drawing.md

Simple Drawing Routines

This section includes simple routines to draw on images.

[res] image.drawText(src, text, x, y, [options])

Draws text onto a 3-channel Tensor (C x H x W) at the x-offset x and y-offset y.

The options table can be passed in to set color, background color, in-place etc.

Options:

• color - [table] The text color. A table of 3 numbers {R, G, B}, each number scaled between 0 and 255. For example, red is {255, 0, 0}
• bg - [table] The background color where text is drawn. Same format as color.
• size - [number] Size of the text to be drawn. Default value = 1.
• wrap - [boolean] If the text goes out of bounds, wrap it with a newline automatically. default value = true
• inplace - [boolean] If true, draws directly on the input tensor and returns it. default value = false

Example:

image.drawText(image.lena(), "hello\nworld", 10, 10)
image.drawText(image.lena(), "hello\nworld", 10, 20,{color = {0, 255, 0}, size = 5})
image.drawText(image.lena(), "hello\nworld", 10, 20,{color = {0, 255, 0}, bg = {255, 0, 0}, size = 5})

[res] image.drawRect(src, x1, y1, x2, y2, [options])

Draws a rectangle onto a 3-channel Tensor (C x H x W). The top-left corner of the rectangle is x1, y1, and the bottom-right corner is x2, y2.

The options table can be passed in to set color, in-place etc.

Options:

• color - [table] The rectangle color. A table of 3 numbers {R, G, B}, each number scaled between 0 and 255. For example, red is {255, 0, 0}
• lineWidth - [number] The width of the rectangle line, in pixels
• inplace - [boolean] If true, draws directly on the input tensor and returns it. default value = false

Example:

image.drawRect(image.lena(), 200, 200, 370, 400, {lineWidth = 5, color = {0, 255, 0}})