Image::Leptonica::Func::fpix2
version 0.04
fpix2.c
fpix2.c This file has these FPix utilities: - interconversions with pix, fpix, dpix - min and max values - integer scaling - arithmetic operations - set all - border functions - simple rasterop (source --> dest) - geometric transforms Interconversions between Pix, FPix and DPix FPIX *pixConvertToFPix() DPIX *pixConvertToDPix() PIX *fpixConvertToPix() PIX *fpixDisplayMaxDynamicRange() [useful for debugging] DPIX *fpixConvertToDPix() PIX *dpixConvertToPix() FPIX *dpixConvertToFPix() Min/max value l_int32 fpixGetMin() l_int32 fpixGetMax() l_int32 dpixGetMin() l_int32 dpixGetMax() Integer scaling FPIX *fpixScaleByInteger() DPIX *dpixScaleByInteger() Arithmetic operations FPIX *fpixLinearCombination() l_int32 fpixAddMultConstant() DPIX *dpixLinearCombination() l_int32 dpixAddMultConstant() Set all l_int32 fpixSetAllArbitrary() l_int32 dpixSetAllArbitrary() FPix border functions FPIX *fpixAddBorder() FPIX *fpixRemoveBorder() FPIX *fpixAddMirroredBorder() FPIX *fpixAddContinuedBorder() FPIX *fpixAddSlopeBorder() FPix simple rasterop l_int32 fpixRasterop() FPix rotation by multiples of 90 degrees FPIX *fpixRotateOrth() FPIX *fpixRotate180() FPIX *fpixRotate90() FPIX *fpixFlipLR() FPIX *fpixFlipTB() FPix affine and projective interpolated transforms FPIX *fpixAffinePta() FPIX *fpixAffine() FPIX *fpixProjectivePta() FPIX *fpixProjective() l_int32 linearInterpolatePixelFloat() Thresholding to 1 bpp Pix PIX *fpixThresholdToPix() Generate function from components FPIX *pixComponentFunction()
l_int32 dpixAddMultConstant ( DPIX *dpix, l_float64 addc, l_float64 multc )
dpixAddMultConstant() Input: dpix addc (use 0.0 to skip the operation) multc (use 1.0 to skip the operation) Return: 0 if OK, 1 on error Notes: (1) This is an in-place operation. (2) It can be used to multiply each pixel by a constant, and also to add a constant to each pixel. Multiplication is done first.
FPIX * dpixConvertToFPix ( DPIX *dpix )
dpixConvertToFPix() Input: dpix Return: fpix, or null on error
PIX * dpixConvertToPix ( DPIX *dpixs, l_int32 outdepth, l_int32 negvals, l_int32 errorflag )
dpixConvertToPix() Input: dpixs outdepth (0, 8, 16 or 32 bpp) negvals (L_CLIP_TO_ZERO, L_TAKE_ABSVAL) errorflag (1 to output error stats; 0 otherwise) Return: pixd, or null on error Notes: (1) Use @outdepth = 0 to programmatically determine the output depth. If no values are greater than 255, it will set outdepth = 8; otherwise to 16 or 32. (2) Because we are converting a float to an unsigned int with a specified dynamic range (8, 16 or 32 bits), errors can occur. If errorflag == TRUE, output the number of values out of range, both negative and positive. (3) If a pixel value is positive and out of range, clip to the maximum value represented at the outdepth of 8, 16 or 32 bits.
l_int32 dpixGetMax ( DPIX *dpix, l_float64 *pmaxval, l_int32 *pxmaxloc, l_int32 *pymaxloc )
dpixGetMax() Input: dpix &maxval (<optional return> max value) &xmaxloc (<optional return> x location of max) &ymaxloc (<optional return> y location of max) Return: 0 if OK; 1 on error
l_int32 dpixGetMin ( DPIX *dpix, l_float64 *pminval, l_int32 *pxminloc, l_int32 *pyminloc )
dpixGetMin() Input: dpix &minval (<optional return> min value) &xminloc (<optional return> x location of min) &yminloc (<optional return> y location of min) Return: 0 if OK; 1 on error
DPIX * dpixLinearCombination ( DPIX *dpixd, DPIX *dpixs1, DPIX *dpixs2, l_float32 a, l_float32 b )
dpixLinearCombination() Input: dpixd (<optional>; this can be null, equal to dpixs1, or different from dpixs1) dpixs1 (can be == to dpixd) dpixs2 a, b (multiplication factors on dpixs1 and dpixs2, rsp.) Return: dpixd always Notes: (1) Computes pixelwise linear combination: a * src1 + b * src2 (2) Alignment is to UL corner. (3) There are 3 cases. The result can go to a new dest, in-place to dpixs1, or to an existing input dest: * dpixd == null: (src1 + src2) --> new dpixd * dpixd == dpixs1: (src1 + src2) --> src1 (in-place) * dpixd != dpixs1: (src1 + src2) --> input dpixd (4) dpixs2 must be different from both dpixd and dpixs1.
DPIX * dpixScaleByInteger ( DPIX *dpixs, l_int32 factor )
dpixScaleByInteger() Input: dpixs (low resolution, subsampled) factor (scaling factor) Return: dpixd (interpolated result), or null on error Notes: (1) The width wd of dpixd is related to ws of dpixs by: wd = factor * (ws - 1) + 1 (and ditto for the height) We avoid special-casing boundary pixels in the interpolation by constructing fpixd by inserting (factor - 1) interpolated pixels between each pixel in fpixs. Then wd = ws + (ws - 1) * (factor - 1) (same as above) This also has the advantage that if we subsample by @factor, throwing out all the interpolated pixels, we regain the original low resolution dpix.
l_int32 dpixSetAllArbitrary ( DPIX *dpix, l_float64 inval )
dpixSetAllArbitrary() Input: dpix val (to set at each pixel) Return: 0 if OK, 1 on error
FPIX * fpixAddBorder ( FPIX *fpixs, l_int32 left, l_int32 right, l_int32 top, l_int32 bot )
fpixAddBorder() Input: fpixs left, right, top, bot (pixels on each side to be added) Return: fpixd, or null on error Notes: (1) Adds border of '0' 32-bit pixels
FPIX * fpixAddContinuedBorder ( FPIX *fpixs, l_int32 left, l_int32 right, l_int32 top, l_int32 bot )
fpixAddContinuedBorder() Input: fpixs left, right, top, bot (pixels on each side to be added) Return: fpixd, or null on error Notes: (1) This adds pixels on each side whose values are equal to the value on the closest boundary pixel.
FPIX * fpixAddMirroredBorder ( FPIX *fpixs, l_int32 left, l_int32 right, l_int32 top, l_int32 bot )
fpixAddMirroredBorder() Input: fpixs left, right, top, bot (pixels on each side to be added) Return: fpixd, or null on error Notes: (1) See pixAddMirroredBorder() for situations of usage.
l_int32 fpixAddMultConstant ( FPIX *fpix, l_float32 addc, l_float32 multc )
fpixAddMultConstant() Input: fpix addc (use 0.0 to skip the operation) multc (use 1.0 to skip the operation) Return: 0 if OK, 1 on error Notes: (1) This is an in-place operation. (2) It can be used to multiply each pixel by a constant, and also to add a constant to each pixel. Multiplication is done first.
FPIX * fpixAddSlopeBorder ( FPIX *fpixs, l_int32 left, l_int32 right, l_int32 top, l_int32 bot )
fpixAddSlopeBorder() Input: fpixs left, right, top, bot (pixels on each side to be added) Return: fpixd, or null on error Notes: (1) This adds pixels on each side whose values have a normal derivative equal to the normal derivative at the boundary of fpixs.
FPIX * fpixAffine ( FPIX *fpixs, l_float32 *vc, l_float32 inval )
fpixAffine() Input: fpixs (8 bpp) vc (vector of 8 coefficients for projective transformation) inval (value brought in; typ. 0) Return: fpixd, or null on error
FPIX * fpixAffinePta ( FPIX *fpixs, PTA *ptad, PTA *ptas, l_int32 border, l_float32 inval )
fpixAffinePta() Input: fpixs (8 bpp) ptad (4 pts of final coordinate space) ptas (4 pts of initial coordinate space) border (size of extension with constant normal derivative) inval (value brought in; typ. 0) Return: fpixd, or null on error Notes: (1) If @border > 0, all four sides are extended by that distance, and removed after the transformation is finished. Pixels that would be brought in to the trimmed result from outside the extended region are assigned @inval. The purpose of extending the image is to avoid such assignments. (2) On the other hand, you may want to give all pixels that are brought in from outside fpixs a specific value. In that case, set @border == 0.
DPIX * fpixConvertToDPix ( FPIX *fpix )
fpixConvertToDPix() Input: fpix Return: dpix, or null on error
PIX * fpixConvertToPix ( FPIX *fpixs, l_int32 outdepth, l_int32 negvals, l_int32 errorflag )
fpixConvertToPix() Input: fpixs outdepth (0, 8, 16 or 32 bpp) negvals (L_CLIP_TO_ZERO, L_TAKE_ABSVAL) errorflag (1 to output error stats; 0 otherwise) Return: pixd, or null on error Notes: (1) Use @outdepth = 0 to programmatically determine the output depth. If no values are greater than 255, it will set outdepth = 8; otherwise to 16 or 32. (2) Because we are converting a float to an unsigned int with a specified dynamic range (8, 16 or 32 bits), errors can occur. If errorflag == TRUE, output the number of values out of range, both negative and positive. (3) If a pixel value is positive and out of range, clip to the maximum value represented at the outdepth of 8, 16 or 32 bits.
PIX * fpixDisplayMaxDynamicRange ( FPIX *fpixs )
fpixDisplayMaxDynamicRange() Input: fpixs Return: pixd (8 bpp), or null on error
FPIX * fpixFlipTB ( FPIX *fpixd, FPIX *fpixs )
fpixFlipTB() Input: fpixd (<optional>; can be null, equal to fpixs, or different from fpixs) fpixs Return: fpixd, or null on error Notes: (1) This does a top-bottom flip of the image, which is equivalent to a rotation out of the plane about a horizontal line through the image center. (2) There are 3 cases for input: (a) fpixd == null (creates a new fpixd) (b) fpixd == fpixs (in-place operation) (c) fpixd != fpixs (existing fpixd) (3) For clarity, use these three patterns, respectively: (a) fpixd = fpixFlipTB(NULL, fpixs); (b) fpixFlipTB(fpixs, fpixs); (c) fpixFlipTB(fpixd, fpixs); (4) If an existing fpixd is not the same size as fpixs, the image data will be reallocated.
l_int32 fpixGetMax ( FPIX *fpix, l_float32 *pmaxval, l_int32 *pxmaxloc, l_int32 *pymaxloc )
fpixGetMax() Input: fpix &maxval (<optional return> max value) &xmaxloc (<optional return> x location of max) &ymaxloc (<optional return> y location of max) Return: 0 if OK; 1 on error
l_int32 fpixGetMin ( FPIX *fpix, l_float32 *pminval, l_int32 *pxminloc, l_int32 *pyminloc )
fpixGetMin() Input: fpix &minval (<optional return> min value) &xminloc (<optional return> x location of min) &yminloc (<optional return> y location of min) Return: 0 if OK; 1 on error
FPIX * fpixLinearCombination ( FPIX *fpixd, FPIX *fpixs1, FPIX *fpixs2, l_float32 a, l_float32 b )
fpixLinearCombination() Input: fpixd (<optional>; this can be null, equal to fpixs1, or different from fpixs1) fpixs1 (can be == to fpixd) fpixs2 a, b (multiplication factors on fpixs1 and fpixs2, rsp.) Return: fpixd always Notes: (1) Computes pixelwise linear combination: a * src1 + b * src2 (2) Alignment is to UL corner. (3) There are 3 cases. The result can go to a new dest, in-place to fpixs1, or to an existing input dest: * fpixd == null: (src1 + src2) --> new fpixd * fpixd == fpixs1: (src1 + src2) --> src1 (in-place) * fpixd != fpixs1: (src1 + src2) --> input fpixd (4) fpixs2 must be different from both fpixd and fpixs1.
FPIX * fpixProjective ( FPIX *fpixs, l_float32 *vc, l_float32 inval )
fpixProjective() Input: fpixs (8 bpp) vc (vector of 8 coefficients for projective transformation) inval (value brought in; typ. 0) Return: fpixd, or null on error
FPIX * fpixProjectivePta ( FPIX *fpixs, PTA *ptad, PTA *ptas, l_int32 border, l_float32 inval )
fpixProjectivePta() Input: fpixs (8 bpp) ptad (4 pts of final coordinate space) ptas (4 pts of initial coordinate space) border (size of extension with constant normal derivative) inval (value brought in; typ. 0) Return: fpixd, or null on error Notes: (1) If @border > 0, all four sides are extended by that distance, and removed after the transformation is finished. Pixels that would be brought in to the trimmed result from outside the extended region are assigned @inval. The purpose of extending the image is to avoid such assignments. (2) On the other hand, you may want to give all pixels that are brought in from outside fpixs a specific value. In that case, set @border == 0.
l_int32 fpixRasterop ( FPIX *fpixd, l_int32 dx, l_int32 dy, l_int32 dw, l_int32 dh, FPIX *fpixs, l_int32 sx, l_int32 sy )
fpixRasterop() Input: fpixd (dest fpix) dx (x val of UL corner of dest rectangle) dy (y val of UL corner of dest rectangle) dw (width of dest rectangle) dh (height of dest rectangle) fpixs (src fpix) sx (x val of UL corner of src rectangle) sy (y val of UL corner of src rectangle) Return: 0 if OK; 1 on error. Notes: (1) This is similiar in structure to pixRasterop(), except it only allows copying from the source into the destination. For that reason, no op code is necessary. Additionally, all pixels are 32 bit words (float values), which makes the copy very simple. (2) Clipping of both src and dest fpix are done automatically. (3) This allows in-place copying, without checking to see if the result is valid: use for in-place with caution!
FPIX * fpixRemoveBorder ( FPIX *fpixs, l_int32 left, l_int32 right, l_int32 top, l_int32 bot )
fpixRemoveBorder() Input: fpixs left, right, top, bot (pixels on each side to be removed) Return: fpixd, or null on error
FPIX * fpixRotate180 ( FPIX *fpixd, FPIX *fpixs )
fpixRotate180() Input: fpixd (<optional>; can be null, equal to fpixs, or different from fpixs) fpixs Return: fpixd, or null on error Notes: (1) This does a 180 rotation of the image about the center, which is equivalent to a left-right flip about a vertical line through the image center, followed by a top-bottom flip about a horizontal line through the image center. (2) There are 3 cases for input: (a) fpixd == null (creates a new fpixd) (b) fpixd == fpixs (in-place operation) (c) fpixd != fpixs (existing fpixd) (3) For clarity, use these three patterns, respectively: (a) fpixd = fpixRotate180(NULL, fpixs); (b) fpixRotate180(fpixs, fpixs); (c) fpixRotate180(fpixd, fpixs);
FPIX * fpixRotate90 ( FPIX *fpixs, l_int32 direction )
fpixRotate90() Input: fpixs direction (1 = clockwise, -1 = counter-clockwise) Return: fpixd, or null on error Notes: (1) This does a 90 degree rotation of the image about the center, either cw or ccw, returning a new pix. (2) The direction must be either 1 (cw) or -1 (ccw).
FPIX * fpixRotateOrth ( FPIX *fpixs, l_int32 quads )
fpixRotateOrth() Input: fpixs quads (0-3; number of 90 degree cw rotations) Return: fpixd, or null on error
FPIX * fpixScaleByInteger ( FPIX *fpixs, l_int32 factor )
fpixScaleByInteger() Input: fpixs (low resolution, subsampled) factor (scaling factor) Return: fpixd (interpolated result), or null on error Notes: (1) The width wd of fpixd is related to ws of fpixs by: wd = factor * (ws - 1) + 1 (and ditto for the height) We avoid special-casing boundary pixels in the interpolation by constructing fpixd by inserting (factor - 1) interpolated pixels between each pixel in fpixs. Then wd = ws + (ws - 1) * (factor - 1) (same as above) This also has the advantage that if we subsample by @factor, throwing out all the interpolated pixels, we regain the original low resolution fpix.
l_int32 fpixSetAllArbitrary ( FPIX *fpix, l_float32 inval )
fpixSetAllArbitrary() Input: fpix val (to set at each pixel) Return: 0 if OK, 1 on error
PIX * fpixThresholdToPix ( FPIX *fpix, l_float32 thresh )
fpixThresholdToPix() Input: fpix thresh Return: pixd (1 bpp), or null on error Notes: (1) For all values of fpix that are <= thresh, sets the pixel in pixd to 1.
l_int32 linearInterpolatePixelFloat ( l_float32 *datas, l_int32 w, l_int32 h, l_float32 x, l_float32 y, l_float32 inval, l_float32 *pval )
linearInterpolatePixelFloat() Input: datas (ptr to beginning of float image data) wpls (32-bit word/line for this data array) w, h (of image) x, y (floating pt location for evaluation) inval (float value brought in from the outside when the input x,y location is outside the image) &val (<return> interpolated float value) Return: 0 if OK, 1 on error Notes: (1) This is a standard linear interpolation function. It is equivalent to area weighting on each component, and avoids "jaggies" when rendering sharp edges.
FPIX * pixComponentFunction ( PIX *pix, l_float32 rnum, l_float32 gnum, l_float32 bnum, l_float32 rdenom, l_float32 gdenom, l_float32 bdenom )
pixComponentFunction() Input: pix (32 bpp rgb) rnum, gnum, bnum (coefficients for numerator) rdenom, gdenom, bdenom (coefficients for denominator) Return: fpixd, or null on error Notes: (1) This stores a function of the component values of each input pixel in @fpixd. (2) The function is a ratio of linear combinations of component values. There are two special cases for denominator coefficients: (a) The denominator is 1.0: input 0 for all denominator coefficients (b) Only one component is used in the denominator: input 1.0 for that denominator component and 0.0 for the other two. (3) If the denominator is 0, multiply by an arbitrary number that is much larger than 1. Choose 256 "arbitrarily".
DPIX * pixConvertToDPix ( PIX *pixs, l_int32 ncomps )
pixConvertToDPix() Input: pix (1, 2, 4, 8, 16 or 32 bpp) ncomps (number of components: 3 for RGB, 1 otherwise) Return: dpix, or null on error Notes: (1) If colormapped, remove to grayscale. (2) If 32 bpp and @ncomps == 3, this is RGB; convert to luminance. In all other cases the src image is treated as having a single component of pixel values.
FPIX * pixConvertToFPix ( PIX *pixs, l_int32 ncomps )
pixConvertToFPix() Input: pix (1, 2, 4, 8, 16 or 32 bpp) ncomps (number of components: 3 for RGB, 1 otherwise) Return: fpix, or null on error Notes: (1) If colormapped, remove to grayscale. (2) If 32 bpp and @ncomps == 3, this is RGB; convert to luminance. In all other cases the src image is treated as having a single component of pixel values.
Zakariyya Mughal <zmughal@cpan.org>
This software is copyright (c) 2014 by Zakariyya Mughal.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
To install Image::Leptonica, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Image::Leptonica
CPAN shell
perl -MCPAN -e shell install Image::Leptonica
For more information on module installation, please visit the detailed CPAN module installation guide.