MocrCalibrateFont

This function automatically calibrates the X and Y size and spacing of the font of a specified OCR font context to match that of a string in the sample target image. Note that these values can also be set manually with MocrControl() with M_TARGET_CHAR_SPACING, M_TARGET_CHAR_SIZE_X, and M_TARGET_CHAR_SIZE_Y. This function can only calibrate an M_CONSTRAINED OCR font context. You can change the type of context using MocrControl() with M_CONTEXT_CONVERT.

The sample image must contain the string specified in the String parameter, and both the size and spacing must be representative of the images to be read or verified with the calibrated OCR font context. This function might not return the expected results if the sample image contains more or fewer characters than the specified target string length (MocrControl() with M_STRING_SIZE).

The better the sample image, the better the calibration results. If a string cannot be located in the sample image, an error will be generated. Use MappGetError() to learn the error code and related information.

You can limit the operation to a region of the image buffer, using a rectangular region of interest (ROI) set using MbufSetRegion().

MocrCalibrateFont() should be called after defining a new OCR font context or when the character size in the target images changes.

The resulting target values are the best match between the minimum and the maximum target character sizes specified in the parameters of this function. Calibration will increment the minimum target character size by a step value until it reaches the maximum target character size. You can inquire the target character sizes and spacing with MocrInquire(). For best results, use a range of +/- 1 pixel with, for example, a step of between 0.1 and 0.2 pixels. Note that the greater the number of steps between the minimum and the maximum target character sizes, the longer this operation will take.