocates a buffer:

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The memory management is transparent.

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When the image size changes, a reallocation occurs.

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When an image object is destroyed, the buffer is deallocated.

To declare an image with an internal memory allocation:

1.

Construct an image object, for instance EImageBW8, either with width and height arguments or using the SetSize function.

2.

Access a given pixel using one of the multiple available functions. For example, use GetImagePtr to retrieve a pointer to the first byte of the pixel at the given coordinates.

External memory allocation

Control the buffer allocation or link a third-party image in the memory buffer to an Open eVision image.

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You must specify the image size and the buffer address.

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When an image object is destroyed, the buffer is unaffected.

2

For details, see Image and Depth Map Buffer and Interfacing Third-Party Images.

To declare an image with an external memory allocation:

1.

Declare an image object, for instance EImageBW8.

2.

Create a suitably sized and aligned buffer.

3.

Assign the buffer to the image with SetImagePtr.

If your buffer rows are not aligned on 4 bytes, use InitializeFromUnalignedBuffer instead of SetImagePtr.
Please note that this allocates the memory internally and copies the external buffer into the internal one instead of using the external one.